Brazilian Pharmacopoeia: 6 Edition
Brazilian Pharmacopoeia: 6 Edition
Brazilian Pharmacopoeia: 6 Edition
PHARMACOPOEIA
6th EDITION
Brazilian
Pharmacopoeia
6th edition
Volume I
Brasilia
2019
Full or partial reproduction of this work is allowed provided that the source is cited.
The printing, distribution, reproduction of this work for commercial purposes is prohibited without
the prior and express consent of Anvisa.
Director-President
William Dib
Directors
Alessandra Bastos Soares
Antônio Barra Torres
Fernando Mendes Garcia Neto
Renato Alencar Porto
Pharmacopoeia Coordinator
Arthur Leonardo Lopes da Silva
SUMMARY
Volume 1
1 PREFACE ......................................................................................................................................... 6
2 HISTORY ......................................................................................................................................... 8
3 BRAZILIAN PHARMACOPOEIA.................................................................................................. 9
4 MISCELLANEOUS ....................................................................................................................... 24
5 GENERAL METHODS .................................................................................................................. 23
5.1 METHODS APPLIED TO PHARMACEUTICAL PREPARATIONS ...................................... 23
5.2 PHYSICAL AND PHYSICAL-CHEMICAL METHODS ......................................................... 23
5.3 CHEMICAL METHODS ............................................................................................................ 23
5.4 METHODS OF PHARMACOGNOSIS ..................................................................................... 23
5.5 BIOLOGICAL METHODS, BIOLOGICAL AND MICROBIOLOGICAL ASSAYS .............. 23
5.6 IMMUNOCHEMICAL METHODS ........................................................................................... 92
5.7 PHYSICAL METHODS APPLIED TO SURGICAL AND HOSPITAL MATERIALS ........... 95
5.8 GENERAL METHODS APPLIED TO MEDICINAL GASES ................................................ 103
6 CONTAINERS FOR MEDICINES AND CORRELATES ......................................................... 108
6.1 GLASS CONTAINERS ............................................................................................................. 108
6.2 PLASTIC CONTAINERS ......................................................................................................... 115
7 REAGENTS .................................................................................................................................. 157
7.1 INDICATORS AND TEST SOLUTIONS ................................................................................ 157
7.2 REAGENTS AND REAGENT SOLUTIONS .......................................................................... 172
7.3 VOLUMETRIC SOLUTIONS .................................................................................................. 306
7.4 BUFFERS .................................................................................................................................. 315
8 GENERAL INFORMATION ....................................................................................................... 321
8.1 STERILE PRODUCTS .............................................................................................................. 322
8.2 STATISTIC PROCEDURES APPLICABLE TO BIOLOGICAL ASSAYS ........................... 349
8.3 RADIOPHARMACEUTICALS ................................................................................................ 399
8.4 PHARMACEUTICAL EQUIVALENCE AND BIOEQUIVALENCE OF MEDICINES ....... 419
8.5 WATER FOR PHARMACEUTICAL USE .............................................................................. 424
8.6 CHEMICAL REFERENCE SUBSTANCES ............................................................................ 436
8.7 COLORING AGENTS .............................................................................................................. 438
8.8 MEDICAL GASES .................................................................................................................... 453
8.9 DETERMINATION OF SOLUBILITY APPLIED TO BIOWAIVER ACCORDING TO THE
BIOPHARMACEUTICAL CLASSIFICATION SYSTEM ..................................................... 461
8.10 ALTERNATIVE MICROBIOLOGICAL ASSAYS ............................................................... 465
ANNEX A – PERIODIC TABLE OF CHEMICAL ELEMENTS – NAMES, SYMBOLS AND
Volume 2
MONOGRAPHS
1 PREFACE
0B
Brazilian Pharmacopoeia (FB) is the national pharmaceutical compendium that establishes, via
pharmacopoeial texts (chapters, methods and monographs), the minimum requirements for quality,
authenticity and purity of pharmaceutical ingredients, drugs and other products subject to sanitary
regulation. Failure to fully complying with the pharmacopoeial requirements may result in the product
being classified as altered, adulterated or inappropriate for use, under the terms of Law 6.360/76, with
those responsible incurring the sanctions and measures established in Law 6.437/77.
As technical-scientific development, by its very nature, is very dynamic and fast-moving, it is crucial
that we have a pharmacopoeial compendium that fits simultaneously into pharmaceutical innovations.
Since the 5th edition of FB, published on November 23, 2010, the Deliberative Council of the
Brazilian Pharmacopoeia (CDFB) has been working day-to-day in the fulfillment of its mission to
keep FB constantly updated.
The 1st errata of the 5th edition of the FB (RDC 18/2012) was published In 2012 with some specific
corrections.
In 2016, RDC 59, on February 03, and RDC 101, on August 12th, were published, thus approving
the First Supplement of the FB 5th edition. This supplement comprised 63 pharmacopoeial texts, 8
general texts/methods, 7 of which were unpublished, and 55 monographs, of which 38 were
unpublished. This edition increased the number of FB monographs by about 10%, and covered
monographs on synthetic drugs (16, 6 unpublished), biological drugs (15, being 12 unpublished),
blood components/blood derivatives (7 unpublished) and pharmaceutical ingredients (17, 13 of which
were unpublished). This publication highlights the incorporation of 6 general methods harmonized
within the scope of the Mercosur Pharmacopoeia (Common Market Group).
In 2017, RDC 167 of 24 July was published, which approved the Second Supplement of the FB 5th
edition. This supplement comprised 262 pharmacopoeial texts, 12 chapters and general methods, 8 of
which were unpublished, and 247 monographs, of which 176 were unpublished. This edition raised
the number of FB monographs by about 25%, and covered monographs on medical devices (03
unpublished), medical gases (02 unpublished), radiopharmaceuticals (03 unpublished), blood
components (05 unpublished), synthetic drugs (11 new), biological drugs (18, 5 new), pharmaceutical
ingredients (61, 58 new) and medicinal plants (147, 89 new). It is worth noting that the 58 monographs
on medicinal plants from the 5th edition of the FB were duly revised, and there was also an increase
of about 150% in the number of monographs in this class of products, fostering the development of
products of plant origin and valuing the native flora. Still, in an unprecedented action, this supplement
comprises the two prime monographs, and the respective chapter and general methods, of medical
gases, a drug class not covered by FB yet.
In 2018 there was already content for a new supplementary update, with 15 new monographs of
synthetic drugs (07), medical gases (02), active ingredient (01), medicinal plants (02), biological
product (01) and radiopharmaceuticals (02). The desire to maintain a perennial annual update process
was moderated by the urgent need to review and update the hundreds of pharmacopoeial texts in the
5th edition.
Accordingly, FB Deliberative Council decided to conduct a broad review process, which culminated
in this FB 6th edition. This 6th edition comes with a new and modern visual identity, compatible with
the relevance of this work, combined with a 100% digital publication.
Here, it is vital to praise the outstanding commitment of the Thematic Technical Committees (CTT)
in carrying out such undertaking, which, despite the tight deadline, concluded the mission with
honors.
Finally, we highlight Anvisa's support in promoting this work, in particular to the Pharmacopoeia
Coordination (Cofar) team, whose dedication and extreme care were essential.
2 HISTORY
1B
Brazil, as a Portuguese domain, used as its official pharmaceutical code the General Pharmacopoeia
of the Kingdom and Domains, published in 1794, and reprinted in 1824. In 1837 the French Codex
Medicamentarius was also accepted in Brazil. On September 29, 1851, the Decree 828 established
the French Codex Medicamentarius as the official compendium of Brazil, in addition to the
recognition of the Portuguese Pharmacopoeia. On January 19, 1882, Decree 8387, and on December
31, 1923, Decree 16,300 reaffirmed the primacy and authority of the French Pharmacopoeia.
The 1st edition of the Brazilian Pharmacopoeia was approved on November 04, 1926, by Decree
17.509. This 1st edition was updated in 1943 – 1st supplement – (Ordinance nr 42, of March 2nd), in
1945 – 2nd supplement – (Ordinance nr 24, of April 14) and in 1950 – 3rd supplement – (Ordinance
nr 39, of June 13).
The 2nd edition of the Brazilian Pharmacopoeia was approved in 1955 (Decree 37,843, of September
1st), and had updates and modifications in 1959 (Decree 45,502, of February 27th), with the
separation of pharmaceutical formulations from the Pharmacopoeia at that time, thus emerging the
National Form.
The 3rd edition of the Brazilian Pharmacopoeia was approved in 1976 (Decree 78,840, of 25
November).
The 4th edition of the Brazilian Pharmacopoeia (Part I) was approved in 1988 (Decree 96,607, of 30
August). Part II was published in fascicles in 1996 (first), 2000 (second), 2002 (third), 2003 (fourth),
2004 (fifth) and 2005 (sixth).
The 5th edition of the Brazilian Pharmacopoeia was approved in 2010 (Resolution of the Collegiate
Board – RDC 49, of November 23). In 2012, the 1st erratum was approved (RDC 18, of March 23).
The 5th edition was further complemented by the 1st Supplement in 2016 (RDC 59/2016 and RDC
101/2016) and by the 2nd Supplement in 2017 (RDC 167/2017).
Without further details, we have here a brief time recap of the evolution of this National Compendium.
3 BRAZILIAN PHARMACOPOEIA
2B
PRESIDENT
VARLEY DIAS SOUSA
VICE-PRESIDENT
CLÉVIA FERREIRA DUARTE GARROTE
MEMBERS
ADRIANO ANTUNES DE SOUZA ARAÚJO
Universidade Federal de Sergipe - UFS
PHARMACOPOEIA COORDINATION
BRAZILIAN HEALTH REGULATORY AGENCY – Anvisa
Administrative technician
VOLKER BITTRICH
Universidade Estadual de Campinas –
Unicamp
4 MISCELLANEOUS
3B
TITLE
The full title of this work is “Pharmacopoeia of the Federative Republic of Brazil, 6th edition”. It may
be called “Brazilian Pharmacopoeia, 6th edition” or FB 6.
DEFINITIONS
The ones contained in the report for registration of the product at the sanitary agency, updated through
a national and international bibliographic review, when applicable.
When indicated in the monographs, the doses represent the amount of medication usually prescribed¸
that has therapeutic efficacy for adult patients. The qualified prescriber, at his discretion and under
his sole responsibility, considering pharmacokinetic and pharmacodynamic criteria, may vary the
amounts and administration frequency of any medication. However, the prescription of doses much
higher than the usual ones, established in the literature, leads the pharmacist to confirm, with the
prescriber of the prescription, the established doses.
A solution is considered neutral when it does not change the color of the blue and red litmus papers,
or when the universal indicator paper shows the colors of the neutral scale, or when 1 mL of the same
solution is colored green with a drop of bromothymol blue TS (pH 7.0).
It is considered acidic when the blue litmus paper is stained red or 1 mL is stained yellow by a drop
of phenol red TS (pH 1.0 to 6.6).
It is considered weakly acidic when the blue litmus paper is slightly stained red or 1 mL is stained
orange by a drop of methyl red TS (pH 4.0 to 6.6).
It is considered strongly acidic when the Congo red paper is stained blue or 1 mL is stained red by
the addition of a drop of methyl orange TS (pH 1.0 to 4.0).
It is considered alkaline when the red litmus paper is stained blue or 1 mL is stained blue by a drop
of bromothymol blue TS (pH 7.6 to 13.0).
It is considered weakly alkaline when the red litmus paper is stained blue or 1 mL is stained pink by
a drop of cresol red TS (pH 7.6 to 8.8).
It is considered strongly alkaline when stained blue by a drop of thymolphthalein TS (pH 9.3 to 10.5)
or red by a drop of phenolphthalein TS (pH 10.0 to 13.0).
Adhesive
It is the system designed to produce a systemic effect by diffusing the active principle(s) at a constant
rate/speed for an extended period of time.
Water for injections is the liquid used in the preparation of drugs for parenteral administration, as a
vehicle, or in the dissolution and dilution of substances or preparations.
Water for pharmaceutical purposes is the various types of water used in the synthesis of drugs, in the
formulation and production of drugs, in testing laboratories, diagnostics and other applications related
to the health area, including as a main component in the cleaning of utensils, equipment and systems.
Purified water
Purified water is drinking water that has undergone some type of treatment to remove possible
contaminants and meet the purity requirements established in the monograph.
Ultrapure water
Ultrapure water is purified water that has undergone additional treatment to remove potential
contaminants and meet the purity requirements established in the monograph.
Aromatic waters
They are saturated solutions of essential oils or other aromatic substances in water. They have a
characteristic smell of the substances they are prepared with, also receiving their name.
It is a boiling water bath, unless the monograph specifies another temperature. The expressions hot
water and very hot water indicate approximate temperatures between 60ºC and 70ºC and between
85ºC and 95ºC, respectively. Steam bath means exposure to flowing steam or another form of heat,
corresponding in temperature to that of flowing steam.
Bioavailability
It indicates the speed and extent of absorption of an active ingredient in a dosage form, based on its
concentration/time curve in the systemic circulation or its excretion in the urine.
Bioequivalence
It consists of proving pharmaceutical equivalence between products presented under the same
pharmaceutical preparation, containing identical qualitative and quantitative composition of active
principle(s), and which have comparable bioavailability, when studied under the same experimental
design.
Tank truck
Capsule
It is the solid pharmaceutical preparation in which the active ingredient and excipients are contained
in a hard or soft soluble envelope, of varying shapes and sizes, usually containing a single dose of the
active ingredient. It is usually made of gelatin, but it can also be made of starch or other substances.
Hard capsule
It is the capsule that consists of two prefabricated cylindrical sections (body and cap) that fit together
and whose ends are rounded. It is typically filled with active ingredients and excipients in solid form.
It is usually made of gelatin, but it can also be made of other substances.
It is the capsule that consists of two prefabricated cylindrical sections (body and cap) that fit together
and whose ends are rounded. It is typically filled with active ingredients and excipients in solid form.
It is usually made of gelatin, but it can also be made of other substances. See general definition of
prolonged release.
It is the capsule that consists of two prefabricated cylindrical sections (body and cap) that fit together
and whose ends are rounded. It is typically filled with active ingredients and excipients in solid form.
It is usually made of gelatin, but it can also be made of other substances. See general definition of
delayed release.
Soft capsule
It is a capsule made of a gelatin shell, of various shapes, which is more malleable than that of hard
capsules. They are usually filled with liquid or semi-solid contents, but can also be filled with powders
and other dry solids.
It is a capsule made of a gelatin shell, of various shapes, which is more malleable than that of hard
capsules. They are usually filled with liquid or semi-solid contents, but can also be filled with powders
and other dry solids. See general definition of prolonged release.
It is a capsule made of a gelatin shell, of various shapes, which is more malleable than that of hard
capsules. They are usually filled with liquid or semi-solid contents, but can also be filled with powders
and other dry solids. See general definition of delayed release.
CAS
Medicinal tea
It consists exclusively of herbal drugs intended for oral aqueous preparations by means of decoction,
infusion or maceration. The tea is prepared immediately before use.
Gas cylinder
It is the metallic container, perfectly closed, with resistant walls designed to contain gas under
pressure, closed by an adjustable valve capable of maintaining the gas output at a determined flow
rate.
Transportable and pressurized container with a capacity measured in water volume not exceeding 150
liters.
CNTP
Eye drops
It is a liquid pharmaceutical preparation intended for application over the ocular mucosa.
It is a fraction of plasmatic proteins that mandatorily contains Factors II, VII, IX and X of the human
coagulation.
Tablet
It is a solid pharmaceutical preparation containing a single dose of one or more active principles, with
or without excipients, obtained by compressing uniform volumes of particles. It can be of a wide
variety of sizes, shapes, have surface markings, and be coated or uncoated.
It is the tablet that has a modified release dosage. It should be classified as modified release only
when the classifications “delayed release” and “prolonged release” are not adequate.
It is the tablet whose excipients are specifically intended to modify the release of the active ingredient
in digestive fluids. See definition of prolonged release.
Effervescent tablet
It is the tablet that contains, in addition to the active ingredients, acidic substances and carbonates or
bicarbonates, which release carbon dioxide when the tablet is dissolved in water. It is intended to be
dissolved or dispersed in water prior to administration.
Chewable tablet
It is the tablet formulated so that it can be chewed, producing a pleasant aftertaste in the oral cavity.
Orodispersible tablet
It is the tablet that quickly disintegrates or dissolves when placed on the tongue.
Mouthwash tablet
It is the tablet that must be dissolved in water to prepare the mouthwash, which is a liquid for mouth
rinsing that acts on the gums and mucous membranes of the mouth and throat. It must not be
swallowed.
It is intended to be dissolved in water prior to administration. The preparation produced can be slightly
turbid due to the excipients used in the tablet manufacturing.
It is the tablet that, when in contact with a liquid, quickly produces a homogeneous dispersion
(suspension) and must be dispersed before administration.
Coated tablet
It is the tablet that has one or more thin coating layers, usually polymeric, designed to protect the drug
from air or humidity; for drugs with unpleasant odor and taste; to improve the appearance of the
tablets, or for some other property other than altering the speed or extent of the active ingredient
release.
It is the tablet that has one or more thin coating layers, usually polymeric, designed to modify the
speed or extent of release of the active ingredients. See general definition of prolonged release.
It is the tablet that has one or more thin coating layers, usually polymeric, designed to modify the
speed or extent of the release of the active ingredients, presenting a delayed release of the active
ingredient. See definition of delayed release.
Uncoated tablet
It is the tablet in which excipients used are not specifically intended to modify the release of the active
ingredient in digestive fluids.
Quality control
It is the set of measures designed to guarantee, at any time, the production of batches of drugs and
other products that meet the standards of identity, activity, content, purity, efficacy and safety.
Dyes/Colorants
They are additional substances to drugs, diet products, cosmetics, perfumes, hygiene products and
similars, household sanitizers and similars, to give them color and, in certain types of cosmetics,
transfer it to the skin surface and skin appendages. For its use, observe the Federal legislation and the
resolutions issued by Anvisa.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition GN-00
Surgical materials
Health product, such as equipment, apparatus, material, article or system for medical, dental or
laboratory use or application, intended for the prevention, diagnosis, treatment, rehabilitation or
contraception and which does not use pharmacological, immunological or metabolic means to carry
out its main function in human beings being able, however, to be aided in its functions by such means.
Cosmetics
Products for external use; intended for the protection or beautification of different parts of the body,
such as facial powders; body powders; beauty creams; hand cream and similars; face masks; beauty
lotions; milky, creamy and astringent solutions; hand lotions; make-up foundation and cosmetic oils;
blushes; lipsticks; lip balms; sunscreens; tanning lotions; mascaras; eye shadows; eyeliners; hair dyes;
hair bleaching agents; hair curling and straightening preparations; hair fixatives; hairspray; shining
hair gels and similars; hair lotions; depilation and epilation products; nail preparations and others.
Cream
They are constituted by cold-insoluble fractions containing mainly Factors I (140 to 250 mg) and VIII
(70 to 120 IU) of human coagulation per unit of human blood collection. Other coagulation factors
are also found in lower concentrations with cryoprecipitate such as Von Willebrand Factor (40 to
70%) and Factor XIII (20 to 30%).
It is the name of the drug or pharmacologically active ingredient approved by the federal agency
responsible for health regulation. it also includes the names of inactive ingredients, hyperimmune
serums and vaccines, radiopharmaceuticals, medicinal plants, homeopathic and biological substances.
It is the name of the drug or pharmacologically active ingredient, recommended by the World Health
Organization.
Mass density (r) of a substance is the ratio of its mass to its volume at 20°C. The usually adopted
relative density (ρ) is defined as the ratio between the mass of a substance in the air at 20°C and the
mass of an equal volume of water at the same temperature.
Disinfectants
Detergents
Products designed to dissolve fats; the hygiene of containers and canisters and domestic applications.
Blood Donors
Healthy and carefully selected individuals who, after medical examinations, laboratory blood tests
and study of their medical history, are free of transmissible infectious agents can be accepted and
used to collect their whole blood or their cellular or plasma fractions for prophylactic purposes,
dressings or fractionation.
Tablets coated with layers consisting of mixtures of different substances, such as natural or synthetic
resins, gums, gelatins, inactive and insoluble materials, sugars, plasticizers, polyols, waxes,
authorized colorants and, sometimes, flavorings and active ingredients.
They are obtained from living beings such as plants, bacteria, algae, fungi, lichens, animals, and
minerals, which contain substances or classes of substances responsible for a therapeutic action and/or
pharmaceutical purpose. The drug is specified by the part used and the scientific name (species,
variety where applicable, and author(s)).
Herbal drugs
Herbal drugs are whole plants or their parts, usually dry, unprocessed, either whole or fragmented.
Exudates such as gums, resins, mucilage, latex and waxes that have not been subject to specific
treatment are also included.
Elixir
It is a pharmaceutical preparation for oral use, liquid, clear, hydroalcoholic, with a sweet and pleasant
taste. Elixirs are prepared by simple dissolution and must be stored in amber colored flasks and kept
in a cool place protected from light.
Packaging
It is the wrapping, container or any form of packaging, removable or not, intended to cover, package,
fill, protect or maintain, specifically or not, medicines, drugs, pharmaceutical and related ingredients,
cosmetics, sanitizers and other products.
Primary packaging
It is the one that maintains direct contact with its content. Examples of primary packaging: ampoule,
tube, envelope, case, flacon, glass or plastic flask, ampoule flask, cartridge, can, pot, paper bag,
among others. There must be no interaction whatsoever between the primary packaging material and
its contents capable of altering the concentration, quality or purity of the packaged material.
Secondary packaging
It is the one that allows total protection of the packaging material under the usual conditions of
transport, storage and distribution. Examples of secondary packaging: cardboard boxes, cardboard
cartridges, wood or plastic material or cardboard case and others.
Patch
It is the semi-solid pharmaceutical preparation for external application. It consists of an adhesive base
containing one or more active ingredients distributed in a uniform layer on an appropriate support
made of synthetic or natural material. Intended to keep the active ingredient in contact with the skin
acting as a protector or keratolytic agent.
Emulsion
It is the liquid pharmaceutical preparation of one or more active ingredients that consists of a two-
phase system involving at least two immiscible liquids and in which a liquid is dispersed in the form
of small drops (internal or dispersed phase) through another liquid (external or continuous phase). It
is usually stabilized by means of one or more emulsifying agents.
Aerosol emulsion
Emulsion drops
Injectable emulsion
It is a sterile emulsion with water as the continuous phase normally, isotonic with blood and used
primarily for large volume administration.
Spray emulsion
It is the emulsion administered in the form of a liquid finely divided by a jet of air or steam.
Biological assays
Procedures designed to assess the potency of active ingredients contained in raw materials and
pharmacopoeial preparations, using biological reagents such as microorganisms, animals, fluids and
isolated organs from animals.
Spirits
Sterility
Extracts
Semi-solid or solid liquid preparations, obtained from herbal drugs, using extraction methods and
appropriate solvents. An extract is essentially defined by the quality of the herbal drug, the production
process and its specifications. The material used in the preparation of extracts can undergo
preliminary treatments, such as enzyme inactivation, grinding or degreasing. After extraction,
unwanted materials can be eliminated.
Standardized extracts
Extracts adjusted to a defined content of one or more constituents responsible for the therapeutic
activity. Content adjustment is achieved by adding inert excipients or blending other batches of
extract.
Quantified extracts
Extracts adjusted to a content range of one or more active markers. Content range adjustment is
achieved by mixing extract batches.
Other Extracts
Extracts not adjusted to a specific content of constituents. They are essentially defined by the
parameters of their manufacturing process, such as the quality of the herbal drug, selection of the
extraction liquid and extraction condition as well as their specifications. Markers do not necessarily
have established therapeutic activity, being considered analytic markers. The content of the markers
must not be inferior to the minimum value indicated in the monograph.
Fluid extract
It is the liquid preparation obtained by extraction with an appropriate liquid in which, in general, a
part of the extract, by mass or volume, corresponds to a part, by mass, of the dry herbal drug used in
its preparation. Preservatives can also be added. They must present specifications regarding the
content of markers and dry residue. In the case of extracts classified as standardized, the proportion
between the herbal drug and the extract can be modified due to the necessary adjustments to obtain
the specified content of active constituents.
Soft extract
It is the semi-solid consistency preparation obtained by partial evaporation of the used extraction
liquid, and can be used as solvents, solely, ethyl alcohol, water, or mixtures of ethyl alcohol and water
in an adequate proportion. They have not less than 70% (w/w) of dry residue. Preservatives can be
added if necessary.
Extracts prepared without the addition of excipients (simple or crude extracts). However, for soft
extracts and liquid preparations, the native extract may have variable quantities of extraction liquid.
Dry extract
It is the solid preparation obtained by evaporating the solvent used in the extraction process. They
can be added from suitable inert materials and have specifications as to the content of markers. In
general, they have a desiccation loss of no more than 5% (w/w).
Manufacturing
Distillation range
Distillation range is the temperature range corrected for the pressure of 101.3 kPa (760 mm of Hg),
within which the liquid, or specific fraction of the liquid, fully boils.
Melting range
Melting range of a substance is the temperature range between the start (at which the substance begins
to liquefy) and the end of melting (which is evidenced by the disappearance of the solid phase).
Drug
Pharmacopoeial
The expression pharmacopoeial replaces the expressions official and officinal, used in previous
editions, being equivalent to such expressions for all purposes.
It is the protein fraction of plasma that contains Factor VII (a single-chain glycoprotein derivative),
which may also contain small quantities of its activated form (the two-chain derivative or Factor
VIIa).
It is a protein fraction of plasma that contains a glycoprotein called coagulation factor VIII and,
depending on the purification method, variable quantities of von Willebrand factor. It is prepared
from a mixture of plasma for fractionation obtained from healthy donors.
It is the soluble fraction of human plasma, obtained from human Plasma for fractionation, which, by
adding thrombin, is transformed into fibrin. The preparation may contain additives (salts, buffers or
stabilizers) and when reconstituted (addition of diluent) must contain not less than 10 g/L of
fibrinogen.
FISPQ
Pharmaceutical preparation
It is the final state of presentation of the active pharmaceutical ingredients after one or more
pharmaceutical operations carried out with the addition or not of appropriate excipients in order to
facilitate their use and obtain the desired therapeutic effect, with characteristics appropriate to a given
route of administration.
Gas
Substance or mixture of substances whose vapor pressure is above 300 kPa absolute at 50 °C or
remains in gaseous form at 20 °C at an absolute pressure of 101.3 kPa.
Compressed gas
Any gas or mixture of gases that exerts an absolute pressure greater than or equal to 280 kPa at 20 °C
in the container where the gas is stored.
Excipient gas
Any component gas, which is not an active substance, intentionally added to the formulation of a gas
mixture.
Liquefied gas
A gas at vapor pressure that remains partially liquefied at temperatures above –50°C.
Medicinal Gas
Gas, or mixture of gases, for treating or preventing disease in humans or administered for medical
diagnosis purposes or to restore; correct; or modify physiological functions.
Highly cooled gas in phase equilibrium (liquid and its vapor pressure) and boiling point less than or
equal to –150 °C at an absolute pressure of 101.3 kPa.
Gel
It is the semi-solid dosage form of one or more active ingredients that contains a gelling agent to
provide firmness to a colloidal solution or dispersion (a system in which particles of colloidal size –
typically between 1 nm and 1 mm – are evenly distributed throughout the liquid) and may contain
suspended particles.
Hydrophobic gel
It is the gel that usually consists of liquid paraffin with polyethylene or fatty oils with colloidal silica
or aluminum or zinc soaps.
Lipophilic gel
It is the gel resulting from the preparation obtained by the incorporation of gelling agents —
tragacanth, starch, cellulose derivatives, carboxyvinyl polymers and magnesium aluminum double-
chain silicates in water, glycerol or propylene glycol.
Globule
It is the solid pharmaceutical preparation that is presented in the form of small spheres made of
sucrose or a mixture of sucrose and lactose. They are impregnated with the desired potency and with
alcohol above 70%
Chewing gum
It is a single-dose solid pharmaceutical preparation containing one or more active ingredients, which
consists of insoluble, sweet and tasty plastic material. When chewed, it releases the active ingredient.
Granules
It is a solid pharmaceutical preparation containing a single dose of one or more active ingredients,
with or without excipients. It consists of solid and dry agglomerates of uniform volumes of powder
particles resistant to handling.
Effervescent granules
It is the granule that contains, in addition to the active ingredients, acidic substances and carbonates
or bicarbonates, which release carbon dioxide when the granule is dissolved in water. It is intended
to be dissolved or dispersed in water prior to administration.
It is the granule intended to be dissolved in water prior to administration. The preparation produced
can be slightly turbid due to the excipients used in the granule manufacture.
It is the granule that, in contact with a liquid, quickly produces a homogeneous dispersion
(suspension). It is intended to be dispersed prior to administration.
Coated granule
It is the granule that has one or more thin coating layers, usually polymeric, designed to protect the
drug from air or humidity; for drugs with unpleasant odor and taste; to improve the appearance of the
granules, or for some other property other than altering the speed or extent of the active ingredient
release.
It is the granule that has one or more thin coating layers, usually polymeric, designed to modify the
speed or extent of releasing the active ingredients. See definition of prolonged release.
It is the granule that has one or more thin coating layers, usually polymeric, designed to modify the
speed or extent of releasing the active ingredients, presenting a delayed release of the active
ingredient. See general definition of delayed release.
It is a sterile, lyophilized of liquid preparation, containing mainly IgG. Other proteins may also be
present.
Biological indicator
It is a preparation characterized by a specific microorganism that has defined and stable resistance to
a certain sterilization process.
Refractive index
The refractive index (n) of a substance is the ratio between the speed of light in a vacuum and its
speed inside the substance. For practical purposes refraction is measured with reference to air and
substance and not with reference to vacuum and substance. The refractive index can be defined as the
ratio between the sine of the angle of incidence and the sine of the angle of refraction, that is, n= sin
i / sin r.
Injectable
Insecticides
Products for external use, intended for the prevention and control of insects, in homes, enclosures and
places of public use and their surroundings.
Insulin
Insulin is a protein that affects glucose metabolism. It is obtained from the pancreas of healthy cattle
and pigs, or both, used as food by humans.
Human insulin
Human insulin is a protein corresponding to an active principle made in the human pancreas that
affects the metabolism of carbohydrates (particularly glucose), lipids and proteins.
Isophane human insulin suspension is a sterile suspension of human insulin crystals, zinc and
protamine sulfate in buffered water for injection, combined in such a manner that the solid phase of
the suspension is composed of human insulin crystals, protamine and zinc.
Isophane human insulin suspension and human insulin injection is a sterile buffered suspension of
human insulin, complexed with protamine sulfate, in human insulin solution.
It is a sterile suspension of human insulin in buffered water for injection, modified by the addition of
a suitable zinc salt so that the solid phase of the suspension is made up of a mixture of crystalline and
amorphous insulin in a ratio of about seven parts of crystals and three parts of amorphous material.
It is a sterile suspension of human insulin in buffered water for injection, modified by the addition of
a suitable zinc salt so that the solid phase of the suspension is predominantly crystalline.
Injectable Insulin
Insulin lispro
It is identical in structure to human insulin, except for the presence of lysine and proline at positions
28 and 29, respectively, of the B chain, while this sequence is inverted in human insulin. Insulin lispro
is produced by microbial synthesis through a recombinant DNA process.
It is an active chemical substance, medicine, drug or raw material that has pharmacological properties
with a medicinal purpose used for diagnosis, relief or treatment, used to modify or explore
physiological systems or pathological states for the benefit of the person to whom it is administered.
When intended for use in drugs, it must meet the requirements set in the individual monographs.
Insulators
Equipment that employs technology used for a dual purpose, to protect the product from
contamination by the environment and by people during filling and closure and to protect people from
toxic or harmful products that are produced.
Conventional release
It is the type of dosage form release that is not intentionally modified by a special formulation design
and/or manufacturing method.
Parametric release
It is defined as the release of cargo or batches of products subject to terminal sterilization, through
compliance with critical parameters of the sterilization process, without the need to perform a sterility
test.
Prolonged release
It is the type of modified release of pharmaceutical preparations that allows at least a reduction in the
dose frequency when compared to the drug presented in the conventional release form. It is obtained
through a special formulation design and/or manufacturing method.
Delayed release
It is the type of modified release of pharmaceutical preparations that has a delayed release of the
active ingredient. Delayed release is obtained through a special formulation design and/or
manufacturing method. Gastro-resistant preparations are considered delayed release forms, as they
are designed to resist gastric fluid and release the active ingredient into the intestinal fluid.
Extracting liquid
Lotion
It is an aqueous or hydroalcoholic liquid preparation, with variable viscosity, for application to the
skin, including the scalp. It can be a solution, emulsion or suspension containing one or more active
principles or adjuvants.
Batch or item
It is the quantity of a drug, or other product, that is produced in a manufacturing cycle and whose
essential characteristic is homogeneity.
Markers
Packaging material
By packaging material is understood the container; wrap; casing; or any other form of protection,
removable or not, used for filling; protect; keep; cover; or wrap, specifically or not, raw materials;
reagents and drugs.
Raw-materials
Active or inactive substances used in the manufacture of drugs and other products, both those that
remain unchanged and those subject to modification.
Media fill
It is a test for simulating aseptic operations in which the product is replaced by a culture medium and
serves to ensure that the processes used are capable of producing sterile products.
Drug
It is the pharmaceutical product, technically obtained or prepared, which contains one or more drugs
and other substances, with a prophylactic, curative, palliative or diagnostic purpose.
Reference drug
It is the innovative product registered with the Brazilian federal agency, responsible for sanitary
regulation and traded in the country, whose efficacy, safety and quality were scientifically proven by
the competent federal agency upon registration.
Generic drug
It is the drug similar to a reference or innovative product, intended to be interchangeable with this
product, usually produced after the expiration or waiver of patent protection or other exclusive rights,
proven its efficacy, safety and quality, and designated by the Brazilian Common Nomenclature
(DCB) or, in its absence, by the International Non-Proprietary Names (INN).
Interchangeable drug
It is the therapeutic equivalent of a reference drug, with essentially the same efficacy and safety
effects proven.
Compounded drug
It is any drug whose prescription details the composition, pharmaceutical preparation and dosage. It
is prepared in the pharmacy, by a qualified pharmaceutical professional or under his direct
supervision.
Pressurized drug
It is a pressure-packed drug containing a propellant gas and therapeutically active ingredients that are
released upon activation of an appropriate valve system.
Similar/Alternative drug
It is one that contains the same active principle(s), has the same concentration, pharmaceutical
preparation, route of administration, dosage and therapeutic indication, and which is equivalent to the
drug registered with the federal agency, responsible for health regulation, and may only differ in
characteristics regarding the size and shape of the product, expiration date, packaging, labeling,
excipients and vehicle, and must always be identified by trade name or brand.
Biological half-life
It is the time required for an organism to remove, by biological elimination, half the quantity of an
administered substance.
Effective half-life
It is the time it takes for a radionuclide in an organism to halve its activity as a combined result of
biological elimination and radioactive decay. The effective half-life is important for calculating the
optimal dose of the radiopharmaceutical to be administered and for monitoring the quantity of
radiation exposure.
Immunochemical methods
These methods are based on selective, reversible and non-covalent binding between antigens and
antibodies.
Miscibility
The term miscible is used to describe a liquid or gas that produces a homogeneous mixture when
mixed in any proportion with the indicated solvent in the same physical state.
Frozen or lyophilized, sterile, pyrogen-free preparation obtained from surplus human plasma from
donors having the same ABO and Rh(Du) blood group. The preparation is thawed or reconstituted
prior to use, in order to obtain an injectable solution. The human plasma used should meet the
requirements of the monograph Human Plasma for Fractionation.
It is the degree of guarantee that the process in question sterilizes a group of items, being expressed
as the probability of a non-sterile item in that population.
Chemical name
It is the name of the pharmacopoeial substance, according to the nomenclature recommended by the
International Union of Pure and Applied Chemistry (IUPAC).
Batch number
Designation printed on the labeling of a drug and other products that allows identifying the batch or
item to which they belong and, if necessary, locating and reviewing all manufacturing and inspection
operations carried out during production.
Nutrients
They are constituent substances of food with nutritional value, including proteins, fats, carbohydrates,
water, mineral elements and vitamins.
Fixed oil
They are non-volatile oils, liquid at room temperature. They are predominantly made up of
triacylglycerols, esterified with different or identical fatty acids.
Volatile Oil
Oils obtained from plants, by physical processes, which evaporate at room temperature without
leaving residue. They are made up of complex mixtures of low molecular weight substances which
determine their odor and taste. They can be presented alone or mixed with each other, rectified,
reduced or concentrated. They can also be called essential oils.
Oleoresin
They are semi-solid extracts consisting of a resin in solution in a volatile oil and/or fixed oil and are
obtained by evaporation of the solvent(s) used for their production. This definition applies only to
oleoresins produced by extraction.
Osmolality
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition GN-00
It is a practical form that gives a total measure of the contribution of various solutes in a solution by
the osmotic pressure of the solution. The osmolality unit is osmole per kilogram (osmole/kg), but the
submultiple milliosmole per kilogram (mosmole/kg) is normally used.
Ovule
It is a solid pharmaceutical preparation, with a single dose, containing one or more active ingredients
dispersed or dissolved in a suitable base which has several shapes, usually ovoid. They melt at body
temperature.
According to the WHO definition, pharmacopeial reference standards (PRef) are products of
recognized uniformity, intended for use in tests where one or more of their properties will be
compared with those of the substance under examination. They have a degree of purity suitable for
their intended use.
The PRef is established and distributed by pharmacopeial authorities, whose value attributed to one
or more of its properties is accepted without the need for comparison with another standard, intended
for use in specific tests described in pharmacopoeial monographs. They include reference chemical
substances, biological products, plant extracts and powders, radiopharmaceuticals, among others. The
most commonly used related expression is: Pharmacopoeia Reference Chemical Substance.
Paste
It is an ointment containing a large quantity of dispersed solids (not less than 25%). It must meet the
established specifications for ointments.
Losenge
It is a solid pharmaceutical preparation that contains one or more active ingredients, usually in a
sweetened and flavored base. It is used for slow dissolution or disintegration in the mouth. It can be
prepared by molding or by compression.
Hard losenge
Gummy losenge
Perfume
It is the aromatic composition product obtained from natural or synthetic substances, which, in
appropriate concentrations and vehicles, have as their main purpose scenting people or places,
including extracts, scented waters, creamy perfumes, bath preparations and ambient scents, presented
in liquid, gelled, creamy or solid form.
Industrial facility where atmospheric air is captured and, through processes of purification, cleaning,
compression, cooling, liquefaction and distillation, it is fractionated in order to obtain and isolate
oxygen, nitrogen and argon gases.
It is the remaining liquid part of a whole blood unit obtained after centrifugation and separation of its
cellular fractions, which must be completely frozen within four hours after collection of the whole
blood that originated it, ensuring the maintenance of the integrity and concentrations of labile
coagulation factors .
It is the remaining liquid part of whole blood after separation of blood cell fractions using appropriate
closed collection or centrifugation systems, which contains the labile coagulation factors. It contains
an anticoagulant, conservative and preservative solution and is stored at a temperature of -30°C or
lower. It is intended for the preparation of blood products in compliance with the Good Practices for
Drugs Manufacturing.
Powder
It is the solid pharmaceutical preparation containing one or more dry active ingredients and with
reduced particle size, with or without excipients
Aerosol powder
It is the pressure-packed powder containing a propellant gas and therapeutically active ingredients
that are released upon activation of an appropriate valve system.
Effervescent powder
It is the powder that contains, in addition to the active ingredients, acidic substances and carbonates
or bicarbonates, which release carbon dioxide when the powder is dissolved in water. It is intended
to be dissolved or dispersed in water prior to administration.
It is the sterile powder intended for the subsequent addition of liquid to form a solution. Prepared by
lyophilization, a process that involves removing water from products by congealing at extremely low
pressures.
It is the sterile powder intended for the subsequent addition of liquid to form a suspension. Prepared
by lyophilization, a process that involves removing water from products by congealing at extremely
low pressures.
It is the sterile powder intended for the subsequent addition of liquid to form a suspension. Prepared
by lyophilization, a process that involves removing water from products by congealing at extremely
low pressures. See general definition of prolonged release.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition GN-00
Mouthwash powder
It is the powder that must be dissolved in water to prepare the mouthwash, which is a liquid for mouth
rinsing that acts on the gums and mucous membranes of the mouth and throat. It must not be
swallowed.
It is the sterile powder intended for the subsequent addition of liquid to form a solution.
It is the sterile powder intended for reconstitution to form a solution for use by infusion. It is a sterile
solution, normally isotonic with blood and used primarily for large volume administration.
It is the sterile powder intended for the subsequent addition of liquid to form a suspension.
It is the sterile powder intended for the subsequent addition of liquid to form a suspension. See
definition of prolonged release.
Ointment
It is the semi-solid pharmaceutical preparation, for application to the skin or mucous membranes,
which consists of a solution or dispersion of one or more active ingredients in low proportions in a
suitable, usually non-aqueous base.
Expiry date
It is the time during which the product can be used, characterized as a useful life period and based on
specific stability studies. The expiry date must be indicated on the primary and secondary packaging.
When indicating month and year, the last day of that month is understood as the expiry date. The
storage and transport conditions specified by the manufacturer must be maintained.
It is the preparation intended for application to the skin or certain mucous membranes for local action
or percutaneous penetration of drugs, or for its emollient or protective action.
Herbal preparations
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition GN-00
They are homogeneous preparations, obtained from herbal drugs subjected to specific treatments,
such as extraction, distillation, expression, fractionation, purification, concentration or fermentation.
Examples of herbal preparations: extracts, oils, juice capsules, processed exudates and herbal drugs
that have been subject to size reduction for a specific application, for example, chopped herbal drugs
for making medicinal teas or powdered for encapsulation.
Aseptic process
Hygiene product
It is the product for external use; antiseptic or not; for cleaning or body disinfection, including soap,
shampoo, toothpaste, mouthwash, antiperspirant, deodorant, shaving and after-shave products,
astringent and others.
Dietary product
It is the product technically designed to meet the dietary needs of people with special physiological
conditions.
Semi-finished product
Purity
Off White
The term “almost white” is understood to be slightly grayish or yellowish, with a tendency to white.
It is the translation of the English term “off white”.
Rodenticide
It is the preparation intended to combat rats, mice and other rodents, in homes, boats, enclosures and
places of public use, containing active substances, isolated or in association, that do not pose a risk
to life or health of humans and useful warm-blooded animals, when applied in accordance with the
recommendations contained in its presentation.
They are reactions used to aid in the characterization of a substance. Although specific, they will only
be sufficient to establish or confirm the substance's identity when considered in conjunction with
other tests and specifications contained in the monograph. If the monograph does not specify
otherwise, chemical reactions are carried out in test tubes with approximately 15 mm in internal
diameter. Use 5 mL of the liquid or solution to be examined, adding three drops of reagent or of each
reagent. The examination of the contents of the test tube must be carried out over the entire liquid
layer, observing from top to bottom, in the direction of the longitudinal axis of the tubes, after five
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition GN-00
minutes of standing. Usually, the order of preference of identification tests is presented in the
monograph. When the order does not appear, all identification tests must be carried out.
It corresponds to the ratio between the amount of drug from natural origin used in the production of
an extract and the final quantity of extract, expressed in weight (w/w) or volume (w/v).
It corresponds to the ratio between the amount of herbal drug, expressed in mass, used in the
preparation of an extract, and the amount of the first extraction solvent, expressed in mass (w/w) or
volume (w/v).
It corresponds to the ratio between the amount of herbal drug used in the preparation of an extract
and the amount of native extract obtained. Thus, when there is no addition of adjuvants to a native
extract, EDR and EDR native must present the same values. On the other hand, the values observed for
EDR and EDRnative should be different in operations where adjuvants are added to the native extract.
Oleoresins are generally produced without the need for the addition of processing adjuvants, therefore
EDR and EDR native are generally identical. For soft and liquid extracts, for which the presence of
excipients or processing adjuvants is required, EDR and EDR native are identical (for example:
generally 20 to 30% of water in soft extracts and ethyl alcohol in tinctures).
Reagents
They are substances used in tests, reactions, assays and pharmacopoeial assays, either as such or in
solutions.
It is the one that protects its contents from loss and contamination by foreign solids, under the usual
conditions of handling, storage, distribution and transport.
Hermetic container
It is impermeable to air, or any other gas, under the usual conditions of handling, storage, distribution
and transport.
Opaque container
It is the one that prevents the visualization of the content, comprising all colors. It constitutes a light
protection barrier.
It is the hermetic container that contains a certain quantity of the drug intended to be administered
only once and that, once opened, cannot be closed with a guarantee of sterility.
Multi-dose container
It is the hermetic container that allows the removal of successive portions of its content, without
modifying the concentration, purity and sterility of the remaining portion.
It protects its contents from losses and contamination by foreign solids, liquids and foreign vapors,
efflorescence, deliquescence or evaporation under the usual conditions of handling, storage,
distribution and transport.
Translucent container
It is the one that allows the partial visualization of the content, comprising all colors except amber.
Transparent container
It is the one that allows the total visualization of the content, comprising all colors except amber.
Registration
It is the legal act that recognizes the adequacy of a product to health legislation, and its concession is
granted by Anvisa. It is a control carried out before marketing, being used in the case of products that
may present health risks. Products subject to sanitary regulation that are registered must meet the
criteria established by laws and specific regulations in order to minimize any potential risks that may
be related to the product.
It is the test that quantifies the intensity of the chemical reaction between water and the alkali elements
in the glass, especially sodium and potassium. This resistance determines the classification of the
glass type.
Label
It is the printed or lithographed identification, as well as the words painted or engraved with fire,
pressure or self-adhesive, applied directly on containers; casings; wraps; cartridges; or any other
packaging protector, external or internal, which cannot be removed or altered during the use of the
product and during its transportation or storage. Label manufacturing must comply with the
regulations in force by the federal Health Regulation agency.
Cleanrooms
Room in which the concentration of airborne particles is controlled. It is built and used in such a
manner as to minimize the introduction, generation and retention of particles within the room, in
which other relevant parameters such as temperature, humidity and pressure are controlled as
necessary.
Household sanitizer
Human blood
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition GN-00
It is a living tissue, circulating, connective, of a cellular, plasmatic and/or protein nature, contained
within the cardiovascular system, performing multiple and complex functions that ensure the
maintenance of life to the human body.
It is human whole blood in vitro from healthy donors collected in storing systems for the collection,
storage and processing of human blood containing anticoagulant and preservative solution.
System composed of equipment and tools that filters, retains moisture and concentrates oxygen from
the atmospheric air through the process of molecular adsorption. This system is also known as an
oxygen concentrator plant, Pressure Swing Adsorption (PSA).
Closed system
System for administering parenteral solutions that, throughout the preparation and administration,
does not allow the solution to come into contact with the environment.
Bottling systems for the collection, storage and processing of human blood or closed human blood
collection systems
They are containers or plastic bags, containing or not an anticoagulant, conservative and preservative
solution, intended for the collection, storage, fractionation and administration of human blood or
derivatives. They are non-toxic, sterile, non-pyrogenic and disposable, and can be manufactured from
one or several polymers, and depending on the case, from certain additives and are validated by their
respective analytical methods.
It is the liquid pharmaceutical preparation; clear and homogeneous, containing one or more active
ingredients dissolved in a suitable solvent or mixture of miscible solvents.
Colorimetric solution
It is the solution used as a colorimetric standard for comparison purposes. It is called “CS”.
Human albumin solution is a proteinaceous, sterile, pyrogen-free solution obtained from human
plasma that meets the requirements of the Human plasma for fractionation monograph.
Molal solution
It is the solution that contains one mole of solute per kilogram of solvent.
Molar solution
It is the solution that contains one mole of the solute in 1000 mL of the solution. The multiples and
submultiples of the molar solution are also designated by whole numbers or decimal fractions such
as: 2 M; M; 0,5 M; 0,1 M; etc.
Volumetric solution
It is the reagent solution, of known concentration, intended for use in quantitative determinations. In
FB 6 the concentrations of volumetric solutions are expressed in molarity. They are called “VS”.
They are solutions designed for the collection of human blood, aiming not only to make it
incoagulable, but also to ensure the maintenance and morphofunctional and protein integrity of its
cellular and plasmatic constituents.
Test solutions
They are indicator solutions in specific solvents and defined concentrations. They are called “TS”.
Reagent solutions
They are reagent solutions in specific solvents and defined concentrations. They are called “RS”.
Hyperimmune sera are preparations containing purified immunoglobulins of animal origin that
specifically neutralize bacterial toxins, bacteria, viruses or toxic components of the venom of one or
more species of venomous animals.
Adjuvant substance
It is the specific purpose substance added to injectable preparations. This substance must be selected
to increase the stability of the product; not cause interference with the therapeutic efficacy or with the
active ingredient assay; or cause toxicity in the dose administered to the patient. The adjuvant
substance can be solubilizing; antioxidant; chelating agent; buffer; antibacterial agent; antifungal
agent; antifoaming agent and others, when specified in the individual monograph. The presence of
the adjuvant substance must be clearly indicated on the labels of the primary and secondary
packaging, in which the product is delivered for consumption. If there is no express contraindication,
the air in the containers can be replaced by carbon dioxide or nitrogen. The addition of coloring
substance is not allowed.
The maximum limits for some adjuvants are listed below, if the monograph does not specify
otherwise:
a) for agents containing mercury or cationic surfactant compounds — 0.01%;
b) for chlorobutanol, cresol, and phenol-type agents — 0.5%;
c) for sulfur dioxide, or equivalent quantity of potassium or sodium sulfite, bisulfite or metabisulfite
— 0.2%.
CRS used in the absence of a Pharmacopeial CRS. This CRS must be characterized by means of
adequate tests and the values obtained must be properly documented.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition GN-00
It is established and made available by the Brazilian Pharmacopoeia Commission, following the
WHO principles, and made official by Anvisa, with its use mandatory throughout the national
territory. In the absence of a CRS-FB, the use of a CRS established by other recognized
pharmacopeias is allowed, in accordance with the legislation in force.
Standards for Atomic Absorption Spectrophotometry are identified by the name of the metal,
followed by the acronym RSA (Reagent Solution for Atomic Absorption).
Unsaponifiable substances
Unsaponifiable substances are those remaining from the saponification reaction, non-volatile at 100 –
105 °C and which were carried in the process of extracting the substance to be tested.
Suppository
It is a solid pharmaceutical preparation of various sizes and shapes adapted for introduction into the
rectal, vaginal or urethral orifice of the human body, containing one or more active principles
dissolved in a suitable base. They are usually absorbed, melt or dissolve at body temperature.
Suspension
It is the liquid pharmaceutical preparation that contains solid particles dispersed in a liquid vehicle,
in which the particles are not soluble.
Aerosol suspension
It is the liquid pharmaceutical preparation that contains solid particles dispersed in a liquid vehicle,
in which the particles are not soluble. See definition of prolonged release.
It is the liquid pharmaceutical preparation that contains solid particles dispersed in a liquid vehicle,
in which the particles are not soluble. See definition of delayed release.
Suspension drops
Injectable suspension
Spray Suspension
It is the suspension administered in the form of a liquid finely divided by a jet of air or steam.
Troche tablet
It is the solid pharmaceutical preparation prepared from a mass made with a hydroalcoholic solution,
the active ingredient and lactose, or from the grinding process moistened with a hydroalcoholic
solution. It is molded in tablet presses and is fragile and brittle.
Buffer
It is the preparation based on salts that are capable of supporting variations in the activity of hydrogen
ions.
Container, thermally insulated, suitable for storing medicinal gases in the form of cryogenic liquid.
Mobile container, thermally insulated, suitable for storing medicinal gases in the form of cryogenic
liquid.
The temperature or congealing point of a liquid or melted solid is the highest temperature at which it
solidifies. For pure substances that melt without decomposition, the liquid congealing point is equal
to its melting point.
The temperature or boiling point of a liquid is the corrected temperature at which the liquid boils
under a vapor pressure of 101.3 kPa (760 mm of Hg).
The temperature or melting point of a substance is the temperature at which it is completely melted.
Testing performed for safety reasons to ensure cylinders and tanks withstand the pressures for which
they were designed.
Tincture
It is the alcoholic or hydroalcoholic preparation resulting from the extraction of herbal drugs or from
the dilution of their extracts. They are obtained by liquid extraction using 1 part by mass of herbal
drug and 10 parts of extraction solvent, or 1 part by mass of herbal drug and 5 parts of extraction
solvent. The ratio can be in w/w or w/v. Alternatively, they can be obtained using either 1 part by
mass of herbal drug and sufficient quantity of extraction solvent to produce 10 parts by mass or
volume of tincture or 1 part by mass of herbal drug and sufficient quantity of extraction solvent to
produce 5 parts, by mass or volume, of tincture. Other proportions of herbal drug and extraction
solvent can be used. It is classified as simple or compound, as prepared with one or more herbal drugs.
Vaccines
Biological products that contain one or more antigenic substances that, when inoculated, are able to
induce specific active immunity and protect against disease caused by the infectious agent that
originated the antigen.
It is the time, in minutes, required to reduce the microbial population by 90% or a logarithmic cycle.
F-Value o
It is a measure of sterilizing effectiveness, that is, the number of minutes of thermal sterilization by
steam at a given temperature supplied to a container or product unit, at a given Z value.
Z-value
It is the temperature rise, in degrees, necessary to reduce the D-Value by 90% or to produce a
reduction of a logarithmic cycle in the thermal resistance curve.
Valve
Device capable of modifying the pressure or output (flow) of gases, or vacuum, either in the cylinder
or in the centralized gas system.
Valve that allows the passage of gas or provides vacuum in only one direction.
Routes of Administration
Viscosity
It is the expression of the resistance of liquids to flowing, that is, to the displacement of part of their
molecules on neighboring molecules. The viscosity of liquids comes from internal friction, that is,
from the forces of cohesion between molecules relatively close together. As temperature rises, the
average kinetic energy of the molecules increases, the amount of time the molecules spend together
decreases (on average), the intermolecular forces become less effective and the viscosity is lower.
The dynamic unit, in the CGS System, of viscosity is the poise. The CGS System of Units is a system
of physical measurement units, or dimensional system, of LMT typology (length, mass, time), whose
base units are the centimeter for length, gram for mass, and second for time .
Syrup
It is an oral solution characterized by high viscosity, conferred by the presence of sucrose or other
sugars or other thickening and sweetening agents in its composition. Syrups usually contain
authorized flavoring and/or coloring agents. When not intended for immediate consumption,
authorized antimicrobial preservatives must be added.
GENERAL INFORMATION
Water
The water mentioned in tests, reactions and tests is purified water. For injectable preparations, water
for injections, described in an individual monograph, should be used. When the use of carbon dioxide-
free water is prescribed, use purified water boiled for at least five minutes and protected from
atmospheric air during cooling and storage.
Volumetric instruments
Volumetric instruments are used to measure volume in tests, assays and pharmacopoeial assays, and
must be calibrated at a temperature of 25°C. If the volumetric instrument has not been calibrated at
25° C, the volume measurements must be carried out at the temperature indicated therein. In volume
measurements, the lower level of the meniscus of the liquid contained in volumetric devices must
touch the upper part of the reference line, with the line of sight in the same plane. In cases of strongly
colored or opaque liquids, the upper edge of the meniscus is used as a reference, in the horizontal
plane of vision. Volumetric devices for transferring liquids (pipettes or burettes), as they have been
gauged with water, will only be able to supply exactly the indicated volume when the liquids to be
measured have approximately the viscosity, surface tension and density of the water.
Conservation
Protecting from light means that the substance must be kept in an opaque container or capable of
preventing the action of light.
Protecting from dust means that the substance must be stored in a stoppered flask and wear protective
hood.
In the monograph, the temperature conditions under which the substance must be preserved can be
defined, using terms described below.
When it is necessary to keep a drug in a cool place, it can be kept in a refrigerator, if not indicated
differently in the individual monograph.
When conservation conditions are not specified in the monograph, they include protection against
humidity, congealing and excessive heat.
Substance description
Information relating to the description of a substance is generic and is intended for a preliminary
assessment of its integrity. The description itself is not indicative of purity and should be combined
with other pharmacopoeial tests to ensure that the substance complies with the monograph.
This expression means that drying must continue until two consecutive weighing do not differ by
more than 0.50mg per gram of the substance under examination, and the second weighing must be
carried out after an additional hour of drying under the specified conditions.
Desiccator
A desiccator is understood to be a container that can be perfectly closed, of adequate shape and
dimensions that allows maintaining an atmosphere of low humidity rate through desiccant agents
introduced in it, such as: silica gel, calcium chloride, phosphorus pentoxide, sulfuric acid, among
others.
Reduced pressure desiccator is what makes it possible to maintain an atmosphere of low humidity at
a reduced pressure of a maximum of 6.7 kPa (approximately 50mm of mercury), or at the pressure
indicated in the monograph.
When the result of a test or an assay is expressed in relation to the anhydrous or desiccated substance;
in relation to the substance; or any other specific basis, the determination of the water content or loss
on drying, or of another designated property, is carried out according to the method described in the
monograph of the respective substance, or according to that described on the labeling.
Identification tests
Identification tests make it possible to verify, with an acceptable level of certainty, that the identity
of the material under examination is in accordance with its packaging label. Although specific, they
are not necessarily sufficient to establish absolute proof of identity. However, failure to comply with
the requirements of an identification test can lead to errors in the material labeling. Other tests and
specifications in the monograph contribute to confirming the identity of the article under examination.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition GN-00
Some identification tests must be considered conclusive, such as: infrared, spectrophotometry with
specific absorption and high performance liquid chromatography coupled to spectrophotometry.
These tests must be carried out in addition to the counter ion test, when applicable.
Structure of monographs
The raw material monographs are identified by their Common Brazilian Denominations (DCB),
written in capital letters and centralized. Moreover, it is also comprised:
• whenever possible, the Latin name proposed by the INN – International Non-proprietary Names –
international generic names of the World Health Organization;
• the substance chemical structure;
• molecular formula followed by molar mass;
• the Common Brazilian Denomination and related number;
• chemical name, according to the ACS – American Chemical Society;
• CAS – Chemical Abstracts Service registration;
• Monograph text
The monographs of pharmaceutical preparations are identified by the name of the corresponding raw
material, followed by the name of the pharmaceutical preparation.
Expression of concentrations
Impurities
The tests described in the monographs limit the impurities to quantities that ensure the quality of the
drug. The fact that the trials do not include an infrequent impurity does not mean that it can be
tolerated.
This expression means that incineration must proceed at 800 ± 25 °C, or at another temperature
indicated in the monograph, until two consecutive weighing do not differ by more than 0.5mg per
gram of the substance under examination, and the second weighing must be carried out after fifteen
minutes of additional incineration.
The desired precision in tests, reactions and pharmacopoeial assays is indicated by the number of
decimals presented in the text. For example, the numeric value 20 indicates values not lower than
19.5 and no higher than 20.5; the numeric value 2.0 indicates values not lower than 1.95 and not
higher than 2.05; the numeric value 0.20 indicates values not lower than 0.195 and not higher than
0.205.
Tolerance limits, expressed numerically as a maximum and minimum value, indicate the purity of a
pharmacopoeial substance. These values can be expressed as percentage or absolute numbers.
The variation range must be strictly observed, and values outside the maximum and minimum limits
are not tolerated.
Pressure measurements
The expression pascal (Pa), used for pressure measurements such as arterial, atmospheric or internal
to a device, refers to the use of manometers or barometers calibrated in relation to the pressure exerted
by the force of one Newton uniformly distributed on a flat surface of 1 m 2 of area perpendicular to
the direction of the force; one pascal is equivalent to 7.5 × 10-3 mm of mercury.
When the hydration degree of pharmaceutical ingredients is not mentioned in the nomenclature, it is
an anhydrous substance.
Odor
The expressions: odorless; practically odorless; slight characteristic odor; or their variations, are
used by examining the sample after being exposed to air for fifteen minutes, when dealing with
packages of up to 25 g recently opened. In case of larger packages, transfer samples of approximately
25 g to a 100 mL capsule capacity.
The odor characterization is descriptive only and cannot be considered as a standard of purity, except
in cases where a particular, disallowed odor is indicated in the individual monograph.
Preparation of solutions
All solutions used in tests, assays and reactions are prepared with purified water, unless otherwise
indicated in the individual monograph.
The term recently prepared, referring to the preparation of solutions used in tests, assays and
reactions, indicates that the solution must be prepared, maximum, 24 hours before the assay is carried
out.
Reduced pressure
The term reduced pressure means pressure lower than or equal to 6.7 kPa (approximately 50 mm of
mercury), if not otherwise indicated in the monograph. When desiccation under reduced pressure on
desiccant agent is indicated in the monograph, the operation must be carried out under reduced
pressure in a desiccator or other suitable equipment.
Manufacturing processes
In the manufacture of injectable products, tablets, capsules or other pharmacopoeial preparations, the
use of adjuvant substances, described in the monographs and added for a specific purpose, is allowed.
They must be innocuous and must not have an adverse influence on the therapeutic efficacy of the
active substance contained in the preparation, nor interfere with tests and determinations. Whichever
method is used, the final product must correspond to the specifications included in the Brazilian
Pharmacopoeia, 6th edition.
Blank test
The terms: carry out blank parallel; carry out a blank test; or carry out a blank assay means repeating
the determination under identical conditions and with identical quantities of reagents, omitting only
the substance under examination.
Containers for injectable preparations must be made of materials that do not interact with the contents
and have sufficient transparency to allow visual inspection. The lids, when used, cannot influence the
drug composition or conservation, offering a perfect sealing, even after being perforated several
times. Containers for injectable preparations are classified into:
• single dose containers;
• multi-dose containers;
• infusion container.
Single dose containers, ampoules and cartridges for dental use are flasks made of glass or suitable
plastic material; closed by melting glass or with the use of fixed or movable plastic operculum. The
content should only be used in a single dose and cannot be reused.
Multi-dose containers are strong-walled glass flasks which, after being filled with liquid preparations
or with solids to be dissolved or suspended, are sealed with a lid of another material. The content of
these flasks can be removed for single or multiple dose administration.
Infusion containers are flasks with a capacity of more than 50 mL, and may reach 1000 mL, sealed
with a lid made of another material or not, made of glass or plastic. Medicines stored in these types
of containers must be administered in one go, using sterile equipment, and cannot contain bactericidal
or antifungal agents. The use of other types of adjuvants must be considered carefully.
Solubility
The indicated solubility should not be considered strictly as a physical constant, but as a complement
to other tests, and may have a definitive value when the substance does not present the minimum
solubility required, especially when the solvent is water.
The indications on the solubility to which reference is made are carried out at a temperature of 25 ±
5 ºC. The term parts refers to the number of milliliters of solvent per gram of solid to be dissolved.
The approximate solubilities established in the monographs are designated in descriptive terms,
whose meanings are listed in Table 1:
Temperature
All temperatures in FB 6 are expressed on the Celsius scale, and measurements are taken at 25°C,
except for density measurement and if not indicated differently in the individual monograph.
Units of measurement
The units included in the International System of Units (IS) are adopted in this Pharmacopoeia, as
listed in Annex B.
Aqueous vehicles
Water for injections is generally used as a vehicle for aqueous injectables. Sodium chloride solutions
or Ringer‘s solution or other suitable solutions, prepared with water for injections, may be used in
part or in whole rather than just water for injections, if monograph does not otherwise specify.
Non-aqueous vehicles
Non-aqueous vehicles used partially or fully to obtain injectable preparations can be miscible or
immiscible with water. Among water miscible vehicles, the most used are polyalcohols and ethylene
oxide polymers. Among those immiscible with water, the most used are fixed oils of vegetable origin
and mono- and diglycerides of fatty acids.
Fixed oils are odorless or almost odorless and their odor and taste should not resemble rancidity. They
must meet the requirements specified in the monographs and have the characteristics described below.
a) cooling test — transfer a quantity of fixed oil, previously desiccated at 105 ºC for two hours and
cooled at room temperature in a desiccator containing silica gel, to a colorless cylindrical glass
container, with an internal diameter of approximately 25 mm. Close the container and soak for
four hours in water maintained at 10°C. The liquid must remain clear enough so that a 0.5mm
thick black line can easily be seen when held vertically behind the cylinder and against a white
background;
b) Saponification value — between 185 and 200 (5.5.29.8);
c) iodine value — between 79 and 128 (5.5.29.10);
d) unsaponifiable substances — reflux 10 mL of the oil in water bath with 15 mL of sodium
hydroxide (1:16) and 30 mL of ethyl alcohol, shaking occasionally until the mixture becomes
clear. Transfer the mixture to a porcelain crucible, evaporate the ethyl alcohol in a water bath and
mix the residue with 100 mL of water. Solution must result;
e) free fatty acids — the free fatty acids in 10g of the oil should consume a maximum of 2 mL of
0.02 M sodium hydroxide.
Synthetic mono- or diglycerides of fatty acids must meet the following requirements:
a) they are liquid and remain clear when cooled to 10°C;
b) iodine value — not exceeding 140 (5.5.29.10).
Non-aqueous vehicles must be selected with special care, as they cannot be irritating, toxic or
sensitizing and must not interfere with the therapeutic efficacy of the preparation.
5 GENERAL METHODS
4B
For unit dose products, the test makes it possible to verify whether the units of the same batch have
uniform weight. To carry out the test, it is necessary to determine, in advance, the average weight of
the units in the batch.
Weigh 20 tablets individually and determine the average weight. A maximum of two units can be
tolerated outside the limits specified in Table 1, in relation to the average weight, however, none may
be above or below twice as much as the indicated percentages.
Weigh 20 sugar coated tablets individually and determine the average weight. A maximum of five
units can be tolerated outside the limits specified in Table 1, in relation to the average weight,
however, none can be above or below twice as much as the indicated percentages.
Hard capsules
Weigh 20 units individually, remove the contents of each one, clean properly and weigh again.
Determine the weight of the contents of each capsule by the difference in weight between the filled
and empty capsules. With the values obtained, determine the average weight of the content. Not more
than two units can be tolerated outside the limits specified in Table 1, in relation to the content
average weight, however, none may be above or below twice as much as the indicated percentages.
Soft capsules
Proceed as described for Hard capsules. To determine the average weight of the contents, cut the pre-
weighed capsules and wash them with ethyl ether or other suitable solvent. Place the casings exposed
to air, at room temperature, until the solvent has completely evaporated. Weigh again.
Weigh 20 suppositories or ovules individually and determine the average weight. A maximum of two
units can be tolerated outside the limits specified in Table 1, in relation to the average weight,
however, none may be above or below twice as much as the indicated percentages.
Carry out the test with 20 units. Remove metal seals in case of ampoule flasks. Remove labels that
could be damaged during testing. If necessary, dry the outer surface of the containers. Weigh the 20
units individually, with their respective lids. Remove the contents and wash the respective containers
using water and then ethyl alcohol. Dry in an oven at 105 ºC, for one hour, or at temperatures lower
than that, depending on the nature of the material, until constant weight. Cool to room temperature,
replace the lid and weigh again. The difference between the two weights represents the content
weight. Determine the average weight of the content of the 20 units. Not more than two units can be
tolerated outside the limits specified in Table 1, in relation to the content average weight, however,
none may be above or below twice as much as the indicated percentages.
Proceed as described for Sterile powders, lyophilized powders and powders for injectables. Not more
than two units can be tolerated outside the limits specified in Table 1, in relation to the content
average weight, however, none may be above or below twice as much as the indicated percentages.
Table 1 – Evaluation criteria for determination of weight for pharmaceutical preparations in unit dose.
Variation
Pharmaceutical preparations in unit dose Average weight
limits
Uncoated or film-coated tablets, effervescent 80mg or less more than ± 10.0%
tablets, sublingual tablets, vaginal tablets and 80mg and less than 250mg ± 7.5
lozenges 250mg or more ± 5.0
25 mg or less ± 15.0%
more than 25mg and up to 150mg ± 10.0%
Sugar coated tablets (dragees)
more than 150mg and less than 300mg ± 7.5
300mg or more ± 5.0
less than 300 mg ± 10.0%
Hard and soft capsules, vaginal capsules
300mg or more ± 7.5
Suppositories and ovules Independent of average weight ± 5.0
Sterile powders, lyophilized powders and
more than 40mg* ± 10.0%
powders for injectables
less than 300 mg ± 10.0%
Powders for reconstitution (oral use)
300mg or more ± 7.5%
__________
(*) If the average weight is 40mg or less, submit to the Uniformity test of unit doses (5.1.6).
For products packed in containers for multiple doses, the test allows checking the homogeneity of the
filling.
Weigh 10 units individually. Remove the contents and wash the respective containers using adequate
solvent. Dry, cool to room temperature and weigh again. The difference between the two weights
represents the content weight.
Determine the average weight of the content of the 10 units. Individual values do not differ by ±10%
from the average weight.
Note: to carry out the test, it is necessary to know the filling nominal quantity.
Weigh 10 units individually. Remove the contents and wash the respective containers using adequate
solvent. Dry, cool to room temperature and weigh again. The difference between the two weights
represents the content weight.
Determine the average weight of the content of the 10 units. The average weight of the contents is
not inferior to the declared weight and the individual weight of none of the units tested is inferior to
the percentage indicated in Table 2, in relation to the declared weight.
If this requirement is not met, determine the individual weight of the content of 20 additional units.
The average weight of the 30 contents is not inferior to the declared weight and the individual weight
of not more than one unit in 30 is inferior to the percentage indicated in Table 2, in relation to the
declared weight.
Table 2 – Evaluation criteria for determination of weight for pharmaceutical preparations in multi-doses.
Minimum percentage in
Pharmaceutical forms in multi-doses Declared weight relation to the declared
weight
up to 60 g 90.0
Granules, powders, gels, creams and
above 60 g and up to 150 g 92.5
ointments
above 150.0 g 95.0
PROCEDURE
Separate 10 units Remove metal seals, when applicable. Remove labels that could be damaged during
testing. Weigh each container with their respective lids individually. Homogenize, remove and
combine the contents and reserve for determination of mass density. Wash containers and lids with
water and then with ethyl alcohol. Dry in an oven at 105 ºC, for one hour, or at a temperature
compatible with the container material, until constant weight. Cool to room temperature, replace the
lid and further corresponding parts and weigh again.
The difference between the two weights represents the content weight. Determine the corresponding
individual volumes (V), in mL, using the expression:
𝑚
𝑉=
𝜌
where
m = content weight, in g;
ρ = mass density of the product, in g/mL, determined at 20 ºC, as described in Determination of mass
density and relative density (5.2.5).
From the values obtained, calculate the average volume of the units tested. The average volume is
not inferior to the declared volume and the individual volume of none of the units tested is inferior to
95.0% of the declared volume.
Liquid products in multi-dose containers obtained from powders for reconstitution (except
injectables)
Separate 10 units Reconstitute each unit as indicated on the label. Proceed as described in Liquid
products in multi-dose containers (except injectables)
From the values obtained, calculate the average volume of the units tested. The average volume is
not lower than the declared volume and the individual volume of none of the units tested is lower
than 95.0% or greater than 110.0% of the declared volume.
Separate 10 units Pour, separately, the content of each unit into calibrated dry graduated cylinders
with a capacity that does not exceed 2.5 times the volume to be measured, taking precautions to avoid
the formation of bubbles. Allow the liquid to drain for five seconds, unless otherwise indicated in the
individual monograph. Carry out the measurement.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.1.2-00
From the values obtained, calculate the average volume of the units tested. The average volume is
not lower than the declared volume and the individual volume of none of the units tested is lower
than 95.0% or greater than 110.0% of the declared volume.
The test applies to liquid injectable products packaged in containers such as ampoules, vials, plastic
bags, plastic vials, carpule syringes or pre-filled syringes. The containers are filled with a small excess
of volume, according to the product features, to allow the administration of the declared volume. The
minimum volume excesses recommended in Table 1 are generally sufficient to allow the removal
and administration of the declared volume.
Suspensions and emulsions must be agitated before removing the content and before determination
of density. Oily or highly viscous preparations can be heated, if necessary, as indicated on the label
or to a maximum of 37°C, and shaken vigorously before removing the content. The contents are then
cooled to between 20°C and 25°C before volume measurement.
For injectables in single-dose containers, test six units if the declared volume is equal to or greater
than 10 mL, 10 units if the declared volume is greater than 3mL and less than 10mL, or 12 units if
the declared volume is equal to or less than 3 mL. Remove the total contents of each unit with the aid
of a syringe with a capacity that does not exceed three times the volume to be measured, fitted with
a number 21 needle and not less than 2.5 cm long. Eliminate any bubbles that may exist in the needle
and syringe and transfer the contents of the syringe, without emptying the needle, to a dry, calibrated
measuring cylinder with a capacity not exceeding 2.5 times the volume to be measured. Alternatively,
the contents of the syringe can be transferred to a dry tared graduated beaker, the volume being
calculated by the weight of the liquid, in g, divided by its density. For containers with a declared
volume of 2 mL or less, the contents of the containers can be collected to obtain the volume required
for the assay, using separate dry syringes and needles for each container. The contents of containers
with a declared volume of 10 mL or more can be determined by emptying the contents of each
container directly into calibrated measuring cylinders or tared beakers.
The volume of each container examined is not inferior to the declared volume. In the case of
containers with a declared volume of 2 mL or less, the volume of the collected contents is not inferior
to the sum of the declared volumes of the containers used in the test.
For injectables in multi-dose containers labeled to contain a specific number of doses of a given
volume, select a unit and proceed as described for injectables in single-dose containers, using the
number of separate syringes and needles equivalent to the number of doses specified on the label .
The volume dispensed by each syringe is not inferior to the declared volume per dose.
For injectables in cartridges or pre-filled syringes, test one unit if the declared volume is equal to or
greater than 10 mL, three units if the declared volume is greater than 3 mL and less than 10 mL, or
five units if the declared volume is equal or less than 3 mL. Adjust the necessary tools to the
containers for their use (needle, plunger, syringe body), when applicable, and transfer the content of
each container, without emptying the needle, to a tared dry graduated beaker, pushing the plunger
slowly and regularly. Calculate the volume, in milliliters, by dividing the liquid weight, in g, by its
density. The volume of each container is not inferior to the declared volume.
For large volume injectable preparations (parenteral infusions), select two units and transfer the
content of each container to calibrated dry measuring cylinders with a capacity that does not exceed
2.5 times the volume to be measured. The volume of each container is not inferior to the declared
volume.
The test applies mainly to uncoated tablets. The test consists of submitting the tablet to the action of
a device that measures the force, applied diametrically, necessary to crush it. Force is measured in
newtons (N).
APPARATUS
Different types of apparatus can be used, which basically differ in the mechanism used to exert
pressure. Force can be exerted manually or mechanically. As the pressure increases, a plunger, plate
or piston applies a certain force on the tablet, supported by a fixed base. The apparatus is calibrated
to a 1 N accuracy.
PROCEDURE
The test is carried out with 10 tablets, eliminating any surface residue before each determination. The
tablets are individually tested, always following the same orientation (consider the shape, presence
of groove and engraving). Express the result as the average of the values obtained in the
determinations. The test result is informative.
The friability test makes it possible to determine the tablets strength to abrasion, when subject to the
mechanical action of a specific apparatus. The test applies solely to uncoated tablets.
The test consists of accurately weighing a determined number of tablets, submitting them to the action
of the apparatus and removing after 100 rotations. After removing any powder residue from the
tablets, they are weighed again. The difference between the initial and final weight represents the
friability, measured from the percentage of powder lost.
APPARATUS
The apparatus (Figure 1) consists of a rotating cylinder, with (287.0 ± 4.0) mm in diameter and
(38.0 ±2.0) mm in depth, made of transparent synthetic polymer with polished internal faces, of low
static activity, which rotates around its axis at a speed of (25 ± 1) revolutions per minute. One of the
cylinder faces is removable. The tablets are collected at each turn of the cylinder by a curved
projection with an inner radius of (80.5 ± 5.0) mm that extends from the center to the outer wall of
the cylinder, and taken to a height of (156.0 ± 2.0) mm, from which they fall repeatedly.
10.0 ± 0.1 mm
156.0 ± 2.0 mm diameter
fall height 287.0 ± 4.0 mm
internal diameter
80.5 ± 5.0 mm
internal radius
25.0 ± 0.5 mm
diameter
38.0 ± 2.0 mm
Figure 1 - Apparatus for friability test (friabilometer).
PROCEDURE
For tablets with an average weight equal to or less than 0.65 g, use 20 tablets. For tablets with an
average weight greater than 0.65 g, use 10 tablets. Accurately weigh the tablets and place them in the
apparatus. Set speed to 25 revolutions per minute and test time to four minutes. When time elapsed,
remove any residue of powder from the surface of the tablets and weigh again. No tablet may be
broken, chipped, cracked or split at the end of the test. Tablets with a loss equal to or less than 1.5%
of their weight or the percentage established in the monograph are considered acceptable. If the result
is doubtful or if the loss is greater than the specified limit, repeat the test twice more, considering, in
the evaluation, the average result of the three determinations.
The test applies to uncoated, film-coated or sugar-coated tablets (dragees), enteric-coated tablets,
sublingual tablets, soluble tablets, dispersible tablets, hard capsules and soft capsules It can be applied
to chewable tablets; in this case, the conditions and evaluation criteria will appear in the individual
monograph. The test does not apply to losenges and tablets or controlled (prolonged) release capsules.
Disintegration is defined, for the purposes of this test, as the state in which no residue from the tested
units (capsules or tablets) remains on the wire mesh of the disintegration apparatus, except for
insoluble fragments of tablet coatings or capsule shells. Units that turn into a creamy mass during the
test are also considered as disintegrated, as long as they do not present a palpable core.
APPARATUS
It consists of a system of baskets and tubes (Figure 1), a suitable container for the immersion liquid
(a graduated beaker with a capacity of 1 liter), a thermostat to keep the liquid at (37 ± 1) °C and a
mechanism to move the basket and tubes in the immersion liquid, with constant frequency and
specific path. The volume of the immersion liquid must be sufficient so that, when reaching the
highest point of the route, the bottom of the basket is at least 25 mm below the surface of the liquid,
and that at the lowest point it is at least 25mm from the bottom of the beaker. Upward and downward
movements should have the same speed and the change in direction of movement should be smooth.
The basket consists of six tubes of clear glass or acrylic, open on both sides. The dimensions of the
tubes are: length (77.5 ± 2.5) mm, internal diameter between 20.7 mm and 23.0 mm, and wall
thickness of approximately 2 mm.
The tubes are kept vertically, adapting at each end of the basket a disk of suitable transparent material,
with a diameter between 88.0 mm and 92.0 mm and thickness between 5.0 mm and 8.5 mm, having
six holes in which the tubes are introduced. The six holes are equidistant from the center of each disc,
being equally spaced. On the external face of the lower disc is a stainless-steel wire mesh (wire
diameter of (0.635 ± 0.030) mm, with an opening between 1.8mm and 2.2mm, attached to the disc
by three screws.
For capsule disintegration testing, a stainless steel wire mesh, similar to the one fitted to the basket
lower disc, or other suitable device can be fitted to the external face of the upper disc to prevent the
capsules from escaping from the tubes during testing.
The parts that constitute the basket are assembled and held firmly together by a central metal axis,
with a diameter of about 5mm. The upper end of the central axis must have a device to attach the
basket to the mechanism that produces the vertical movement of the system.
When indicated, a cylindrical disc of suitable transparent material must be added to each tube of the
basket, with a relative density between 1.18 and 1.20, diameter of (20.70 ± 0.15) mm, and thickness
of (9.50 ± 0.15) mm. Each disc has five holes, each of 2mm in diameter, with one hole on the cylinder
axis and the other four equidistant, arranged on a circle with a radius of 6mm relative to the center of
the disc. The lateral surface of the disc has four equidistant dents, with a depth of (2.6 ± 0.1) mm, in
a V shape, which, on the upper side of the disc, measure (9.4 ±0.2) mm of width, and 1.6mm.on the
lower side. All disc surfaces are smooth. Basket design and assembly may vary as long as
specifications for tubes and mesh opening are maintained.
Stainless
steel wire
mesh
Figure 1 – Apparatus for tablet and capsule disintegration test (dimensions in mm).
PROCEDURE
Uncoated tablets
Use six tablets in the test. Place a tablet in each of the six tubes of the basket, add a disk to each tube
and activate the apparatus, using water maintained at (37 ± 1) °C as immersion liquid, unless another
liquid is specified in the medication monograph. At the end of the specified time range, stop the
movement of the basket and observe the material in each of the tubes. All tablets must be fully
disintegrated. If tablets do not disintegrate due to sticking to the discs, repeat the test with six other
tablets, omitting the discs. All tablets must be fully disintegrated upon test completion. The time limit
established as a general criterion for disintegration of uncoated tablets is 30 minutes, unless otherwise
indicated in the individual monograph.
Use six tablets in the test. Place one tablet in each one of the six tubes in the basket. Place a disk in
each tube and activate the apparatus, using water maintained at (37 ± 1) °C as immersion liquid. At
the end of the specified time range, stop the movement of the basket and observe the material in each
of the tubes. If the tablets are not fully disintegrated, test another six tablets using 0.1 M hydrochloric
acid, kept at (37 ± 1) °C, as immersion liquid. At the end of the specified time range, stop the
movement of the basket and observe the material in each of the tubes. All tablets must be fully
disintegrated. If tablets do not disintegrate due to sticking to the discs, repeat the test with six other
tablets, omitting the discs. All tablets must be fully disintegrated upon test completion. The time limit
established as a general criterion for disintegration of film-coated tablets is 30 minutes, and for sugar-
coated tablets (dragees), 60 minutes, unless otherwise indicated in the individual monograph.
Use six units in the test. Place one unit in each one of the six tubes in the basket. Activate the
apparatus, without adding the discs, using 0.1 M hydrochloric acid, kept at (37 ± 1) °C, as immersion
liquid, for 60 minutes or for the time specified in the individual monograph. Cease basket movement
and observe the tablets or capsules. No unit may show any sign of disintegration, cracking or softening
that could allow its content to leak out. Use phosphate buffer solution pH 6.8, kept at (37 ± 1) °C, as
immersion liquid. Place a disk in each tube and turn on the apparatus. After 45 minutes or the time
specified in the monograph, cease basket movement and observe the material in each tube. All tablets
or capsules must be completely disintegrated and only insoluble coating fragments may remain. If the
tablets or capsules do not disintegrate due to sticking to the discs, repeat the test with six other units,
omitting the discs. All tablets or capsules must be fully disintegrated at the end of the test. The test
does not apply to uncoated capsules containing an enteric release preparation.
Sublingual tablets
Carry out the test as described for Uncoated Tablets, omitting the use of discs. All tablets must be
fully disintegrated after five minutes.
Carry out the test as described for Uncoated Tablets, using water kept between 15°C and 25°C as
immersion liquid. All tablets must be fully disintegrated after three minutes.
Carry out the test as described for Uncoated Tablets, omitting the use of discs. Use a mesh with an
opening of 1.8 mm to 2.2 mm, made of stainless-steel wire adapted to the external face of the upper
disc, as described in the item Apparatus. Observe capsules after 45 minutes or as specified in the drug
monograph. All capsules must be fully disintegrated, or only insoluble fragments of soft consistency
remain on the mesh.
Soft capsules
Carry out the test as described for Uncoated Tablets, using the discs. Observe capsules after 30
minutes or as specified in the drug monograph. All capsules must be fully disintegrated, or only
insoluble fragments of soft consistency remain on the mesh. If the capsules do not disintegrate due to
sticking to the discs, repeat the test with six other units, omitting the discs. All capsules must be fully
disintegrated at the end of the test.
APPARATUS
The apparatus (Figure 1) consists of a transparent glass or plastic cylinder, with walls of appropriate
thickness, inside which is attached, by three metal hooks, a metallic device consisting of two
perforated stainless steel discs, each containing one 39 orifices of 4 mm in diameter each. The
diameter of each disc is such that it can be inserted into the transparent cylinder, with the discs being
spaced approximately 30 cm apart. The determination is carried out using three devices, each
containing a single sample. Each apparatus is placed inside a beaker of not less than 4 liters of
capacity, containing water at a temperature of 36°C to 37°C, unless otherwise indicated in the
individual monograph. The beaker is equipped with a stirrer that operates at a slow speed and a device
that allows the cylinder to be inverted without removing it from the water.
PROCEDURE
Use three suppositories or ovules. Place each one on the device's lower disk and insert and fix the
disk inside the cylinder. Invert the device every 10 minutes. Examine the samples after the time
prescribed in the monograph has elapsed. The test is considered satisfactory if all samples are
disintegrated. The time limit established as general criteria for disintegration is 30 minutes for
suppositories, ovules and vaginal tablets with a hydrophobic base, and 60 minutes for suppositories
with a hydrophilic base, unless otherwise indicated in the individual monograph.
Vaginal tablets
Use the device described in Disintegration of suppositories and ovules, assembled as shown in Figure
2. Introduce the cylinder into a beaker of a suitable diameter containing water between 36°C and
37°C, which should evenly cover the perforations of the disc. Use three devices, placing a vaginal
tablet on the upper disc in each one. Cover the device with a glass plate to ensure adequate humidity.
Examine each sample after the time prescribed in the monograph has elapsed. The test is considered
satisfactory if all samples are disintegrated.
A, glass plate; B, vaginal tablet; C, water surface; D, water; E, bottom of the container.
The dissolution test makes it possible to determine the quantity of active substance dissolved in the
dissolution medium when the product is subject to the action of a specific apparatus, under described
experimental conditions. The result is expressed as a percentage of the quantity stated on the label.
This test is used to demonstrate whether the product meets the requirements in the drug monograph
in tablets, capsules and other cases where testing is required.
(1) Open containers in a cylindrical shape and hemispherical bottom (vats), made of boron silicate
glass, plastic or other transparent and inert material, to which an inert material lid can be adapted,
with suitable openings for the stirrer, sample collection and thermometer insert. The tanks can have
the following dimensions and capacities: (185 ± 25) mm in height and (102 ±4) mm in internal
diameter for a nominal capacity of one liter; (290 ± 10) mm in height and (102 ±4) mm in internal
diameter for a nominal capacity of two liters; (290 ± 10) mm high and (150 ± 5) mm inside diameter
for a nominal capacity of four liters.
(2) Stainless steel rods to provide agitation of the medium, which can be presented in two forms:
baskets (Method 1) or paddles (Method 2) (Figures 1 and 2). The rod must be centered in such a
manner that, when activated, its rotation axis does not distance more than 2 mm in relation to the
vertical axis of the container containing the dissolution medium.
(3) A motor that makes it possible to adjust the rotation speed of the rod to that specified in the
individual monograph, keeping it within the limits of ± 4%. The rotation must not pose undesirable
effects on the hydrodynamics of the system.
The tanks are immersed in a thermostatic water bath, of transparent material and adequate size, in
which the temperature is maintained at (37 ± 0.5) °C while carrying out the test. The device must be
free from any source of vibration, including external ones, that could influence the hydrodynamics of
the system. Preferably, the device should allow the visualization of samples and shakers during the
test.
Method 1: Baskets
When specified in the monograph, a stainless-steel rod is used as a stirrer, at the end of which a basket
of the same material is fitted (Figure 1). The standard mesh used in making the basket has a wire
diameter of 0.25 mm and a square mesh opening of (0.40 ±0.04) mm (40 mesh), unless otherwise
specified in the individual monograph. The sample must be placed in the dry basket before starting
the test. During its execution, a distance of (25 ± 2) mm must be maintained between the bottom of
the basket and the inner bottom of the container containing the dissolution medium.
Rotation axis
Figure 1 - Method 1 (Baskets). The basket and the tank are not in the same size proportion.
Method 2: Paddles
When specified in the monograph, a stainless-steel rod is used as a stirrer, coated or not with inert
material, whose end has the shape of a paddle (Figure 2), capable of rotating smoothly and without
axis deviation for the specified time and speed in the corresponding monograph. The sample should
be added, whenever possible, before starting the test. During its execution, a distance of (25 ± 2) mm
must be maintained between the bottom of the paddles and the inner bottom of the container
containing the dissolution medium.
It is important that samples do not float in the dissolution medium. An appropriate device can be used,
made of spiral steel wire in a few turns and with a sufficient diameter to trap the capsule or tablet
without deforming them or reducing the area of contact with the medium.
Rotation axis
9.4 mm to 10.1 mm
Dissolving medium
level
Approximate
location of
Radius: 41.5 mm
sample
collection
74.0 to 75.0 mm
Figure 2 - Method 2 (Paddles). The paddle and the tank are not in the same size promotion.
The dissolution apparatus for Method 3 consists of a series of flat-bottomed cylindrical vials; a series
of glass cylinders with a closing system made of inert material (stainless steel or other suitable
material) and meshes made of non-adsorbent and non-reactive material, designed to be attached to
the upper and lower parts of the cylinders. A motor and a cylinder fitting device must allow vertical
alternating movement, ascending and descending, of the cylinders in the flasks and, also, providing
horizontal displacement of the cylinder to another flask arranged in a different row.
The vials remain partially immersed in a water bath, of adequate dimensions, which allows
thermostatization at (37 ± 0.5) °C during the test period. The device must be free of any vibration,
internal or external, that could influence the smooth upward and downward movement of the
cylinders. The apparatus must have a device for adjusting the speed of alternating movement, as
recommended in the individual monograph, with a maximum variation of ± 5%.
Preferably, the device should enable the visualization of the cylinders and samples under analysis
inside. The flasks must have a suitable stopper which must remain fixed during the test. The assembly
components have the dimensions shown in Figure 3, unless there is some differentiate specification
in the monograph.
Orifices
Flask cap
Orifices
Perforated mesh
Gas cylinder
Perforated mesh
Glass flask
DISSOLUTION MEDIUM
The dissolution medium specified in the product monograph is used, previously degassed by a
convenient procedure, when necessary, to avoid the formation of bubbles that could interfere with the
dissolution speed of the pharmaceutical preparation. When the dissolution medium is a buffer
solution, the pH should be adjusted to ± 0.05 units of the pH value specified in the product
monograph.
DISSOLUTION TIME
When a single time is specified in the product monograph, it represents the maximum time within
which the minimum quantity, in percentage, of active substance established must be dissolved. When
more than one time is specified in the monograph, appropriately measured aliquots must be taken at
the end of each time indicated.
Assemble and check the apparatus according to the specifications previously mentioned in order to
reduce, to a minimum, factors that significantly change the hydrodynamics of the system (axis
deviation, vibration, etc.). Add the measured volume of the Dissolution Medium specified in the
product monograph, suitably degassed, if necessary, to the dissolution apparatus container. Keep the
temperature of the medium at (37 ± 0.5) °C, removing the thermometer before starting to agitate. In
Method 1, place the sample into the dry basket. In Method 2, place the sample into the dissolution
container as described above. In both cases, upon observing the formation of bubbles on the surface
of the samples, when in contact with the dissolution medium, check their influence on the result.
Immediately start agitating, according to the pre-set speed. At the time range(s) specified in the
product monograph, remove an aliquot for analysis of the intermediate region between the surface of
the dissolution medium and the top of the basket or paddles, at least 1 cm from the inner wall of the
container ( Figures 1 and 2). While removing the aliquot, keep shaking. Immediately filter the
samples, if not using filters coupled to the sampling system. The filters used must be inert, not adsorb
a significant portion of the drug and have adequate porosity. As specified in the product monograph,
the sample volume taken may or may not be replaced. If replacement is necessary, the same
dissolution medium heated to 37 °C should be used. If the replacement of the dissolution medium is
not carried out, correct the volume in the calculations. After filtration and dilution (when necessary)
of the aliquot, the drug is quantified using the method indicated in the product monograph. Repeat
the test with additional unit doses as necessary considering the Acceptance Criteria.
Dissolution of capsules: if the result is unsatisfactory, repeat the test as follows: when the dissolution
medium is water or buffer with a pH lower than 6.8, use the same specified dissolution medium with
addition of purified pepsin with activity of not more than 750 000 units/1000 mL.
For dissolution media with a pH equal to or greater than 6.8, add pancreatin with an activity of not
more than 1750 protease units/1000 mL.
Method A
Acid stage: use 750 mL of 0.1 M HCl as Dissolution Medium in the tanks when using Methods 1 and
2. Assemble the dissolution apparatus as described in Apparatus for Methods 1 and 2 and add a test
unit to each tank or basket, as appropriate. Carry out the test at the speed specified in the monograph
for two hours. At the end of this period, remove an aliquot from the Dissolution Medium and
immediately carry out Buffer Stage pH 6.8. Determine the amount of drug dissolved in the sampled
aliquot, using appropriate analytical method.
Buffer stage pH 6.8: carry out the preparation of the buffer stage and pH adjustment in five minutes.
With the dissolution apparatus operating at the speed specified for the product, add 250 mL of 0.20
M sodium phosphate tribasic solution, previously heated to (37 ± 0.5) °C, to the Acid Stage
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.1.5-00
Dissolution Medium. If necessary, adjust pH to (6.8 ± 0.05) with 2 M HCl or 2 M NaOH. Continue
operating the dissolution apparatus for 45 minutes or for the time specified in the monograph. At the
end of this period, remove an aliquot from the Buffer Stage Dissolution Medium pH 6.8 and determine
the amount of drug dissolved, using appropriate analytical method.
Method B
Acid stage: use 1000 mL of 0.1 M HCl as Dissolution Medium in the tanks and assemble the
dissolution device as described in Apparatus for Methods 1 and 2. Add a test unit to each tank or
basket, as appropriate. Carry out the test at the speed specified in the monograph for two hours. Time
elapsed, remove an aliquot of the Dissolution Medium and immediately carry out Buffer Stage pH
6.8. Determine the amount of drug dissolved in the sampled aliquot, using appropriate analytical
method.
Buffer stage pH 6.8: use phosphate buffer pH 6.8, previously heated to (37 ± 0.5) °C. Drain the Acid
Stage dissolution medium from the tanks and add 1000 mL of pH 6.8 phosphate buffer dissolution
medium. Alternatively, each tank with the Acid Stage medium can be removed from the dissolution
apparatus and replaced by another tank with pH 6.8 Stage buffer medium, carefully transferring the
test unit of the drug under test. Continue operating the dissolution apparatus for 45 minutes or for the
time specified in the monograph. At the end of this period, remove an aliquot from the Buffer Stage
pH 6.8 dissolution medium and determine the amount of drug dissolved, using appropriate analytical
method. The pH 6.8 buffer can be prepared by mixing three volumes of 0.1 M HCl and one volume
of 0.20 M sodium phosphate tribasic solution, if necessary adjusting the pH to 6.8 ± 0.05 with 2 M
HCl or 2 M NaOH.
Immediate release dosage forms: using Method 3, add the volume of Dissolution medium specified
in the product monograph to each flask of the device, place the flasks in the bath instrument to
acclimatize to (37 ± 0.5) °C and remove the thermometers before starting the test. Place a sample
dosage unit in each of the six alternating cylinders, avoiding the formation of air bubbles on the
surface of the material, and immediately start operating the device as specified in the individual
product monograph. During the upward and downward movement of the cylinders, the height range
should be between 9.9 and 10.1 cm. At the time range(s) specified in the individual monograph, lift
the cylinders and sample an aliquot of the Dissolution Medium from each vial, from the intermediate
region between the liquid surface and the bottom of the vial. After filtering and diluting (when
necessary) the aliquot, carry out a quantitative analysis of the dissolved drug according to what is
recommended in the individual product monograph. If necessary, repeat the test with additional units
of drug. Replace the volume of sampled medium with an equal volume of freshly prepared
Dissolution Medium maintained at (37 ± 0.5) °C or, in situations where it is proven that it is not
necessary to replace the medium, correct the volume change during the calculations . Keep the vials
covered with their respective caps during the test and periodically check the temperature of the
medium. For the medium and dissolution time, follow the general guidelines indicated in Dissolution
Medium and Dissolution Time.
Prolonged-release dosage forms: using Method 3, perform the procedure as described in Immediate-
release dosage forms and follow the general guidelines indicated in Dissolution Medium and
Dissolution Time . Times are expressed in hours and normally at least 3 time ranges are indicated.
Delayed release dosage forms: using Method 3, based on the procedure indicated in Method B for
Delayed release dosage forms, using a row of vials for the Acid stage and the successive row of vials
for the stage with buffer solution pH 6 .8, adding the volume of medium specified in the monograph
(usually 300 mL). Collection times are those specified in the monograph or the general ones indicated
in Method B for Delayed Release Dosage Forms.
The product complies with the test if the results meet the requirements described in Table 1, unless
otherwise specified in the individual monograph.
Table 1 – Acceptance criteria for the dissolution test of immediate release dosage forms.
Number of samples
Stages Acceptance criteria
tested
E1 06 Each unit has a result greater than or equal to Q + 5%.
Average of 12 units (E1 + E2) is equal to or greater than Q and no unit has
E2 06
a result lower than Q – 15%.
Average of 24 units (E1 + E2 + E3) is equal to or greater than Q, at most
E3 12 two units have results less than Q – 15% and no unit has results less than
Q – 25%.
The term Q corresponds to the quantity of dissolved drug, specified in the individual monograph,
expressed as a percentage of the declared quantity. The 5%, 15% and 25% values also represent
percentage of the declared quantity.
Stage E1
At Stage E 1 six units are tested. If each unit individually presents a result equal to or greater than Q
+ 5%, the product complies with what was specified, and Stage E2is not necessary.
Stage E2
If the criterion for Stage E 1 is not met, repeat the test with another six units. If the average of the
twelve units tested (Stages E 1 and E2) is greater than or equal to Q, and if none of the units tested
presents a result lower than Q – 15%, the product complies with what was specified, and it is not
necessary to perform Stage E 3 .
Stage E3
If the criterion for Stage E 2 is still not met, repeat the test with another 12 units. If the average of the
24 units tested (Stages E 1, E2 and E3) is greater than or equal to Q, at most two units present results
lower than Q – 15% and no unit presents results lower than Q – 25%, the product complies with
specification. If the criterion for Stage E 3 is not yet met, the product is considered unsatisfactory.
The product complies with the test if the results meet the requirements described in Table 2, unless
otherwise specified in the individual monograph. The terms Q1 and Q2 correspond to the minimum
and maximum quantity of drug dissolved in each time range specified in the monograph, expressed
as a percentage of the declared quantity. At the last time the specification can only be presented with
a minimum Q value. The terms L 1, L2 and L3 refer to the three possible stages of release evaluation
(L).
Table 2 – Acceptance criteria for the dissolution test (release) carried out for extended-release dosage forms.
Number of
Stages Acceptance criteria
units tested
Each individual result fits in the established range (Q1 and Q2) for each given
L1 6
time and no individual result is inferior to the Q of the last time.
The average of 12 units (L 1 + L2 ) fits in the established range (Q1 and Q2) for
each given time and is not inferior to the Q of the last time. No individual unit
L2 6 presents a result that exceeds the limits of Q1 and Q2 by 10% of the declared
quantity, for each given time, and no individual result provides a value lower
than the Q of the last time that exceeds the declared quantity by 10%.
The average of 24 units (L 1 + L2 + L3 ) fits in the established range (Q1 and
Q2) for each given time and is not inferior to the Q of the last time. A
maximum of two units out of the 24 tested present results that exceed Q1 and
Q2 limits by 10% of the declared quantity for each given time, and a
maximum of two units out of the 24 tested present results with a value lower
L3 12
than the Q of the last time that exceeds in 10% the declared quantity in 10%.
No individual unit presents a result that exceeds the limits of Q1 and Q2 by
20% of the declared quantity, for each given time, and no individual result
provides a value lower than the Q of the last time that exceeds the declared
quantity by 20%.
The product complies with the test if the results meet the requirements shown in Table 3 in the Acid
Stage (Methods A or B) and also the requirements indicated in Table 4 in the pH 6.8 buffer Stage
(Methods A or B), unless otherwise specified in the individual monograph. Use the Q value indicated
in the product monograph and, when not specified, use 75% as the Q value in the pH 6.8 Buffer stage.
The terms A1, A2 and A3 refer to the three possible evaluation stages in the Acid Stage (A) and the
terms B1, B2 and B3 refer to the three possible evaluation stages in the Buffer stage pH 6.8 (B).
Table 3 – Acceptance criteria for the Acid stage dissolution test (Methods A or B) carried out for delayed-release
dosage forms.
Number of
Stages Acceptance criteria
units tested
A1 06 No individual unit has a dissolved quantity greater than 10% of the declared.
The average of 12 units (A1 + A2) is not more than 10% of the declared
A2 06 quantity and no individual unit has a dissolved quantity greater than 25% of
the declared quantity.
The average of 24 units (A1 + A2 + A3 ) is, at most, 10% of the declared
A3 12 quantity and no individual unit has a dissolved quantity greater than 25% of
the declared quantity.
Table 4 – Acceptance criteria for the pH 6,8 Buffer stage dissolution test (Methods A or B) carried out for
delayed-release dosage forms.
Number of
Stages Acceptance criteria
units tested
B1 06 Each unit has a result greater than or equal to Q + 5%.
Average of 12 units (B1 + B2) is equal to or greater than Q and no unit has a
B2 06
result lower than Q – 15%.
Average of 24 units (B1 + B2 + B3) is equal to or greater than Q, at most two
B3 12 units have results less than Q – 15% and no unit has results less than Q –
25%.
The uniformity of unit doses of pharmaceutical preparations can be evaluated by two methods: Weight
variation and content uniformity. The application of each method, considering the pharmaceutical
preparation, dose and proportion of the drug, is shown in Table 1.
Table 1 – Application of the Content Uniformity (CU) or Weight Variation (WV) method
according to the pharmaceutical preparation, dose and proportion of the drug.
Drug dose and proportion
Pharmaceutical
Type Subtype ≥ 25 mg and < 25 mg or
preparation
≥ 25% < 25%
Uncoated tablets WV CU
coated film WV CU
others CU CU
Hard capsules WV CU
soft suspensions, emulsions or gels CU CU
solutions WV WV
sole ingredient WV WV
Solids stored in single-
dose containers multiple lyophilized solution in final
WV WV
ingredients container
others CU CU
Solutions stored in
WV WV
single-dose containers
Others CU CU
The Content Uniformity method for unit dose preparations is based on the assay for the individual
content of the active ingredient from a number of unit doses to determine whether the individual
content is within specified limits. The Content Uniformity method can be applied in all cases.
The Weight Variation method can be applied to the following dosage forms:
2. solids (including powders, granules and sterile solids) packaged in single-dose containers that do
not contain other added substances, whether active or inactive;
3. solids (including sterile solids) packaged in single-dose containers, containing or not added active
or inactive substances, which have been prepared from homogeneous lyophilized solutions in the
final containers, and are labeled in such a manner as to indicate this mode of preparation;
4. hard capsules, uncoated or film-coated tablets, containing 25 mg or more of the active substance,
comprising 25% or more by weight of the unit dose or, in the case of hard capsules, the content of the
capsule. The uniformity of other active substances present in smaller proportions must be
demonstrated by the Content Uniformity method.
The Content Uniformity method is required for all dosage forms that do not meet the specified
conditions for applying the Weight Variation method.
CONTENT UNIFORMITY
To determine the uniformity of unit doses by the method of content uniformity, separate at least 30
units and proceed as described for the pharmaceutical preparations indicated. When the amount of
active ingredient in a unit dose is different from that specified in the assay, make adjustments to the
dilution of the solutions and/or to the volume of the aliquots to obtain the concentration of active
ingredient in the final solution similar to that in the assay. In case of titration assay, use titrant with
different concentration, if necessary, to consume an adequate volume of titrant. Consider any
modification of dilutions to perform calculations.
When there is a special procedure for the content uniformity test in the individual monograph, make
the necessary correction of the results obtained as described below.
1. Weigh amount of product units sufficient to carry out the assay and the special content uniformity
test procedure presented in the individual monograph. Pulverize tablets to fine powder (or mix
contents of capsules, solutions, suspensions, emulsions, gels or solids in single-dose containers) to
obtain a homogeneous mixture. If obtaining a homogeneous mixture is not possible, use appropriate
solvents or other procedures to obtain a solution containing the drug. Use appropriate aliquots of this
solution for the specified tests.
2. Analyze, separately, portions of the sample, accurately measured, according to the procedure
indicated for the assay (D) and the special procedure indicated for content uniformity (E), described
in the individual monograph.
3. Calculate the amount of drug by average weight using the results obtained by the assay procedure
(D) and the special procedure (E).
F = D/S
where
D = amount of active ingredient by average weight of the pharmaceutical preparation obtained by the
assay procedure;
E = amount of active ingredient by average weight of the pharmaceutical preparation obtained by the
special procedure. If (100|D – E|)/D is greater than 10, the use of F is not valid.
2. The correction will be applied when F value is between 0.900 and 0.970 and between 1.030 and
1.100 and must be carried out by calculating the amount of drug in each unit, multiplying the
quantities obtained in the special procedure by the correction factor F.
Analyze 10 units individually as indicated in the individual monograph for the assay, unless a special
procedure for content uniformity is described in the monograph. Calculate the Acceptance Value
(AV).
Analyze 10 units individually as indicated in the individual monograph for the assay, unless a special
procedure for content uniformity is described in the monograph. Carry out the test, individually, in a
homogeneous quantity of material that is removed from each container under normal conditions of
use. Express the result as quantity dispensed per unit. Calculate the Acceptance Value (AV).
̅ | + 𝑘𝑠
AV = |𝑀 − 𝑋
WEIGHT VARIATION
To determine the uniformity of unit doses by the method of weight variation, separate at least 30 units
and proceed as described for the pharmaceutical preparations indicated. The amount of drug per unit
is estimated from the result of the assay and the individual weights, assuming homogeneous
distribution of the active ingredient. Estimated individual quantities ( 𝑥𝑖 ) are calculated according to
the formula:
𝑥𝑖 = 𝑝𝑖 × A/P
where
𝑝𝑖 = individual weights of units or contents of tested units;
A = amount of active ingredient, expressed as a percentage of the declared quantity, determined in
the assay;
P = average weight of the units used in the assay.
Weigh, accurately and individually, 10 tablets. From the assay result and the individual weight of
each tablet, estimate the quantity of active component in each unit and express the individual results
as a percentage of the declared quantity. Calculate the Acceptance Value (AV).
Hard capsules
Weigh, accurately and individually, 10 capsules, preserving the identity of each one. Carefully
remove contents and weigh empty capsules. Calculate the content weight of each capsule and, from
the assay result, estimate the amount of active ingredient in each capsule. The individual result is
expressed as a percentage of the quantity stated. Calculate the Acceptance Value (AV).
Soft capsules
Weigh, accurately and individually, 10 capsules, preserving the identity of each one. Cut the capsules
with a slide and remove the contents, washing the shells with a suitable solvent. Place the shells at
room temperature for 30 minutes for the complete evaporation of the solvent, taking precautions to
avoid the addition or loss of humidity. Weigh the empty capsules and calculate the content weight of
each capsule. Estimate the amount of active ingredient in each capsule from the assay result and from
the content weight of each capsule. Calculate the Acceptance Value (AV).
Weigh, accurately and individually, the quantity of liquid that is removed from each of 10 containers
under normal use conditions. If necessary, calculate the equivalent volume of removed content after
density determination. Estimate the amount of active ingredient in each container from the assay
result and from the content weight removed from the individual containers. Calculate the Acceptance
Value (AV).
Calculate the Acceptance Value as described in Acceptance Value for Content Uniformity, except that
the individual active component quantities in the units are replaced by the estimated individual
quantities.
CRITERIA
Apply the following criteria for both Content Uniformity and Weight Variation, unless otherwise
indicated in the individual monograph.
The product meets the unit dose uniformity test if the calculated Acceptance Value for the first 10
units tested is not greater than L1. If the Acceptance Value is greater than L1, test another 20 units and
calculate the Acceptance Value. The product meets the unit dose uniformity test if the final
Acceptance Value calculated for the 30 units tested is not greater than L1 and the amount of active
ingredient of any single unit is less than (1 – L2 × 0.01)M or greater than (1 + L2 × 0.01)M. Unless
otherwise indicated in the individual monograph, L1 is 15.0 and L2 is 25.0.
Table 2 – Terms and expressions for calculating the Acceptance Value (AV).
Variable Definition Conditions Values
X Average of individual contents
(x1, x2,..., xn), expressed as a
percentage of the declared
quantity.
x1, x2,..., xn Individual contents of the tested
units, expressed as a percentage
of the declared quantity.
n Number of units tested
∑(𝑥𝑖 − 𝑋̅)2 )
[ ]
𝑖=1
_______________
𝑛−1
M to be used Reference value If 98.5% ≤ 𝑋̅ ≤ 101.5%, M = 𝑋̅ (AV = ks)
when then
T ≤ 101.5
If 𝑋̅ < 98.5%, then M = 98.5%
(case 1)
(AV= 98.5−𝑋̅ + ks)
If 𝑋̅ > 101.5%, then M = 101.5%
(AV−𝑋̅ -101.5 + ks)
M to be used Reference value If 98.5% ≤ 𝑋̅ ≤ T, then M = 𝑋̅ (AV = ks)
when
If 𝑋̅ < 98.5%, then M = 98.5%
T ≤ 101.5
(AV= 98.5−𝑋̅ + ks)
(case 1)
If 𝑋̅ > T, then M =T (AV= 𝑋̅ −T + ks)
Acceptance General formula:
Value (AV). |M − 𝑋| + ks
The calculations are
specified above for the
different cases.
L1 Maximum value allowed for L1 = 15.0 unless
acceptance value otherwise specified in the
individual monograph
L2 Maximum allowable deviation No individual result is less L2 = 25.0 unless
for each unit tested from the than otherwise specified in the
value of M used in the (1 – L2 × 0.01) M individual monograph
acceptance value calculations. or greater than
(1 + L2 × 0.01)M
T Average of the limits specified T equals 100% unless
in the individual monograph for another value has been
the stated quantity or potency, approved for stability
expressed as a percentage. reasons; in these cases, T is
greater than 100%.
The specifications required for pharmaceutical preparations are described in the specific monographs.
Contamination by particles of preparations for parenteral use and of preparations for perfusion
consists of non-soluble and mobile foreign particles, in addition to gas bubbles that are unintentionally
found in these preparations. For the determination of particulate contamination, 2 methods are
specified below: method 1 (Light Obscuration Particle Count Test) and method 2 (Optical Microscopy
Particle Count Test). For the determination of non-visible particles in injectable preparations and in
perfusion preparations, preferably use method 1. In certain preparations, however, it may be necessary
to carry out particle counting tests by light blocking and, later, by optical microscopy in order to be
able to conclude as to the conformity of the obtained results.
Screening for non-visible particles performed using one of these methods, or even both, is not possible
for all injectable preparations. When method 1 is not applicable, for example in the case of
preparations that are not very clear or highly viscous, the test is carried out using method 2 (in the
case of emulsions, colloidal solutions and liposome preparations). Likewise, a particle counting test
by optical microscopy may also be required in the case of products which form air or gas bubbles
when passing through the detector. If the viscosity of the preparation is such that examination by
either method is impossible, a quantitative dilution with an appropriate diluent may be carried out in
order to reduce the viscosity to the degree considered sufficient to permit testing.
The results obtained when examining a unit or a group of units cannot be reliably extrapolated to
other units that have not been analyzed. Consequently, it is advisable to establish statistically valid
sampling plans to draw valid conclusions from the collected data for particulate material
contamination in a large group of units.
The water used in the tests is free from particles. Particle-free water can be obtained by membrane
filtration with a 0.22 μm porosity.
Apparatus
Use particle counter with operation based on the light blocking principle that allows the determination
of the size of particles and their number according to their dimensions.
Calibration
Calibrate the apparatus with the aid of standard spherical particles with a size between 10 to 25.μm.
These standard particles are dispersed in particle-free water. Avoid aggregation of particles during
dispersion.
Precautions
Carry out the test under conditions of limited contamination, preferably in a laminar flow hood. Wash
glassware and used filtration apparatus, with the exception of filtering membranes, with a warm
detergent solution and rinse with water until all detergent is removed. Immediately before use, rinse
the apparatus from top to bottom, internally and externally with particle-free water.
Take care not to introduce air bubbles into the sample to be analyzed, especially when sample aliquots
are being transferred to the reading accessory.
To check the suitability of the ambient, the glassware and the water used, count the particles in five
samples of 5mL of particle-free water, according to the method described in this chapter. If the
number of particles larger than 10 μm exceeds 25, for the total volume of 25 mL, the ambient is not
suitable to carry out the test.
Procedure
Homogenize the sample through 25 consecutive slow, gentle inversions of the container. Remove
bubbles by allowing the sample to stand for two minutes. Transfer four portions not smaller than
5 mL, and determine the number of particles with a size equal to or greater than 10 and 25 μm.
Disregard the result obtained with the first aliquot, and calculate the average number of particles for
the sample under examination.
Assessment
Use test A, test B or test C, as well as the number of samples, as indicated in the specific monograph
of the pharmaceutical preparation.
Test A – Solutions for injectables in containers, with declared volume, greater than 100 mL. The
sample complies with the test if the average number of particles with a size equal to or greater than
10 μm present in the units tested does not exceed 25 particles per mL and the number of particles
with a size equal to or greater than 25 μm does not exceed three per mL.
Test B – Solutions for injectables in containers, with declared volume, equal to or less than 100 mL.
The sample complies with the test if the average number of particles with a size equal to or greater
than 10 μm present in the units tested does not exceed 6000 particles per container and the number of
particles with a size equal to or greater than 25 μm does not exceed 600 particles per container.
Test C – Powders for injectables in containers, with declared volume, equal to or less than 100 mL.
The sample reconstituted with water or appropriate particulate-free diluent complies with the test if
the average number of particles, with a size equal to or greater than 10 µm present in the units tested,
does not exceed 10.000 particles per container and the number of particles with the same size or
greater than 25 μm does not exceed 1000 particles per container.
Apparatus
Use an appropriate binocular microscope, a filtration device to trap particle contamination and a filter
membrane. The microscope equipped with a calibrated ocular micrometer, with an objective
micrometer, a cross-movement stage capable of maintaining and traversing the entire filtration
surface of the filtering membrane, two appropriate illuminators that allow episcopic illumination and
oblique illumination, adjusted for magnification of 100 ± 10 times.
The ocular micrometer is a circular reticle and comprises a large circle divided into quadrants, by
crisscross lines, black and transparent reference circles with a diameter of 10µm and 25µm with a
magnification of 100 and a linear graduated scale of 10 by 10µm (Figure 1).
The large circle is called the reticle field of view. Two illuminators are required, an episcopic
illuminator for bright background, internal to the microscope, and an external adjustable auxiliary
illuminator, adjustable to allow oblique illumination reflected at an angle of 10-20°. The filtering
device for retaining the particular contamination comprises a filter holder made of glass or other
suitable material, a vacuum source and a suitable filtering membrane. The filter membrane, of
appropriate dimensions, is black or dark gray in color; is covered or not with a grid and the pore size
is less than or equal to 1.0 μm.
Central crossing
Reference circle
Linear Scale
Calibration
General precautions
Carry out the test under conditions of limited contamination, preferably in a laminar flow hood. Wash
glassware and used filtration apparatus, with the exception of filtering membranes, with a warm
detergent solution and rinse with water until all detergent is removed. Immediately before use, wash
both sides of the filter membrane, thoroughly rinse the apparatus from top to bottom, internally and
externally with particulate-free water.
To check the suitability of the ambient, the glassware and the water used, count the particles in 50
mL of particle-free water, according to the method described in this chapter. If the number of particles
of 10µm or larger exceeds 20, or if more than 5 particles of 25µm or larger are present, the ambient
is not suitable for testing.
Procedure
Homogenize the sample through 25 consecutive slow, gentle inversions of the container. If necessary,
carefully remove the closing device. Wash the outer surfaces of the vial opening with a jet of
particulate-free water and remove the closure avoiding any contamination of the contents.
For large volume parenteral preparations, carry out the test in separate units. In the case of large-
volume or small-volume parenteral preparations equal to or greater than 25 mL, less than 10 packs
may be sufficient for the test according to an appropriate sampling plan. For small volume parenteral
preparations, less than 25 mL, bring together the content of 10 units or more in a clean container so
as to obtain a minimum volume of 25 mL; in justified and authorized cases, the problem solution can
be prepared by mixing the contents of an appropriate number of vials and making up 25 mL with
particulate-free water or an appropriate particulate-free solvent, when particulate-free water is not
appropriate. Small-volume parenteral preparations, whose volume is greater than or equal to 25 mL,
can be examined individually.
In the case of powders for parenteral use, reconstitute the preparation with particulate-free water or a
suitable solvent free from particle contamination, when particulate-free water is not suitable.
Moisten the inside of the filter holder fitted with the filter membrane with a few milliliters of
particulate-free water. Pour the entire sample (mixture of test contents or the unit under test) onto the
filter and apply vacuum. If necessary, add, little by little, portions of the solution until the total volume
is filtered. After the last addition, start washing the inner walls of the filter holder using a jet of
particulate-free water. Maintain the vacuum until the surface of the filter membrane is free of liquid.
Place the filter in a Petri dish and air dry, leaving the dish slightly open. When the filter is dry, place
the Petri dish on the microscope stage, scan the entire filter membrane over the light reflected from
the illuminator and count the number of particles with a size greater than or equal to 10 μm and the
number of particles of size greater than or equal to 25 μm. It is also possible to carry out partial
counting and determine by calculation the total number of particles retained in the filter. Calculate
the average number of particles present in the sample. To determine the particle size with the aid of
the circular crosshair, transform the image of each particle into a circle and then compare with the
reference circles of the 10μm and 25μm crosshairs. Thus, the particles maintain their initial position
within the reticle field of view and do not overlap the reference circles for comparison purposes. The
inside diameter of the reticle transparent reference circles is used to determine the size of the white
or transparent particles, whereas the dark particle size is determined with the outside diameter of the
black and opaque reticle reference circles. When carrying out a particle counting test under a
microscope, do not attempt to measure or enumerate amorphous, semi-liquid or morphologically
indistinct matters that resemble a stain or discolored area of the filter membrane. These materials may
have a low or no shine and have a gelatinous appearance or a filmy appearance. Assessment
interpretation can be facilitated by carrying out a particle count test by retaining light on a sample of
the solution.
Assessment
Use the criteria below, according to the volume of samples or as indicated in the specific monograph
of the pharmaceutical preparation.
In preparations arranged in containers with a nominal content greater than 100 mL, the preparation
satisfies the test if the average number of particles present in the units examined is, at most, 12 per
milliliter for particles with a size greater than or equal to 10μm and of , at most, two particles per
milliliter for those with a size greater than or equal to 25 μm.
In preparations arranged in containers with a nominal content equal to or less than 100 mL, the
preparation satisfies the test if the average number of particles present in the units examined is, at
most, 3000 per container for particles of size greater than or equal to 10μm and not more than 300
per container for particles greater than or equal to 25μm.
Apparatus
The apparatus (Figure 1) is composed of an observation post, comprising: a matte black panel, of
appropriate dimensions, placed in a vertical position, a non-glare white panel of appropriate
dimensions, placed in a vertical position next to the black panel, a ramp of adjustable lighting, with a
shielded white light source and a suitable diffuser (a lighting system containing 2 fluorescent lamps
of 13W, with a wavelength of 525 nm each, is appropriate).
The luminous intensity at the observation point is kept between 2000 lux and 3750 lux and a higher
intensity is advisable for colored glass or plastic containers.
Adjustable lighting
Non-glare
Matte white panel
black panel
Non-glare
white panel
Procedure
Remove the labels if necessary, wash and dry the outside of the container. Gently shake and invert
each container carefully, avoiding the formation of air bubbles, and observe for approximately five
seconds against the white panel. Repeat this procedure observing the container against the black
panel. Note the presence of any particles.
PROCEDURE
Dripping must be carried out with the flask inverted in the vertical position or according to the drip
angle declared by the manufacturer, allowing the flow by gravity, at a constant rate, without any type
of additional pressure. Light pressure can be applied to polyethylene flasks.
Separate 30 units Carry out the test using 10 units, in an ambient with a controlled temperature of
(20 ± 2) ºC. For each unit determine the mass relative to the number of drops corresponding to 1 mL,
as declared by the manufacturer. If this ratio is not stated, use 20 drops for the test.
Calculate the number of drops per milliliter for each unit tested (Nt) according to the formula:
(𝑁1 × 𝜌)
𝑁𝑡 =
𝑚𝑖
where
N1 = number of drops used in the test, which can be the number of drops declared per milliliter (Nd)
or 20 drops;
ρ = mass density of the product, in g/mL, determined at 20 ºC, as described in Determination of
mass density and relative density (5.2.5).
mi = mass, in g, corresponding to the number of drops used in the test.
Calculate the amount of drug, in mg/drop, for each unit tested (qt), as per the formula:
𝑄
𝑞𝑡 =
𝑁𝑡
where
Q = amount of drug in mg/mL determined in the assay;
Nt = number of drops per milliliter for each unit tested
Calculate the percentage in relation to the declared quantity, for each unit tested (%Qt or %qt), using
one of the formulas below:
𝑞 𝑞
%𝑄𝑖 = (𝑄𝑑 /𝑡𝑁 ) × 100 or %𝑞𝑡 = 𝑞 𝑡 × 100
𝑑 𝑑
where
qt = drug amount, in mg/drop, calculated for each unit tested;
∑ %𝑄𝑖
̅̅̅̅̅ =
%𝑄
𝑛
∑(%𝑄𝑖 − ̅̅̅̅̅
%𝑄 )2
𝑠=√
𝑛−1
100 × 𝑠
𝐷𝑃𝑅 =
%𝑄
where
%Qi = percentage in relation to the declared quantity calculated for each unit tested;
s = standard deviation;
n = number of units tested;
CRITERIA
The product meets the test requirements if the individual percentage, for each of the 10 units tested,
is between 85.0% and 115.0% of the declared quantity and the relative standard deviation (RSD) is
not greater than 6.0 %.
If a unit is outside the range of 85.0% to 115.0% of the stated quantity, or if the RSD is greater than
6.0%, or if both conditions are met, test another 20 units.
The product meets the test if not more than one unit is outside the range of 85.0% to 115.0% of the
declared quantity, no unit is outside the range of 75.0% to 125.0% and the RSD of the 30 units tested
is not more than 7.8%.
For activities that require exact weighing, in the determination of mass equal to or greater than 50mg,
use an analytical balance of 100mg to 200mg capacity and 0.1mg sensitivity. For quantities lower
than 50mg, use an analytical balance of 20g capacity and 0.01mg sensitivity.
APPARATUS
The analytical balances to be used in this test must be single-pan, preferably electronic.
Scales must have an adequate device that enables the verification of the applied load, provided they
are periodically calibrated by means of measured reference masses.
- protection cabinet or box, with appropriate openings to allow operations inside and exclude drafts;
- be installed on a base of compact and resistant material (marble, granite, metal or rubber, for
example);
- level indicator (gravimetric or hydraulic) and device that allows its leveling; – be installed on a
damping system (magnetic, pneumatic or hydraulic, for example) to promptly restore equilibrium;
- system that allows the reading of the mass (through dials and/or optical scale projection, etc.).
They must also support their full load without suffering undue tension that could compromise their
sensitivity in serial weighing under these conditions.
The analytical balance must be placed leveled upon a firm and heavy table or shelf, protected by
shock absorbers such as cork mats or rubber sheets, or on a concrete counter, supported by pillars that
are fixed to the floor or connected to the elements of building construction to prevent vibrations. It
must be in an isolated place, which offers safety and stability to the measuring, in an environment
with a relatively dry atmosphere, protected from the attack of acid gases and vapors, away from heat
sources (direct sunlight, ovens, heaters, muffle furnaces, etc.) and of drafts.
The pan and other parts of the scale, including its enclosure, must remain clean, free of dust and
substances that accidentally fall onto the scale pan or the case floor. Such materials must be removed
immediately.
The bodies to be weighed must not be placed directly on the pan. For this purpose, papers or
containers suitable for the mass are used, such as beakers, watch glasses, crucibles, porcelain capsules
and weighing bottle with or without a lid.
The moving parts of the scale and weights must not be touched by hand. For this purpose, appropriate
tweezers are used, which must be kept in the weight box.
Desiccant agents such as silica gel or calcium chloride can be placed inside the enclosure to maintain
a relatively dry atmosphere.
When the scale is not in use, its doors must remain closed and locked.
The sensitivity of analytical balances must be periodically inspected and checked by a qualified
expert.
The material to be weighed must be in thermal equilibrium with the air inside the scale protective
enclosure in order to avoid errors due to convection currents, as well as humidity condensation on
cold bodies.
The scale must be leveled at the time of use. The balanced position with or without load should be
checked several times at 10% of full load and with full load. The equilibrium difference found in two
serial determinations made with equal weights must not exceed 0.1 mg for analytical balances
(maximum 200 g) and 0.01 mg for analytical balances (maximum 20 g).
Both the weights and the material to be weighed must be placed in the center of the pan. During
weighing operations, the enclosure doors must be closed.
The melting range of a substance is defined as the range between the temperature at which the
substance starts to liquefy or form drops on the walls of the capillary tube and the temperature at
which the substance is completely melted.
A melting transition can be instantaneous for a highly pure material, but a gap is generally observed
from the beginning to the end of the process. There are different factors that influence this transition
and they should be standardized when describing the procedure. These factors include: sample
quantity, particle size, heat diffusion performance, and speed of heating, among others.
For pharmacopoeial purposes, the melting point or melting range is reported as the temperature at
which the first liquid phase is observed and the temperature at which there is no more apparent solid
phase, except for those substances that melt with decomposition or specified otherwise in the
individual monograph.
METHOD I
Apparatus I
It consists of a glass container (C) for a transparent liquid bath, a mixing device (D), a thermometer
(A) and a suitable heat source (see Figure 1). According to the required working temperature, the
bath liquid can be one of the following or whatever is appropriate:
Immersion
Level
The bath liquid must be deep enough to allow the thermometer to immerse at the specified depth so
that the bulb is approximately 2 cm from the bottom of the bath. Heat can be supplied by a flame or
electrically. The capillary tube is approximately 10cm long and between 0.8mm and 1.2mm in
internal diameter, with walls from 0.1mm to 0.3mm thick, and must be closed at one of its ends,
unless otherwise specified in the individual monograph. A stirrer device that guarantees the
homogeneity of the bath temperature must be used.
Procedure
Reduce the sample to a fine powder and dry it in a vacuum desiccator over a suitable desiccant for 24
hours.
Load the dry capillary tube with a sufficient quantity of powder to form a column of 3 mm to 4 mm
in height, after having compressed with moderate strokes on a solid surface. Connect the capillary
tube to the thermometer, both moistened with the bath liquid. Adjust height so that the sample
contained in the capillary is close to the thermometer bulb (B).
Adapt an auxiliary thermometer (E) so that the center of the bulb is as close as possible to the stem
of the main thermometer (A) at a point equidistant from the surface of the bath and from the division
corresponding to the expected melting point.
Heat the bath to a temperature of 10°C below the expected melting point. Insert the thermometer with
the capillary attached and continue heating in such a manner that the temperature rises at a rate of
1°C to 2°C per minute, depending on the stability of the substance.
Record the reading of the auxiliary thermometer at the end of the sample melting and, if necessary,
apply the correction for the emerging column using the following formula:
𝑡𝑐 = 𝑘 × 𝑁(𝑇 − 𝑡)
where
tc = correction that must be added to the observed melting temperature;
k = correction constant by the coefficient of liquid expansion of the thermometer. In the case of
mercury, the value is 0.00016;
N = number of degrees of the main thermometer column between bath level and the observed melting
temperature;
T = melting temperature;
t = temperature registered by the auxiliary thermometer.
Carry out the determination at least in triplicate. To do this, allow the bath to cool to 10°C below the
melting point or to a lower temperature and repeat the procedure using new portions of the sample.
Apparatus II
It consists of a metal block that can be heated at a controlled speed, whose temperature can be
monitored by a sensor or thermometer. The block allows the capillary tube containing the test
substance to be inserted in it and to monitor the melting process through visual control or
automatically.
Procedure
Reduce the sample to a fine powder and dry it in a vacuum desiccator over a suitable desiccant for 24
hours.
Load the dry capillary tube with a sufficient quantity of powder to form a column of 3 mm to 4 mm
in height, after having compressed with moderate strokes on a solid surface.
Heat the bath to a temperature of 10°C below the expected melting point. Insert the capillary into the
block and record the temperature at the beginning and end of melting. Continue heating in such a
manner that the temperature rises at a rate of 1°C to 2°C per minute.
Carry out the determination at least in triplicate. To do this, allow the bath to cool to 10°C below the
melting point or to a lower temperature and repeat the procedure using new portions of the sample.
METHOD II
Procedure
Carefully melt the sample at the lowest possible temperature and introduce the melted material into
an capillary open at both ends to form a column about 10mm high. Cool the charged capillary to a
temperature equal to or less than 10°C for approximately 24 hours. Join the capillary to the
thermometer and adjust height so that the sample contained in the capillary is close to the
thermometer bulb. Place in water bath and heat as indicated in Method I, Apparatus I, except that
when it reaches a temperature of approximately 5°C below the expected melting point, the
temperature is increased at a rate of 0.5°C per minute. The temperature at which the sample begins to
rise inside the capillary tube is recorded as the melting point. Carry out the determination at least in
triplicate using different portions of the sample.
METHOD III
For petroleum jelly, fatty substances or others with a creamy consistency (semi-solid).
Procedure
Melt the sample under agitation until it reaches a temperature between 90C°C and 92°C and allow
the melted substance to cool to a temperature between 8 °C and 10C°C above the expected melting
point. Cool the thermometer bulb to 5°C, dry and, while it is still cold, submerge it in the melted
sample approximately to the middle of the bulb. Remove immediately and keep in an upright position
until the surface of the sample deposited on the bulb solidifies. Place in water bath at a temperature
not exceeding 16°C for approximately five minutes.
Adapt the thermometer inside a test tube by means of a perforated stopper, so that its lower end is
about 15 mm above the bottom of the tube. Suspend the test tube in water bath at a temperature of
16°C and raise the temperature of the bath to 30°C, at a rate of 2°C per minute, and then at a rate of
1°C per minute until the first drop detaches from the thermometer. The temperature at which this
occurs is the melting point. For each determination use a fresh-fused portion of the sample. Carry out
the determination in triplicate. If the maximum difference between the determinations is less than
1°C, determine the average of the obtained values. Otherwise, carry out two other determinations and
calculate the average of the five.
Distillation range is the temperature range corrected for the pressure of 101.3 kPa (760 mm of Hg),
within which the liquid, or specific fraction of the liquid, fully distills.
APPARATUS
Use apparatus as suggested in Figure 1 where A is a distillation flask with a capacity of 100 mL
connected to condenser B. Adapter C is attached to the lower end of B. A 50 mL cylinder graduated
in 0.2 mL is used as a collector. The thermometer must be fitted to the flask so that the temperature
sensor is located in the center of the neck and about 5mm below the level of the side tube. Heating
(via gas, electric or bath) should be selected according to the nature of the substance.
Figure 1 – Apparatus for determining the distillation range (dimensions in mm). A, distillation flask; B,
condenser; C, adapter.
PROCEDURE
Add approximately 50 mL of the sample to the flask so that it does not leak into the side tube. Add
glass beads or other suitable porous material. Adapt the thermometer to the flask and heat, slowly,
protecting the system from drafts.
Record the temperature at which the first five drops of distillate are collected. Adjust heating to obtain
distillate at a flow rate of 3 mL to 4 mL per minute. Record the temperature at which the last drop
evaporates from the distillation flask or when the specified fraction is collected. Keep the distillate at
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.3-00
the same temperature at which the liquid was originally measured and record the volume of the
distillate.
Compare the values obtained for the boiling point, distillation range and distillate volume with the
respective specifications of the monographs.
t1 = t2 + k (101.3 – b)
where
t1 = temperature corrected;
t2 = temperature observed at atmospheric pressure b;
k = conversion factor (Table 1), unless this factor is not considered;
b= atmospheric pressure, expressed in kilopascals, during distillation.
Note 1: When the liquid is pure, most of it boils at a constant temperature (in a range of 0.5°C). This
temperature is the boiling point of the liquid.
Note 2: liquids that distill below 80°C must be cooled between 10°C and 15°C before measuring the
volume and the cylinder that receives the distillate must be immersed in an ice bath.
Note 3: when the boiling point is above 150 ºC, you can replace the water condenser with air
condenser.
For pure substances that melt without decomposition, the liquid congealing point is equal to its
melting point.
APPARATUS
The device (Figure 1) consists of a test tube of approximately 25mm in internal diameter and 150mm
in length suspended through a suitable stopper inside a second larger tube, 40mm in internal diameter
and 160mm in length, forming an air jacket that prevents sudden changes in temperature. This system
is fixed by a claw in the center of the beaker with a capacity of 1000 mL containing water or a coolant
solution.
The inner tube is sealed with a stopper in order to contain a stirring rod and a thermometer with 0.2°C
divisions. The thermometer temperature sensor should be fixed approximately 15mm from the bottom
of the tube. The stirrer is a glass rod fitted with a ring at its lower end (Figure 1).
PROCEDURE
Transfer the sample in sufficient quantity to reach 30 mm in the inner tube. Transfer the coolant
mixture set at 5°C below the expected congealing point to the beaker. When the sample is cooled to
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.4-00
approximately 5°C above congealing point, move the stirrer vertically between the surface and the
bottom for approximately 20 cycles per minute and record the thermometer temperature every 30
seconds. Stop shaking when the temperature remains constant or shows a slight increase. Record the
temperature every 30 seconds for at least three minutes after the temperature starts to drop again.
Record the maximum on the temperature-time curve, which occurs after the temperature remains
constant, or shows a slight increase, and before the temperature starts to decrease again. Congealing
point is assigned to an average of not less than three consecutive maximum points that fall within a
range of 0.4°C.
Note 1: If the substance is solid at room temperature, melt the substance and heat to a maximum of
20ºC above the expected congealing temperature before transferring to the inner tube.
Note 2: if the substance is liquid at room temperature, use bath at 15°C below the expected
congealing temperature.
When the temperature is, for example, 20°C, the formula is expressed by:
20
𝜌20 = 0,99820 × 𝑑20 + 0,0012
The relative density of a substance is the ratio of its mass by the mass of an equal volume of water,
20
both at 20°C (𝑑20 ) or by the mass of an equal volume of water at 4°C (𝑑420 ):
20
𝑑420 = 0,998234 × 𝑑20
PROCEDURE
The relative density of the substance can be determined using a pycnometer, hydrostatic balance or
densimeter. The use of these last two is conditioned to the type of apparatus available.
PICNOMETER METHOD
Use a clean and dry pycnometer, with a capacity of not less than 5 mL that has been previously
calibrated. Calibration consists of determining the mass of the empty pycnometer and the mass of its
contents with fresh-distilled and boiled water at 20°C.
Transfer the sample to the pycnometer. Adjust temperature to 20°C, remove substance excess, if
necessary, and weigh. Obtain the sample weight from the mass difference of the full and empty
20
pycnometer. Calculate the relative density (𝑑20 ) determining the ratio between the mass of the liquid
sample and the mass of the water, both at 20°C. Use relative density to calculate mass density (ρ).
𝑠𝑒𝑛 𝑖
𝑛=
𝑠𝑒𝑛 𝑟
For practical purposes, refraction is measured with reference to air and substance rather than with
reference to vacuum and substance, as the differences between the values obtained with both
measurements are not significant for pharmacopoeial purposes.
In isotropic substances, the refractive index is a constant feature at a given wavelength, temperature
and pressure. For this reason, this index is useful not only to identify the substance, but also to detect
the presence of impurities. It is used to characterize mainly fats, fatty oils, waxes, sugars and organic
solvents, as well as to identify certain drugs. It is also used to determine the purity of volatile oils.
Generally, the refractive index is determined from the sodium light at a wavelength of 589.3 nm (lane
D) and at (20 ±0.5) ºC. Hence, the value of the refractive index is expressed as 𝑛𝐷20 .
REFRACTOMETERS
Refractometers commonly used in pharmacopoeial analysis use white light, but are calibrated to
provide the refractive index in terms of wavelength corresponding to that of sodium D-lane light.
The Abbé refractometer measures the range of refractive index values of pharmaceutical substances.
Other refractometers of greater or equal precision can be used.
As the refractive index varies significantly with temperature, during the reading the sample must be
adjusted and kept at 20°C.
The device is calibrated with a standard provided by the manufacturer. To control the temperature
and clean the apparatus, the refractive index of distilled water must be determined, with values of
1.3330 at 20 ºC and of 1.3325 at 25 ºC.
The dynamic unit of viscosity, in the CGS System, is the poise. The CGS System of Units is a system
of physical measurement units, or dimensional system, of LMT typology (length, mass, time), whose
base units are the centimeter for length, gram for mass, and second for time.
The analogous dynamic unit in the International System of Units (SI) is the pascal second. Poise is
often used with the prefix centi; a centipoise (cP) is a millipascal second (mPa·s) in SI units.
CGS Sistema system – poise (P)
1 P = 1 g ∙ 𝑐𝑚−1 ∙ 𝑠 −1
By definition, poise is the force, in dynes, necessary for the displacement of a flat liquid layer, with
an area of 1 cm2, on another identical layer, parallel and distanced from the first by 1 cm, at a speed
of 1 cm/s. Poise is, however, too large for most applications, hence the centipoise, cP, corresponding
to one hundredth of poise. Sometimes it is convenient to use kinematic viscosity, which is the ratio
between dynamic viscosity and density. In this case, in the CGS system, the unit is the stokes. As an
example of what happens with absolute viscosity (measured in poise), it is more convenient to express
kinematic viscosity in centistokes (100 centistokes = 1 stoke) to characterize most liquids usual in
Pharmacy and Chemistry.
1 𝑃𝑎 ∙ 𝑠 = 1 𝑘𝑔 ∙ 𝑚−1 ∙ 𝑠 −1 = 10 𝑃
Pascal second is equivalent to 10 poise, but usually millipascal second (mPa·s) is more commonly
used. Table 1 shows the viscosity of some liquids.
The determination of viscosity – a test for which the specification of temperature is essential due to
its decisive influence on the result (in general, viscosity is inversely proportional to temperature) – is
performed based on different properties. The most frequent method is based on the flow time of
liquids through capillaries (Ostwald, Ubbelohde, Baumé and Engler viscometers) due to the devices
simplicity and affordable price. Viscometers whose working principle is the determination of the free
fall time of spheres through tubes containing the liquid under test (Höppler) or the rotation speed of
metallic axes immersed in the liquid (Brookfield, among others) are also used.
Although it is possible to determine the absolute viscosity, based on the exact dimensions of the
viscometer used, it is more frequent to calibrate the device with a liquid of known viscosity, allowing,
by comparison, the relative evaluation of the viscosity of the liquid under test. Thus, using Ostwald
viscometer or similar, the flow times t are determined1and t2of equal volumes of sample and reference
liquids, of density d1 and d2, respectively. If 𝜂2 is the viscosity of the reference liquid, the absolute
viscosity (cP) of the sample liquid can be calculated by the formula:
𝑛1 𝑡1 𝑑1
=
𝑛2 𝑡2 𝑑2
or yet
𝑡1 𝑑1
𝑛1 = 𝑛2
𝑡2 𝑑2
The quotient η 2/t2.d2 has a constant value, k, for each reference liquid, in the same viscometer. Thus,
once this value is known (usually found in the equipment manual), the formula is simplified:
𝑛 = 𝑘. 𝑡. 𝑑
The value of k can also be determined experimentally by measuring the flow time of a standard pure
liquid and applying the formula:
𝑛
𝑘=
𝑡. 𝑑
Using water as the standard, usual for the determination of low viscosity liquids, the viscosity values
recorded in Table 2 are adopted, according to the test temperature:
24 0.915
25 0.895
For highly viscous liquids (glycerin and oils in general), the relative viscosity can be determined by
the method of velocity of falling balls through the liquid, using the Höppler viscometer. This method
is also suitable for determining the absolute viscosity of liquids by applying the formula:
𝜂 = 𝑡(𝑑𝑆 − 𝑑𝐿)𝐾
where
t = ball falling time (sec).
K = ball-specific cte (mPcm3), supplied by the manufacturer. dS = ball density (g/cm3).
dL = density of the liquid (g/cm3).
The density of the liquid (dL), for a certain temperature, can be obtained from reference books (such
as handbooks), or determined experimentally.
The relative viscosity in the Höppler method can be determined by applying the formula:
𝑛1 (𝑑𝑠 − 𝑑1 )𝑡1
=
𝑛2 (𝑑𝑠 − 𝑑2 )𝑡2
where η, d and t are, respectively, the coefficient of dynamic viscosity, the density and the flow time
of equal volume of liquids 1 and 2.
OSTWALD VISCOMETER
The Ostwald viscometer is the simplest and most popular device available. It consists of a U-bent
tube (Figure 1), with one of the branches fitted with an ampoule ending in a capillary. There are two
reference lines, one immediately above the ampoule and the other above the capillary. The other
branch is wide enough to be filled with the liquid under test to a height of about 5mm below the lower
reference line. To enable the determination of viscosities over a wider range, collections of
viscometers with different calibration levels are used. The device indicated for a certain evaluation is
the one that allows the sample to flow in a period of maximum 60 seconds.
For the actual determination, transfer to the chosen viscometer, washed and dry, a sufficient quantity
of liquid to reach a level of 5mm below the lower reference line. Set the device in a thermostat (20 ºC).
After waiting for the liquid inside the device to reach the controlled temperature, aspirate the liquid
through the capillary tube/ampoule (by means of a rubber tube attached to the end) until the liquid
level slightly exceeds the upper reference line. Then release the tube and, at the instant the meniscus
reaches the upper reference line, start the precision timer, relocking it when the meniscus passes
through the lower reference line. Record the time elapsed and repeat the test several times at ranges
of a few minutes until serial times do not differ by more than 0.5 seconds. Determine the density of
the liquid under test (5.2.5), correcting the value for the density relative to water, at 20°C, and
calculate the viscosity of the liquid sample by the formula indicated, using the constant k provided or
determined by a similar procedure.
HÖPPLER VISCOMETER
The Höppler measurement system measures the time a solid ball takes to travel a distance between
two reference points within an inclined sample-filled tube. The results obtained are considered as
dynamic viscosity in the measure standardized in the International System (mPa.s). It accurately
determines the viscosity of Newtonian liquids and gases (with a special ball for gases). Among its
applications we cite research, process control and quality control, mainly used for substances with
low viscosity, between 0.6 and 100,000 mPa.s.
The Höppler Viscometer is composed of a glass tube with two marks (A and B) spaced from each
other on the column by 10mm which define the measurement distance. A ball (in glass, nickel alloy
and iron or steel) with a diameter compatible with the gauge of the glass tube is installed on top of its
liquid content. The tube is surrounded by a glass cylinder filled with circulating water under
controlled temperature. The entire set is arranged in a slightly inclined position (10% vertically), and
can be rotated 180o around an axis perpendicular to both tubes, to allow the repetition of the
determinations and the return of the ball to the initial position. The method consists of timing the
falling time (fall) that a sphere (with variable density and diameter with the respective structural
constitution) takes to traverse the space between those two marks (A and B) existing at the ends of
the glass tube. The higher the viscosity, the longer the ball will take to travel through that space. The
type of sphere to be used is chosen depending on the presumptive value of the viscosity of the liquid
under observation. In the case of blood, glass beads are used. The viscosity results of Newtonian
liquids are expressed in international standard absolute units (mPa.s)
For the actual determination, rinse the chosen viscometer, washed and dry, with the liquid used to
determine the viscosity. Adjust the apparatus probe. Choose the appropriate ball for each liquid (water
= glass ball). Completely fill the inner tube of the viscometer with liquid. Record the time for the ball
to fall between marks A and B on the viscometer. Carry out two more determinations to get the best
average.
BROOKFIELD VISCOMETER
Select the proper orifice. The guideline for orifice selection is to obtain a flow time of the liquid under
test of around 60 seconds. There must be a flow time between 20 and 100 seconds for the sample at
25°C.
The sample must be perfectly mixed. At the time of testing, the viscometer and the material to be
tested must be at (25 ± 0.1) ºC. Close the orifice with a flat glass slide and fill the sample cup to the
highest level. Pour the sample slowly, avoiding the formation of bubbles. Level the sample in the cup
using a flat glass plate. Remove the slide from the orifice. The sample will be retained in the cup.
Remove the flat glass plate and activate the timer when the sample starts to flow through the orifice.
When the first interruption in the flowing occurs, stop the timer and record the time elapsed in
seconds. Carry out the test at least in triplicate. The viscosity will be the mean of the values obtained,
expressed in mm2/s or Centistokes, with a maximum standard deviation of 3% being allowed. The
conversion from seconds to mm2/s or Centistokes is given in accordance with the manual of the
apparatus used.
Chiral substances whose molecules are not superimposable but are mirror images are called
enantiomers. They have the same physicochemical properties (density, refractive index, dipole-dipole
moment, boiling and melting points), except that they rotate the plane-polarized light at the same
quantity of degrees in opposite directions, and their reactions with other chiral substances have
different characteristics.
Optical rotation varies with temperature, the wavelength of incident light, the solvent used, the nature
of the substance and its concentration. If a solution contains two optically active substances and they
do not react with each other, the deviation angle will be the algebraic sum of the deviation angles of
both.
POLARIMETER
Polarimeters are devices that detect optical rotation visually (by equaling the intensity of light over
two fields) or through a photoelectric system, the latter being more accurate and precise than those
for visual measurement.
The measurement of optical rotation must be performed using a polarimeter capable of measuring
differences of not less than 0.05°, unless otherwise specified in the individual monograph. As a light
source, sodium, mercury vapor, xenon or halogen-tungsten lamps are used, among others, equipped
with a device that allows transmitting a monochromatic light beam. These last two lamps mentioned
are usually less expensive, in addition to having greater durability and having a wider range of
emission wavelengths compared to traditional light sources. The scale must be controlled using a
polarization reference standard, which consists of certified quartz plates. Scale linearity should be
checked periodically using a solution of standard dextrose and sucrose reference materials.
The use of lower wavelengths, such as the mercury lamp lines at 578nm, 546 nm, 436 nm, 405 nm
and 365 nm in a photoelectric polarimeter, can provide advantages in terms of sensitivity, with a
consequent reduction test substance concentration. In general, the optical rotation observed at 436 nm
is approximately double and that observed at 365 nm is approximately three times greater than that
observed at 589 nm.
The reduction in the concentration of the test substance required for measurement can sometimes be
achieved by converting it to another substance that has a significantly higher optical rotation. Optical
rotation is also affected by the solvent used in the measurement and this must be specified in all cases.
PROCEDURE
The specific optical rotation is a reference value and is calculated from the observed optical rotation
for a sample solution or liquid as specified in the monograph. Optical rotation measurements are
performed at 589.3nm at 25°C, unless otherwise specified in the individual monograph. The
experimental temperature must be maintained at ± 0.5 °C from the specified value.
When using a polarimeter with visual detection, the mean of at least five determinations must be used,
corrected by the reading of the solvent blank, for solutions, and the air, for liquids. When using a
photoelectric polarimeter, carry out a single measurement corrected by the solvent blank, for
solutions, and by the air, for liquids. Use the same polarimeter tube in the same orientation for the
sample and for the blank.
Optical rotation of solutions must be determined within 30 minutes of preparation. In the case of
substances that can undergo racemization or mutarotation, special care must be taken in standardizing
the time between which the solution is prepared and the polarimetric reading is carried out.
Unless otherwise indicated in the corresponding monograph, the specific rotation is calculated on dry
substance when the monograph determines Loss on Desiccation, on anhydrous substance when
specifying Determination of water, or free of solvents when specifying Content of residual solvents.
The accuracy and precision of optical rotation measurements can be enhanced if the following
precautions are taken:
1) The formation of air bubbles must be avoided when filling the polarimeter tube, which is
particularly necessary for micro and semi-micro tubes.
3) The optical elements must be perfectly aligned, as well as the light source in relation to the optical
path.
CALCULATIONS
The specific optical rotation is calculated from the optical rotation observed in the sample solution,
obtained as specified in the corresponding monograph.
where
α= corrected observed rotation, in degrees, at 25°C;
I= length of the polarimeter tube in decimeters;
d25 = relative density of the liquid at 25°C;
c= concentration of substance in percent weight/volume;
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.8-00
[α]25D= specific optical rotation determined at 25°C and 589.3nm (line D of the sodium light).
(𝑃𝑢 − 𝑃𝑠)
× 100
𝑃𝑚
where
Pm = sample weight (g);
Pu = weight of the weighing bottle containing the sample before drying (g);
Ps = weight of the weighing bottle containing the sample after drying (g).
PROCEDURE
Gravimetric Analysis
If necessary, reduce the substance to a fine powder by grinding quickly. Weigh an approximate
amount between 1 g to 2 g of the substance, in a weighing bottle previously desiccated for 30 minutes,
under the same conditions as used in the sample test, and cooled to room temperature in a desiccator.
Distribute the sample as evenly as possible, gently shaking the weighing bottle so that a layer
approximately 5mm thick is formed and a maximum of 10mm in the case of bulky materials. Place
the uncapped weighing bottle containing the sample together with the cap in the drying chamber. Dry
the sample under the conditions specified in the monograph (Note: the temperature specified in the
monograph must be considered to be within the range of +2 °C). Open the drying chamber, cap the
weighing bottle quickly, remove and allow to reach room temperature in a desiccator before weighing.
When the individual monograph specifies desiccation up to constant weight, drying must continue
until two consecutive weighing determinations do not differ by more than 0.50 mg per gram of
substance weighed, carrying out the second weighing after an additional hour of drying.
If the substance melts at a temperature lower than that specified for the determination of loss on
drying, keep the weighing bottle with its contents for one to two hours at a temperature of 5°C to
10°C lower than the melting temperature and then dry at specified temperature.
For the analysis of capsules, use a portion of the mixed content of at least four units. In the case of
tablets, use the powder of at least four units.
be maintained at a pressure of maximum 5mm of mercury. Heating period elapsed, allow dry air
to enter the chamber, remove the flask and, with cap still in place, allow to cool to room
temperature in a desiccator before weighing;
• drying in a desiccator, precautions must be taken to ensure that the desiccant remains active.
Calcium chloride, silica gel and phosphorus pentoxide are among the most frequent desiccant
agents.
Thermogravimetry
In the event that the individual monograph specifies that the loss on desiccation must be carried out
by thermogravimetric analysis, proceed as described in Thermal analysis (5.2.27).
In the event that the individual monograph specifies that the loss by desiccation must be carried out
on an infrared scale or with a halogen lamp, proceed as follows:
• Remove moisture from the apparatus;
• Weigh quantity of the substance to be analyzed, distribute the material evenly in the sample
collector and place inside the apparatus;
• Set the drying time and temperature as set in the individual monograph. Record the moisture value
obtained.
𝑃𝑢 − 𝑃𝑠
× 100
𝑃𝑚
where
Pm= sample weight (g);
Pu= weight of the crucible containing the sample before ignition (g);
Ps= weight of the crucible containing the sample after ignition (g).
PROCEDURE
If necessary, reduce the substance to a fine powder by grinding quickly. Accurately weigh between
1 g and 2 g of the substance without further treatment into a crucible unless preliminary drying at a
lower temperature or other special treatment is specified in the individual monograph. The crucible
(for example: platinum, porcelain, silica, quartz) must be previously calcined at 500°C, cooled in a
desiccator and tared. Distribute the sample as evenly as possible, gently shaking the crucible so that
a layer approximately 5mm thick is formed and a maximum of 10mm in the case of bulky materials.
Place the crucible in a muffle furnace, calibrated to control the temperature, and conduct the ignition
at 500ºC ± 25ºC for a period of time between two and three hours. Open the apparatus, remove the
crucible and allow to reach room temperature in a desiccator before weighing.
When the individual monograph specifies ignition up to constant weight, ignition must continue until
two consecutive weighing determinations do not differ by more than 0.50 mg per gram of substance
weighed, carrying out the second weighing after an additional hour of ignition.
Check the accuracy of the measurement and the circuit systems of the muffle furnace by controlling
the temperature at different points in the muffle furnace. The temperature variation tolerated is ±
25 °C for each point evaluated.
PROCEDURE
Accurately weigh between 1 g and 2 g of the sample or the amount specified in the monograph, in an
appropriate crucible (quartz, silica, platinum or porcelain, unless another material is specified in the
individual monograph), previously submitted to incineration at temperature specified for the sample
for 30 minutes, cooled in a desiccator and weighed. Moisten the sample with approximately 1 mL of
sulfuric acid, heat gently to as low a temperature as possible until the sample is carbonized. Cool and
moisten the residue with 1 mL of sulfuric acid, unless otherwise specified in the individual
monograph. Heat gently until no white fumes are released and carbonize immediately. Incinerate at
(600 ± 50) °C for between two and three hours, unless another temperature and/or time is specified
in the individual monograph. Cool in a desiccator, weigh and calculate the residue percentage. Unless
otherwise specified in the individual monograph, if the residue obtained exceeds the specified limit,
add 1 mL of sulfuric acid, heat and incinerate for an additional 30 minutes. Repeat this procedure
until the difference between two consecutive weighing is, at most, 0.5 mg or until the residue meets
the limit established in the individual monograph.
Calculate the percentage of the residue in relation to the substance under analysis using the following
formula:
𝑃2 −𝑃1
% residue by incineration (sulfated ash) = × 100
𝑃3
Carry out this procedure in a fume hood that is well ventilated, but protected from drafts. A muffle
furnace may be employed, if desired, and is recommended for final ignition at (600 ±50) °C.
Check the accuracy of the measurement and the circuit systems of the muffle furnace by controlling
the temperature at different points in the muffle furnace. The temperature variation tolerated is ±
25 °C for each point evaluated.
Coarse powder – one whose particles entirely pass through the sieve with a nominal mesh opening
of 1.70 mm and, not more than 40% through the sieve with a nominal mesh opening of 355 µm.
Moderately coarse powder - one whose particles entirely pass through the sieve with a nominal mesh
opening of 710 mm and, not more than 40% through the sieve with a nominal mesh opening of 250
µm.
Semi-fine powder - the one whose particles pass entirely through the sieve with a nominal mesh
opening of 355 µm and not more than 40% by the sieve with a nominal mesh opening of 180 µm.
Fine powder - one whose particles pass in their entirety through the sieve with a nominal mesh
opening of 180 µm.
Very Fine powder - one whose particles entirely pass through the sieve with a nominal mesh opening
of 125 µm.
The determination of the granulometry of powders is made by the process described below, with the
aid of sieves, whose features are standardized in the attached table.
PROCEDURE
Granulometry is determined with the aid of sieves operated by a mechanical device. This type of
device reproduces the horizontal and vertical movements of manual operation through uniform
mechanical action. To use this device, proceed as follows:
Separate at least four sieves that are described in Table 1, according to the characteristics of the
sample. Assemble the kit with the larger opening sieve over the smaller opening. Place the set on the
sieve receiver.
Weigh approximately 25 g of the sample (depending on the nature of the material, density of the
powder or granule and the diameter of the sieves to be used). Transfer the sample to the upper sieve,
distributing the powder evenly. Cap the set.
Activate the device for about 15 minutes with adequate vibration. After the end of this time, using a
suitable brush, remove all the sample retained on the upper surface of each mesh onto waterproof
paper, and weigh the powder. Also weigh the powder retained in the collector.
Calculate the percentage retained in each sieve, using the following calculation:
𝑃1
% 𝑅𝑒𝑡𝑖𝑑𝑎 𝑝𝑒𝑙𝑜 𝑡𝑎𝑚𝑖𝑠 = ∙ 100
𝑃2
where
The comparative process, unless otherwise specified, must be carried out in test tubes made of clear
glass and flat bottom, with a diameter of 15mm to 25mm, of the type used in impurity limit testing.
Tubes must be uniform.
For the evaluation, use volumes of 5 mL for both sample preparation and standard preparation,
ensuring an approximate height of 2.5 cm for liquids in the tubes. View the tubes longitudinally
against a white background, under diffused light. It is important to compare solutions under the same
conditions, including temperature (25 °C).
The sample preparation is obtained so as to be similar in color to the specified reference preparation.
A solution is colorless when it has the appearance of water or of its constituent solvent or is less
colored than the standard T color solution.
BASIC STANDARDS
Color reference solutions (SC) are obtained from three basic solutions to be prepared and stored in
hermetic flasks. From them, prepare the specified solution or solutions for comparison, as
recommended in Table 1, which contains volume indications for the preparation of 20 standard color
solutions (CS), designated with the letters of the alphabet, from A to T. Transfer the indicated volumes
(place the water last) and homogenize directly in the comparison tubes.
enough of a mixture of hydrochloric acid and water to obtain a solution containing exactly 62.4 mg
of CuSO4.5H2O per mL of solution and homogenize.
Prepare a solution containing 25 mL of hydrochloric acid and 975 mL of water. Dissolve about 55 g
of ferric chloride(FeCl3.6H2O) in approximately 900 mL of this solution, adjust volume to 1000 mL
with the same solution and homogenize. Protect solution from light and filter if precipitation occurs.
Transfer, using a pipette, 10 mL of this solution to a 250 mL iodine flask, add 15 mL of water, 3 g of
potassium iodide and 5 mL of hydrochloric acid. Allow to stand for 15 minutes. Adjust the solution
volume to 100 mL with water and titrate the released iodine with 0.1 M sodium thiosulfate VS, adding
3 mL of starch TS as indicator. Correct the volume of titrant consumed by blank determination. Each
mL of 0.1 M sodium thiosulfate VS is equivalent to 27.03 mg of FeCl3.6H2O. Adjust the solution
volume by adding enough hydrochloric acid solution and water to obtain a solution containing exactly
45.0 mg of FeCI3.6H2O per mL of solution and homogenize.
For the determination of the analyte concentration by atomic absorption, the radiation from a source
of specific wavelength according to the analyzed element falls on the atomic vapor containing free
atoms of this element in the ground state. Radiation attenuation is proportional to the analyte
concentration according to the Lambert-Beer law.
PROCEDURE
Direct Calibration Method (Method I): Prepare at least four reference solutions of the element to be
determined using the concentration range recommended by the equipment manufacturer for the
analyte. All reagents used in sample preparation must be equally included, at the same concentrations,
in the preparation of reference solutions. After calibrating the apparatus with solvent, introduce each
of the reference solutions into the atomizer three times and, after reading, record the result. Wash the
sample introduction system with water after each operation. Plot the analytical curve for the mean of
the absorbances of the three readings for each reference solution with its concentration. Prepare the
sample as indicated in the monograph, adjusting its concentration so that it falls within the
concentration range of the reference solutions for the analyte. Introduce the sample into the atomizer,
record the reading and rinse the sample introduction system with water. Repeat this sequence twice.
Determine the element concentration from the analytical curve using the average of the three readings.
Standard addition method (Method II): add to at least four volumetric flasks equal volumes of the
solution of the substance to be determined prepared as indicated in the monograph.. To the flasks,
except for one, add determined volumes of the specified reference solution in order to obtain a series
of solutions containing increasing amounts of the analyte. Adjust volume of each flask with water
and homogenize. After calibrating the spectrometer with water, record the readings for each solution
three times. Plot the analytical curve for the mean of the absorbances of the three readings for each
solution versus the respective amount of analyte added to the solution. Record the amount of analyte
in module in the sample by extrapolating the analytical curve on the abscissa axis.
INTERFERENCES
Physical Interferences: Using sample preparation with physical properties such as viscosity and
surface tension different from the standard preparation may result in differences in relation to
aspiration and nebulization, leading to incorrect readings. Whenever possible, preparations with the
same physical properties and matrix constituents should be used.
Ionization interference: normally occurs for alkaline and alkaline earth elements that are easily
ionizable. The greater the degree of ionization, the lower the absorbance. To minimize ionization
interference, it is possible to use flames with lower temperatures or use "ionization suppressors",
which are elements such as cesium that ionize more easily than analyte, thus increasing the number
of atoms in the ground state .
Chemical interferences: the formation of thermally stable compounds in the flame, such as the oxides
of some elements (Ca, Ti, Cr, V, Al, etc.), reduces the population of atoms in the ground state. This
can be resolved by increasing the flame temperature, which results in the dissociation of these
compounds. Another possibility is the use of a “suppressor agent” or “release agent” that has greater
affinity for oxygen than the analyte, preventing the formation of oxides. The solution containing
cesium chloride and lanthanum chloride, “Schinkel' solution”, is the most commonly used.
Spectral interferences: occur through the absorption or scattering of selected radiation for the analyte.
Spectral interferences caused by atoms are uncommon and can be resolved by changing the spectral
line used. Interferences caused by molecular species are more severe, but are usually overcome by
background correction.
acidic medium, with a reductant (NaBH4). The transport of the hydrides from the reaction flask to the
quartz cell is done by an inert carrier gas, such as argon or nitrogen. For elements that absorb at a
wavelength lower than 200 nm, before the hydride generation step, a purge must be carried out to
remove atmospheric gases in order to prevent these gases from absorbing the radiation from the
source. Atomization is done in an electrically heated quartz cell or with a burner typical of flame
atomization systems; the internal temperature of the cell is from 850°C to 1000°C. The signal
obtained is normally of the transient type; about 20 seconds are required for full signal integration for
almost all elements.
INTERFERENCES
Influence of the oxidation state: analytes usually have more than one oxidation state. Arsenic and
antimony, for example, have oxidation states III and V, whereas selenium and tellurium have
oxidation states IV and VI, respectively. Higher oxidation states are generally inert for conversion to
volatile hydrides; therefore, pre-reduction is necessary before determination in these cases.
Hydride-forming elements: Mutual interferences can occur between the hydride-forming elements,
such as between arsenic and selenium. In these cases, the volatilization and atomization kinetics are
decisive in the process.
Transition elements: some metallic ions such as Cu2+ and Ni2+, if present in high concentrations, are
reduced, forming precipitates that can adsorb volatile hydrides.
Atomic absorption spectrometry with cold vapor generation is used for the determination of mercury.
The apparatus and reagents are the same used in the hydride generation system, but the quartz cell
does not need to be heated, as the mercury is reduced to metallic mercury, which is volatile at room
temperature. However, water vapor can be transported by the carrier gas and interfere with the
determination. To solve this problem, an infrared lamp is used to heat the quartz cell, preventing the
condensation of water vapor. In this case, it is usually not necessary to carry out the purge, as the
wavelength used for the determination of Hg is 253.7 nm, in which the absorption of radiation by
gases from the atmosphere is rare.
Analysis with the graphite furnace can be divided into the following steps: sample drying, pyrolysis,
atomization and cleaning. The transition from one step to another is marked by the increase in
temperature, therefore, a special heating program must be planned. First, the sample is dried; in this
step the residual solvents and acids are evaporated. After drying, the temperature is risen to remove
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.13-00
the matrix (pyrolysis step). Then, the increase in temperature leads to atomization of the analyte for
further quantification. Finally, the furnace is cleaned at a high temperature (e.g. 2600 °C) for a few
seconds. The temperature and duration of each heating step can be controlled; this is essential for
developing analytical methods.
Atomization and pyrolysis curves are used to optimize temperatures for such processes. The pyrolysis
curve allows determining the maximum temperature at which no loss of analyte occurs. The
atomization curve determines the minimum atomization temperature of the analyte with adequate
sensitivity. It is recommended that pyrolysis and atomization curves are made whenever an unknown
sample is analyzed.
The atomization process in a graphite furnace is complex and depends on many factors, such as the
material of the furnace and platform, the atmosphere inside the tube, the heating rate, the temperature
and nature of the substances. For best results, it is recommended to use the L’Vov platform inside the
tube as well as transversal heating. The signal obtained is of the transient type; a maximum of 12
seconds is required for signal integration.
INTERFERENCES
Spectral Interferences: Interferences caused by overlapping lines between atoms are uncommon. The
attenuation of the species radiation beam generated during the atomization process, deriving from the
matrix, is more frequent. To solve this problem, the matrix must be efficiently eliminated. The use of
a matrix modifier and background correction is essential for the reliability of the results.
Formation of volatile substances: in samples with high levels of halogens (especially Cl) there is the
possibility of formation of volatile substances from the analyte, which may be lost at low
temperatures, causing error in the analysis. In this case, the use of a chemical modifier capable of
forming thermally stable complexes with the analyte minimizes the formation of volatile substances.
Furthermore, when the chemical modifier is combined with the L’vov platform, matrix interference
effects are greatly reduced. It is important to point out that a given chemical modifier can be very
effective for some elements, whilst ineffective for others.
INTERFERENCES
The interferences that occur in flame photometry are very similar to those observed in Atomic
Absorption Spectrometry (5.2.13.1). However, spectral interferences can occur caused by the
SOLVENTS
The solvent must be selected carefully. If there is a significant difference in surface tension or
viscosity between the sample and the reference solution, variations in aspiration and nebulization
rates will occur and, consequently, significant differences in the signals produced. Thus, the solvent
used in the preparation of samples and references must be as similar as possible.
PROCEDURE
The apparatus must be operated in accordance with the manufacturer’s instructions and at the
specified wavelength. Adjust zero with the solvent. Then inject the most concentrated reference
solution and adjust to the desired sensitivity. The determinations are made by comparison with
reference solutions containing known concentrations of the analyte. Determinations can be carried
out by the Direct Calibration Method (Method I) or by the Standard Addition Method (Method II).as
described in Atomic Absorption Spectrometry (5.2.13.1).
APPARATUS
The apparatus used in inductively coupled plasma spectrometry basically consists of the signal
generator and processor. The generator consists of a plasma source and a sample introduction system
(propellant pump and nebulizer). The signal processor is comprised of optical and electronic systems
and data acquisition unit.
Plasma sources: The most common is inductively coupled plasma. The plasma is generated in a torch
that consists of three concentric tubes usually made of quartz. Gas flows, usually argon, are
maintained in the three compartments formed by the concentric tubes. In the outer compartment, the
gas is used to form the plasma. The intermediate compartment carries the auxiliary gas, which is
responsible for keeping the plasma away from the internal compartment and preventing deposition of
carbon and salts from the sample in that compartment. The internal argon flow carries the aerosol
from the sample to the center of the plasma. When a certain power (between 700 W and 1500 W) is
applied by the radio frequency generator to the induction coil, an alternating current is generated in
the coil at a frequency of 27 MHz or 40 MHz. This oscillation in the coil results in an intense
electromagnetic field at the tip of the torch. With argon flowing through the torch, a high-voltage
electrical discharge is applied to the gas generating electrons and argon ions. Electrons are accelerated
by the magnetic field and collide with more argon atoms generating more ions and electrons. The
ionization of argon continues in a chain reaction generating the plasma, which consists of argon
atoms, electrons and argon ions.
Detection system for Optical Emission Spectrometry with Inductively Coupled Plasma: all elements
present in the plasma emit radiation at the same time, therefore it is necessary to use a multi-element
detection system. Spectrometers can be simultaneous or sequential. For inductively coupled plasma
optical emission spectrometry, both sequential and simultaneous spectrometers are widely used. The
most common configuration for sequential spectrometers is the Czerny-Turner. Simultaneous
spectrometers, on the other hand, are basically found with Echelle and Paschen-Runge configurations.
INTERFERENCES
The overlapping of emission lines is one of the main interferences for inductively coupled plasma
optical emission spectrometry. This type of interference can be eliminated using high resolution
spectrometers and background correction procedures. Many spectral interferences are observed in the
200 nm to 400 nm range, in which more than 200.000 atomic emission lines and molecular bands are
observed.
The physical interferences are similar to those in Flame Atomic Absorption Spectrometry (5.2.13.1.1).
SOLVENTS
The ideal solvent for inductively coupled plasma optical emission spectrometry interferes as little as
possible in the emission processes. The solvent must be carefully selected. If there is a significant
difference in surface tension or viscosity between the sample and the reference solution, variations in
aspiration and nebulization rates will occur and, consequently, significant differences in the signals
produced. Thus, the solvents used in the preparation of samples and reference solutions should be as
similar as possible.
PROCEDURE
The apparatus must be operated in accordance with the manufacturer’s instructions and at the proper
wavelength for each element. The determinations are carried out by comparison with reference
solutions containing known concentrations of the analytes. Determinations can be carried out by the
Direct Calibration Method (Method I) or by the Standard Addition Method (Method II).as described
in Atomic Absorption Spectrometry (5.2.13.1).
APPARATUS
(760 Torr) to the mass separator (10-6 Torr) is done by reducing the pressure through vacuum
application. The interface consists of two metallic cones with very small orifices (of 1 mm in
diameter). After the ions are generated in the plasma, they pass through the first cone (sampling cone)
and then through the second cone (skimmer). After the passage of ions through the skimmer, due to
expansion, there is a need for them to be focused to ensure their arrival at the mass analyzer. The ions
are focused by the action of an ionic lens or set of ionic lenses, which consists of a hollow metal
cylinder (or series of cylinders or perforated plates) subjected to a potential difference (usually in the
range of 2 to 15 V of continuous current). Most of the inductively coupled plasma mass spectrometers
on the market today use the quadrupole as a mass separator. The quadrupole consists of four
cylindrical or hyperbolic metal bars of the same length and diameter. By the combined application of
direct current (dc) and alternating current (ac) to the electrodes (quadrupole), only ions with a given
mass/charge ratio (m/z) are conducted through the quadrupole. The remaining ions collide with the
electrodes or are removed from the interior of the quadrupole. Accordingly, the ions are sequentially
separated by the quadrupole. Various types of detectors can be used to collect the ions at the
quadrupole output and convert them into an electrical signal, but the most popular are discrete
dynodes, Faraday Cup and Chaneltron.
INTERFERENCES
Similar to other spectrometric methods, inductively coupled plasma mass spectrometry has spectral
and non-spectral interferences. Spectral interferences are species-dependent and can be divided into
four main types: polyatomic, isobaric, double-charged ions and refractory oxide ions. This type of
interference can be corrected by simulating the matrix composition, choosing another isotope (when
possible) or using a reaction and/or collision cell. In some cases, spectral interference can be corrected
using an appropriate computer program.
Non-spectral interferences can arise for several reasons: deposition on the interface cones, presence
of another easily ionizable element, space charge effect, among others. However, most non-spectral
interference can be corrected by using an internal standard. In this case, the internal standard must
have a mass/charge ratio and ionization potential similar to the analyte. Scandium and Rhodium, for
example, are widely used as an internal standard for elements with low and high mass/charge ratios,
respectively.
SOLVENTS
The ideal solvent for inductively coupled plasma mass spectrometry interferes as little as possible in
the emission processes. The solvent must be carefully selected. If there is a significant difference in
surface tension or viscosity between the sample and the reference solution, variations in aspiration
and nebulization rates will occur and, consequently, significant differences in the signals produced.
Thus, the solvents used in the preparation of samples and reference solutions should be as similar as
possible.
PROCEDURE
The apparatus must be operated in accordance with the manufacturer’s instructions and at the proper
isotope for each element. Adjust the zero with the solvent injected into the apparatus. The
determinations are carried out by comparison with reference solutions containing known
concentrations of the analytes. Determinations can be carried out by the Direct Calibration Method
(Method I) or by the Standard Addition Method (Method II) or by the Internal Standard Method
(Method III).
Direct Calibration Method (Method I). Prepare at least four reference analyte solutions, covering the
range of concentrations recommended by the equipment manufacturer for the elements under
analysis. All reagents used in the sample solution must be equally included, at the same
concentrations, in the preparation of the reference solutions. After calibrating the apparatus with
solvent, inject each of the reference solutions three times and, after stabilization of the reading, record
the result, washing the system with the solvent after each injection. Plot the analytical curve, plotting
the average of the readings for each group of three, with their respective concentration. Prepare the
solution of the substance to be determined as indicated in the monograph, adjusting its concentration
so that it is within the range of concentrations of the reference solutions. Introduce the sample into
the apparatus, record the reading and wash the system with solvent. Repeat this sequence twice and,
by adopting the average of three measurements, determine the analyte concentration using the
analytical curve.
Standard Addition Method (Method II).. Add to each of four similar volumetric flasks minimum,
equal volumes of prepared solution of the substance to be determined
as indicated in the monograph. Add to all, but one, flasks measured volumes of the specified reference
solution in order to obtain a series of solutions containing increasing amounts of analytes.
Conveniently dilute the volume of each flask with water. After calibrating the spectrometer with
water, as indicated above, record the readings for each solution three times.
Internal Standard Method (Method III). Prepare at least four reference analyte solutions, covering the
range of concentrations recommended by the equipment manufacturer for the analytes. All reagents
used in the sample solution must be equally included, at the same concentrations, in the preparation
of the reference solutions. The internal standard must be added to all solutions (solvent, reference
solutions and samples), with a fixed concentration and in the same order of magnitude as the analytes.
After calibrating the apparatus with solvent, inject each of the reference solutions three times and,
after stabilization of the reading, record the result, washing the system with the solvent after each
injection. Plot the analytical curve, plotting a graph of the ratio between the mean of the reading
intensities of each group of three and the intensity of the internal standard, with the respective
concentration. Prepare the solution of the substance to be determined as indicated in the monograph,
adjusting its concentration so that it is within the range of concentrations of the reference solutions.
Introduce the sample into the apparatus, record the reading and wash the system with solvent. Repeat
this sequence twice and, by adopting the average of three measurements, determine the analyte
concentration using the analytical curve.
ELECTROMAGNETIC RADIATION
Electromagnetic radiation is a form of energy that propagates as waves and can generally be
subdivided into regions of characteristic wavelength. Still, it can also be considered as a flux of
particles called photons (or quanta). Each photon contains a certain energy whose magnitude is
proportional to frequency and inversely proportional to wavelength. The wavelength (l) is usually
specified in nanometers, nm (10-9 m), and in some cases in micrometers, µm (10-6m). In the case of
infrared, electromagnetic radiation can also be described in terms of wave number and expressed in
cm-1. The electromagnetic energy wavelength ranges of interest for spectrophotometry are described
in Table 1.
ENERGY-MATTER INTERACTION
The total energy of the molecule involves the energy derived from vibration (vibrational energy, due
to the relative motion of the constituent atoms or groups of atoms in the molecule); from rotation
(rotational energy, due to the molecule rotation around an axis) and, usually, from electronic energy,
generated by the configuration of electrons in the molecule.
Molecules when absorbing energy undergo a transition to a higher energy state or excited state. The
transition to the excited state is not continuous in nature, generally taking place in stages called
transitions. In the ultraviolet and visible region, transitions are electronic and occur in portions of the
molecule called chromophores. These transitions comprise promotions of electrons from occupied
molecular orbitals, usually σ and π bonding and non-bonding, to the next higher energy orbitals, non-
bonding π* and σ*.
In the mid-infrared region (MIR), only vibrational energy transitions occur because the radiation in
this region is insufficiently energetic to promote electronic transitions. Infrared radiation-induced
vibrations comprise stretching and tensioning of inter-atomic bonds and modification of bond angles.
Near infrared (NIR) spectra are characterized by the absorption of radiation by overtones and
combination of fundamental vibrational modes of bonds such as C-H, N-H, O-H and S-H. The bands
of a NIR spectrum are generally weaker than the bands of the MIR spectrum. Chemical and physical
information, with qualitative and quantitative characteristics, can be obtained from the NIR spectrum.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.14-00
However, direct comparison between the spectrum of the sample and the reference chemical is not
recommended.
NIR spectrophotometry is widely used for physical and chemical analysis, such as: quantification and
identification of active principles and excipients, identification of crystalline and polymorphic forms,
determination of particle size, disintegration pattern and process control.
Spectra can be obtained using different acquisition modes. In the case of UV/VIS spectrophotometry,
the main mode is transmission. In NIR and MIR spectrophotometry the spectra can be acquired using
the transmission and reflection mode. The latter is subdivided into diffuse reflection and attenuated
total reflection. There is also the possibility of combining transmission and reflection modes, called
transreflectance.
Transmission: is the measure of the decrease in radiation intensity at certain wavelengths when
radiation passes through the sample. The sample is placed in the optical beam between the source and
the detector. Transmission (T) can be calculated by the formula below:
𝐼
𝑇=
𝐼0
𝐼0
𝐴 = 𝑙𝑜𝑔10 ( )
𝐼
Diffuse reflection: is the measure ratio of the intensity of the light reflected by the sample and the
light reflected by a reflective reference surface. Unabsorbed radiation is reflected towards the
detector.
Attenuated total reflection: infrared radiation propagates inside an element with internal reflection
(high refractive index) through reflections on the walls of this element. The sample is placed in
contact with the wall of this reflection element where it interacts with infrared radiation (evanescent
wave).
Spectrophotometers used in the ultraviolet and visible regions are fundamentally equipped with a
radiation source; wavelength selector; absorption cells (cuvettes) for inserting sample solutions into
the monochromatic light beam; radiant energy detector and a signal reading and processing unit.
The lamps most used as a source of radiation in spectrophotometry in the ultraviolet and visible region
are deuterium and tungsten, which provide radiation between 160 and 380 nm and 320 and 2500 nm,
respectively. Instruments for the UV/VIS regions are usually equipped with one or more devices to
restrict the radiation being measured within a narrow range that is absorbed or emitted by the analyte.
Most devices uses a monochromator or filter to isolate the desired wavelength band, so that only the
band of interest is detected and measured. Monochromators generally have a diffraction grating, while
filters can be interference or absorption filters. Photometers or colorimeters are simpler instruments
that use a filter to select the wavelength and are generally used in the visible region.
Spectrophotometers, in turn, use monochromators for wavelength selection and are used in the
UV/VIS regions.
The compartments used to receive the sample are called cuvettes, which must have windows that are
transparent in the spectral region of interest. For the UV region, quartz cuvettes are required, whereas
for the VIS region, glass or acrylic cuvettes can be used.
The main types of detectors are phototubes, photodiode arrays and charge transfer devices.
Phototubes are the simplest detectors and their answer is based on the photoelectric effect. The diode
array detector allows all wavelengths to be monitored simultaneously. Charge transfer devices have
been increasingly used in spectroscopic instruments.
Spectrophotometers may have graphic records that allow the acquisition of absorption spectra. This
feature is important for the purpose of characterizing the substance from obtaining the wavelengths
where the highest absorbances are obtained (λmaximum). Currently, most spectrophotometers are
connected to a microcomputer and an appropriate program, which allows obtaining the absorption
spectra of substances in digital media.
The spectrophotometers used to acquire mid and near infrared spectra consist of a light source,
monochromator or interferometer and detector, and allow the acquisition of spectra in the region
between 750 to 2500 nm (13 300 to 4000 cm-1).
Currently, mid-infrared spectrophotometers (4000 to 400 cm-1) use the interferometer instead of the
monochromator and the polychromatic radiation falls on the sample, with the spectra being obtained
in the frequency domain with the aid of the Fourier transform.
Transmission cells, diffuse reflection and attenuated total reflection tools are the most common
accessories for spectra acquisition.
Near infrared spectrophotometry (NIR) is a method that allows the acquisition of spectra in the region
between 13300 and 4000 cm-1 (750 to 2500 nm). The spectrophotometers in the NIR region consist
of an appropriate radiation source, monochromator or interferometer and detector. Conventional
cuvettes, optical fibers, transmittance cells and accessories for diffuse reflectance are the most
common accessories for spectra acquisition.
IDENTIFICATION BY SPECTROPHOTOMETRY
The identification of several pharmaceutical substances can be done using the ultraviolet, visible,
mid-infrared and near-infrared regions.
In general, spectrophotometry in the UV/VIS regions requires solutions with a concentration in the
order of 10 mg mL-1of the substance, while for MIR and NIR, concentrations in the order of
100 mg mL-1 are required. Despite being more sensitive, the spectra obtained in the UV/VIS regions
have less specificity when compared to the spectra in the MIR region. In the case of MIR,
measurements performed using the reflection modes (diffuse and total attenuated) provide spectral
information equivalent to that obtained by the transmission mode. When possible, a comparison of
the obtained spectrum against the spectrum of the reference chemical should be made.
Several monographs include ultraviolet absorption spectra as proof of identification. In these cases,
the scan length, solvent, solution concentration and cuvette thickness (optical path) will be specified.
Some drugs require the use of reference standards. Standard and sample readings are taken
simultaneously and under identical conditions for wavelength, cuvette size, etc.
For characterization using UV/VIS spectrophotometry, the drug is dissolved using appropriate
solvent. Many solvents are suitable, including water, alcohols, ethers and dilute acid and alkaline
solutions. It must be verified if the solvents do not absorb in the spectral region being used.
Mid-infrared (MIR)
The MIR spectrophotometry is an identification test par excellence, being able to differentiate
substances with structural differences. Of the three infrared regions (near, medium and far), the region
between 4000 and 400 cm-1 (mid infrared) is the most used for identification purposes.
The transmission spectra of solid samples are obtained by dispersing them in mineral oil or by
preparing potassium and sodium halide losenges. Sample dispersions are prepared by grinding about
5mg of the substance in a drop of spectroscopic grade mineral oil. The paste obtained is spread
between two windows of potassium bromide or sodium chloride. To prepare the losenges,
approximately 1mg of the sample is ground with approximately 300mg of spectroscopic grade
potassium bromide.
For solid powder samples opaque to the transmission of infrared radiation, the spectrum can also be
acquired by using an accessory for diffuse reflection. In this accessory, infrared radiation is directly
incident on the powdered sample. Part of the radiation is absorbed and then diffusely reflected towards
the detector. In this case, the sample in powder form is mixed with potassium bromide at a
concentration of approximately 5% (w/w) and placed in the diffuse reflection accessory.
Finally, the spectrum of solid powder and creamy samples can be obtained using a total reflection
attenuation accessory. The sample in powder form is placed under the high refractive index crystal
where it comes into contact with infrared radiation, not requiring prior sample preparation.
UV/VIS spectrophotometry
Quantitative spectrophotometric analysis by absorption is based on the direct relation between the
amount of light absorbed and the concentration of the substance, also known as Beer's law.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.14-00
When concentration (c) is expressed in mole. L-1 and the optical path (b) in centimeters, the formula
is:
A=εbc
where
Knowing that transmittance is the quotient between the intensity of the radiation transmitted by the
solution (I) and the intensity of the incident radiation (I0),you have:
log10 (I0/I) = A = ε b c
A (1%, 1 cm) = A / b c
where A(1%, 1 cm) corresponds to the absorbance of the solution at 1% (w/v) of the substance when
the optical path is 1 cm. To avoid possible deviations from Beer's law, one should try to work with
diluted solutions (in the order of 0.01 M), avoiding associations between molecules, and with
monochromatic radiation.
Quantification by means of NIR spectrophotometry can be performed using data obtained from a
reference method or from a calibration set with samples of known composition. Spectra can be
obtained using the transmission and reflection modes with the aid of suitable tools. Firstly, the spectral
data are treated through mathematical transformations to reduce sources of unwanted variations
before the calibration step. The calibration process consists of building a mathematical model that
relates the spectrophotometer response to a sample property. There are a number of chemometric
algorithms that can be used for calibration. These algorithms are usually available in software and
available together with the spectrophotometer. The main calibration algorithms are: multiple linear
regression (MLR), partial least squares (PLS) and principal component regression (PCR).
The validation of a method that employs NIR spectrophotometry is similar to that required for any
analytical procedure and is generally based on chemometric methods. The main parameters to be
evaluated are: specificity, linearity, working range, accuracy, precision and robustness.
The extent of specificity is dependent on the procedure used. The demonstration of the specificity of
the NIR methods can be done in the following manners: (i) the wavelengths used in the calibration
models must correspond to the bands of the analyte of interest; (ii) for calibration using PLS the
coefficients must be plotted and the regions with the highest coefficient compared with the analyte
spectrum; (iii) variations in the sample matrix should not significantly affect analyte quantification.
Validation of the NIR method linearity involves demonstrating its linear response for samples
distributed over a defined calibration range. The correlation coefficient, r, is not an adequate tool for
checking linearity, but it is the measure of data variation that is properly modeled by the formula. The
best method to demonstrate the linearity of the NIR methods is through the statistical evaluation of
the slope and intercept values obtained for the validation set.
The working range of the reference values for the analyte of the validation set defines the working
range of the NIR method. Controls must be established to ensure that results out of the working range
are not accepted. The validation of a NIR method should generate an anomalous value when a sample
containing the analyte outside the working range is analyzed.
The accuracy of a NIR method is demonstrated by correlating NIR results with the reference method
data. Furthermore, the accuracy can be verified from the proximity of the standard error of prediction
(SEP) with the error of the reference method. Reference method error must be known based on
historical values. Different statistical methods can be used to verify statistical differences between
the results obtained by the NIR method and the reference method.
The precision of a NIR method expresses the agreement between a series of measurements obtained
under predetermined conditions. There are two levels of precision that can be considered:
repeatability and intermediate precision. The precision of a NIR method is typically expressed as a
coefficient of variation.
The robustness of the NIR method can be verified through changes in method parameters, such as:
environmental conditions, sample temperature, sample characteristics and instrumental changes.
The intensity of light emitted by a fluorescent solution is, under certain conditions, proportional to
the concentration of the solute and, therefore, used for analytical purposes. Fluorescence intensity
measurement cannot be used directly for the determination of analyte concentration. Therefore, the
determination is made by comparing the fluorescence intensity obtained for a sample solution with
standard solutions, whose concentrations are known. The foundation of spectrofluorescence consists,
therefore, in exciting the substance with radiation at the maximum absorption wavelength and
comparatively measuring the intensity of the fluorescent light emitted against a standard.
DEFINITIONS
Fluorescence excitation spectrum: graphical representation of the activation spectrum, showing the
intensity of the radiation emitted by the activated substance (ordinate) and the wavelength of the
incident excitatory radiation (abscissa).
EQUIPMENT
The determination of fluorescence intensity can be carried out in a simple filter fluorimeter
(fluorimeter), in adapted absorption spectrophotometers or in a fluorescence spectrophotometer
(spectrofluorimeter).
The filter fluorimeter comprises light source, primary filter, sample chamber, secondary filter and
detection system. In this type of fluorimeters, the detector is arranged at 90° to the incident light. Such
a right-angle arrangement allows incident light to pass through the sample solution without interfering
with the fluorescent signal captured by the detector. This mechanism does not prevent part of the
scattered light from reaching the detector due to the diffusing properties inherent to the solutions or
due to the presence of suspended solid particles. This residual dispersion is controlled using filters.
The primary filter selects the appropriate wavelength radiation to excite the sample whereas the
secondary filter selects the longer wavelength fluorescent radiation, blocking the access of the
scattered radiation to the detector.
Most filter fluorimeter detectors are equipped with photomultiplier valves, although there are
differences between types of apparatus regarding the spectral region of maximum sensitivity. Once
the electric current generated in the photomultiplier is amplified, a corresponding reading is obtained
in an analog or digital instrument.
Fluorescence spectrophotometers, in turn, differ from fluorimeters in that they do not have filters but
rather prism monochromators or diffraction gratings, providing greater wavelength selectivity and
flexibility.
Both fluorimeters and fluorescence spectrophotometers allow the use of different light sources.
Mercury or tungsten lamps, although common, are advantageously replaced by the high-pressure
xenon arc lamp, as it provides, unlike the others, a continuous spectrum from ultraviolet to infrared.
In any case, radiation is very intense and should never be observed with the eyes unprotected, under
the risk of permanent damage.
Monochromators, in turn, have slit width adjustment. Narrow slits provide greater resolution and less
spectral noise while wide slits ensure greater light intensity to the detriment of these characteristics.
The slit width to be adopted depends on the difference between the wavelengths of the incident and
emitted light, as well as the level of sensitivity necessary for the analysis.
The sample chamber generally allows the use of round tubes and square cuvettes, similar to those
employed in absorption spectrophotometry, except for the fact that the four vertical walls must be
polished. Sample volumes of 2 to 3 mL are adequate, although some instruments may have small
cuvettes, with a capacity of 0.1 to 0.3 mL, or even holders for capillaries that require even smaller
volumes.
Apparatus calibration
Fluorimeters and spectrofluorimeters must be calibrated with stable, fluorophore substances to ensure
reproducible results. Variations are generally due to changes in lamp intensity or sensitivity of the
photomultiplier tube. The fluorophore can be the pure sample of the substance to be analyzed or any
other fluorescent substance that is easily purified, whose wavelengths of absorption and fluorescence
are similar to those of the substance being analyzed. For example, quinine in 0.05 M sulfuric acid is
a suitable standard for blue fluorescence. On the other hand, fluoresce in 0.1 M sodium hydroxide is
suitable for green fluorescence and rhodamine is the fluorophore of choice in red fluorescence. The
fluorescence spectrophotometer wavelength scale also requires periodic calibration.
PREPARATION OF SOLUTIONS
The choice of solvent used to prepare fluorescent solutions requires precautions. The nature, purity
and pH of the solvent are relevant parameters in the intensity and spectral distribution of fluorescence.
As a result, it is recommended to comply with the volume specified in established methods. Many
substances fluoresce in organic solvents but are practically non-fluorescent when dissolved in water.
Thus, experimentation in various solvents is required to determine the fluorescent property of a
substance.
For quantitative purposes, it is essential that the fluorescence intensity maintains a linear relation with
the sample concentration within limits compatible with the method. If the solution is very
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.15-00
concentrated, a significant part of the incident light will be absorbed in the periphery of the cuvette
and the amount of radiation reaching the central region will be lower. This means that the substance
itself will act as an “internal filter”. However, this phenomenon is rare, considering that fluorescence
spectrophotometry is a highly sensitive method, allowing the use of solutions with concentrations in
the order of 10-5 to 10--7 M.
Due to the usually narrow concentration limits in which the fluorescence is proportional to the
concentration of the substance, the rule is to obey the ratio (c-d)/(a-b) = 0.40 to 2.50. In this case, a
is the fluorescence intensity of the reference solution, b is the intensity of the corresponding blank, c
is the intensity of the sample solution, and d is the intensity of the corresponding blank.
Fluorescence determinations are sensitive to the presence of solid particles in the solutions. Such
impurities reduce the intensity of the incident beam, producing false high readings due to multiple
reflections in the cuvette. It is therefore necessary to eliminate these solids by centrifugation or
filtration prior to reading, bearing in mind, however, that some filter papers may contain fluorescent
impurities.
The presence of dissolved oxygen in the solvent exerts a dampening effect on the fluorescence
intensity and it should be eliminated using, for example, passage of a current of nitrogen, helium or
any inert gas in the solution, prior to the reading.
Temperature control is also important. In some substances, the fluorescence emission can decrease
by 1 to 2% with each temperature increase of 1°C. Accordingly, when maximum precision is required,
the use of thermostatic cuvettes is recommended. However, for routine analysis, there is no need for
this resource as long as the determinations are made quickly enough to avoid heating due to exposure
of the solution to bright light.
Some fluorescent substances are sensitive to light and, when exposed to intense light radiation from
the fluorescence spectrophotometer, they can decompose into more or less fluorescent products. This
effect can be detected by observing the detector's response in relation to time and attenuated by
reducing the incident light intensity using filters.
In turbidimetry, also known as opacity, the intensity of light transmitted in the same direction as the
incident light is measured. Although there are turbidimeters specifically designed to measure
turbidity, conventional colorimeters and spectrophotometers are satisfactory for measuring
transmitted light as long as they are adjusted to the appropriate wavelength.
Nephelometry (or diffusimetry), in turn, comprises the measurement of the intensity of light scattered
(reflected) by suspended particles, at a right angle to the incident light beam. Once again, in addition
to nephelometers, it is possible to use colorimeters and spectrophotometers in nephelometric
measurements. Therefore, it is necessary to modify them so as to allow the capture perpendicular to
the angle of the incident light, either by transferring the light source or by changing the position of
the detector. Fluorimeters, similar to nephelometers, are used to measure scattered light (positioning
the detector at an angle of 90º in relation to the incident light) and are therefore compatible with
nephelometry.
Turbidity
Turbidance (S) in analogy to transmittance (T), defined in UV, Visible and infrared absorption
spectrophotometry (5.2.14) is the official expression of light scattering produced by suspended
particles, determinable by turbidimetry or nephelometry, according to the formula
𝑃0 𝑏𝑑3
𝑠= 𝑘 4
𝑃 𝑑 + 𝜆4
where
A suspension evaluated in a given instrument, under monochromatic light, presents turbidity that
corresponds to the product of concentration C by a constant of proportionality k, which combines the
other parameters of the formula above. Therefore, S = kC, expression of the Lambert-Beer law,
allowing turbidimetric and nephelometric procedures to be analogous to those adopted in
spectrophotometry. It is, however, relevant to note that proportionality is only true for very dilute
suspensions, as secondary reflections cause excessive linearity deviation when the number of
suspended particles exceeds a certain limit.
incorporation of protective colloid – gelatin, gum arabic or starch – in the liquid medium of the
suspension.
PROCEDURE
The basic procedure for the use of turbidimetric or nephelometric methods follows the principles of
spectrophotometric methods, comprising the preparation of reference suspensions of known
concentration. In practice, plotting against transmittance values rather than turbidity is allowed.
The steps of the procedure comprise, briefly: (1) adjust the instrument to the wavelength specified in
the monograph (for colorimeters, in the absence of specification, use a filter that provides light in the
blue range); (2) fill the cuvette with the most concentrated suspension and adjust the transmittance
reading to 100% (transmittance offers more linearity than absorbance); (3) measure the transmittance
of the other standard suspensions and plot the calibration curve (using the least squares method) and
(4) measure the transmittance of the sample, determining its concentration using the calibration curve.
Visual comparison
Turbidity measurements can be performed by visual comparison, a method in which the suspension
of the sample is compared with suspension or standard suspensions. To do so, use identical test tubes,
flat-bottomed, with a capacity of 70 mL and approximately 23 mm in internal diameter. Tubes must
be compared horizontally on a dark background, with lateral light incidence.
5.2.17 CHROMATOGRAPHY
The apparatus used for thin layer chromatography consists of: plate, tank or elution chamber,
stationary phase, mobile phase, TLC visualization reagent system. Plates are usually made of glass,
aluminum or plastic material. Sizes vary as follows: 20 cm x 20 cm; 10 cm x 20 cm; 10 cm x 10 cm;
5 cm x 10 cm.
Silica – It is the most widely used adsorbent in TLC. It is an amorphous and porous adsorbent. It is
also used in column chromatography; however, the silica used in TLC is thinner. Silica is prepared
by spontaneous polymerization and dehydration of silicic acid. The substances are adsorbed by silica
via hydrogen bonding and dipole-dipole interaction. A silica of satisfactory condition is one with 11
to 12% water by weight. A moisture level of 11 to 12% is achieved when the silica is in equilibrium
with air, at a relative humidity of 50% and a temperature of 20°C.
Commercial silicas have variable pore sizes, between 40 and 150 Angstroms. Particle sizes range
from 5 to 40 μm, averaging 10 to 15 μm, depending on the manufacturer.
By reducing the particle size, the silica performance is increased. Particle sizes from 5 to 6 µm are
used to prepare HPTLC (High Performance Thin Layer Chromatography). Pore sizes affect
selectivity and therefore can be used for migration rates and resolution of sample components.
The most common commercially available silica pore sizes are 40, 60, 80 and 100 Angstroms, with
60 Angstrom silica being the most versatile and widely used. Silica are used for the separation of
lipophilic compounds, such as aldehydes, ketones, phenols, fatty acids, amino acids, alkaloids,
terpenoids and steroids, using the adsorption mechanism.
Alumina – After silica, it is the most used adsorbent. The physical properties of alumina are similar
to those of silica in terms of particle size, average pore diameter and surface. Acid (pH 4.0 –4.5),
neutral (7.0 –8.0) and basic (9.0 –10.0) alumina are commercially available. Similarly to silica,
alumina separates sample components by polarity, through hydrogen bonds, Lewis acid-base
interactions or dipole-dipole interactions. The selectivity of alumina in adsorption TLC is similar to
silica gel, with alumina being a better adsorbent than silica for the separation of lipophilic acid
substances. Alumina with an acidic character strongly attracts basic substances, whereas alumina with
a basic character attracts more strongly acidic substances. Alumina retains aromatic substances more
strongly than silica gel. It has the inconvenience of promoting the catalysis of some reactions of labile
substances. It is used in the separation of fat-soluble vitamins, alkaloids, certain antibiotics and
polycyclic hydrocarbons.
Kieselguhr – It is the thermally treated Diatomaceous Earth, with a granulation of 5 to 40 μm. Its
main constituent is SiO2. A variety of other inorganic compounds are also present. Pore sizes vary
greatly, its characteristics make it suitable for separating sugars, amino acids and other similar polar
substances.
Polyamide – In contrast to cellulose, polyamide is a synthetic resin. Two types of polyamide are
used: polyamide 6 and polyamide 11. Polyamide 6 comes from aminopolycaprolactam, whereas
polyamide 11 is prepared from polyaminoundecanoic acid. Polyamides are used for the separation of
polar compounds that are able to interact with the amide group by hydrogen bonds due to their
molecular structure. Among them there are amino acids and derivatives, benzodiazepines, carboxylic
acids, cyclodextrins, fatty acids, flavonoids, preservatives and pesticides.
Magnesium silicate – ideal for the separation of sugars, anthraquinones, flavones, glycosides,
steroids, lipids, pesticide residues, vitamins, carbazoles, hydrocortisone acetate.
After the development of chromatography and evaporation of the solvents, the stain development
method is used. This, in turn, can be physical or chemical. As a physical method, ultraviolet light
(lamps emitting radiation between 254 and 366 nm) is commonly used in the case of substances that
become fluorescent when excited by UV or visible light. Chemical methods comprise the use of
chromogenic reagents. There is an extensive list of TLC visualization reagents suitable for each group
of substances.
Identification
The final position of each spot is designated by the Rf (retention factor). After developing the
chromatoplate, the distance reached by each stain from the origin is measured. This distance is a
fraction of the total distance traveled by the solvent in the stationary phase.
Rf = (distance reached by the stain from the origin) / (distance traveled by the solvent from the origin)
In chromatographic paper, the adsorbent is a paper layer of suitable texture and thickness.
Chromatographic separation occurs through the action of the liquid mobile phase similar to the
adsorption process in column chromatography. Due to the intrinsic water content of the paper, or
selective inhibition of the hydrophilic component of the liquid phase by the paper fibers, which can
be considered as stationary phase, a partition mechanism can significantly contribute to the
separation.
The chromatogram is developed by the slow passage of the mobile phase over the paper layer.
Development can be upward, in the case of solvent carried upwards by capillary forces, or downward,
in the case where the solvent flow is aided by the force of gravity.
The simplest form of paper chromatography is ascending chromatography, which uses a strip of paper
of varying length and width, depending on the chromatographic chamber being used.
This method is very useful for separating very polar substances such as sugars and amino acids. It has
the inconvenience of being able to apply a small amount of substance at a time. One should try to
work in the closest possible conditions, of quality and quantity, between standard and sample, using
the same paper, mobile phase, temperature, etc.
It consists of a glass chromatographic chamber or tank, provided with ground edges and lid and with
adequate dimensions to contain the chromatographic paper, which can be adapted for ascending or
descending chromatography. It is important that vapors from the mobile phase are not allowed to
escape.
Use special filter paper for chromatography, cut along the fibers into strips of variable length and
width of minimum 2.5 cm. There are several types of chromatography paper with different purposes
for separating hydrophilic or hydrophobic, organic or inorganic, amphoteric or with many hydroxyl
substances, among others.
For descending chromatography, use a tank with a lid provided with a central orifice, closed by a
glass stopper or other inert material. At the upper part of the chamber, there is a suspended cuvette,
which contains a device for holding the paper (usually a glass rod or stick). On each side of the cuvette
there are glass guides, which support the paper so as not to touch the walls of the chromatographic
chamber. The width of the chromatographic paper cannot be greater than that of the suspended cuvette
and the height must be approximately equal to the height of the chromatographic chamber.
For ascending chromatography, there is a device in the upper part of the chamber that allows the
chromatographic paper to be supported and that can be lowered without opening the chromatographic
chamber. Handle the paper carefully and by the edges, and cut strips into sizes that can be placed in
the chambers. It is important to cut the strips following the grain of the paper, as the cellulose is
oriented to this direction, which will facilitate the passage of the mobile phase. The strip of paper
must not touch the walls of the chamber.
When adding the paper to the chamber (paper addition should not be delayed so that there is no loss
of saturation), make sure that the sample does not come into direct contact with the eluent, allowing
it to ascend or descend on the surface of the paper, only by capillarity.
When the method used is ascending chromatography, plot a thin line with a pencil 3 cm from the
lower edge of the paper; if the chromatography is descending, plot a line at a distance, such that it is
a few centimeters below the rod that holds the paper in the eluent cuvette. The finish line of the mobile
phase (or solvent front) should also be marked, usually at a distance of 10 cm from the starting point.
Apply the solutions in the form of circular spots (capillary tubes or micropipettes are used), containing
1 to 20 µg of the sample, with each spot having a width between 6 to 10 mm over the line plotted
with a pencil. Depending on the width of the paper, only an aliquot of the standard or sample can be
placed, centering this application on the starting line. In the case of placing more than one aliquot at
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.17-00
the starting point, leave 2 cm of distance from the lateral edges and a range between the application
points of 3 cm. If each stain produced is larger than 6 to 10 mm, apply the sample in portions, allowing
the solvent to evaporate before applying the next portion.
The level of the mobile phase must be below the starting point of the substance, and there must always
be a good sealing in the chromatographic chamber so that the vapor in this phase is not lost. At the
end of the procedure, wait for the paper to dry and submit it to some development process.
1 - SAMPLE
2 - SAMPLE Ascending paper
P-STANDARD strip
Ascending
chromatography
Descending
chromatography
FM: Mobile phase; PP Starting point; LC: Finish line; dr1 and dr2: distances covered by substances; dm: mobile phase
migration distance
DESCENDING CHROMATOGRAPHY
In descending chromatography, the mobile phase has a downward flow and relies on the action of
gravity.
Introduce a layer of eluent specified in the monograph into the chamber, cap and allow to stand for
24 hours. Apply the sample to the paper, placing it properly on the guides so that the upper end
remains inside the suspended cuvette and hold it with the glass rod. Close the chamber and allow to
stand for an hour and a half. Then, through the hole in the lid, introduce the eluent into the cuvette.
Develop the chromatogram up to the prescribed distance or time, protecting the paper from direct
light incidence. Remove the paper, mark the path of the mobile phase, dry and visualize as prescribed
in the monograph.
ASCENDING CHROMATOGRAPHY
The upward flow of the mobile phase over the chromatographic paper is allowed by capillary action.
Place the container with the eluent at the bottom of the chromatographic chamber, close the chamber
and allow to stand for 24 hours. Apply the sample to the paper, introducing it into the chamber and
allow to stand for an hour and a half. Without opening the chamber, lower the paper so that its lower
end is in contact with the eluent and develop the chromatogram up to the prescribed distance or time.
Remove the paper, mark the path of the eluent, dry and visualize as prescribed in the monograph.
EQUIPMENT
PROCEDURE
Start the preparation of the column, if necessary, sealing the bottom, at the base of the tube, close to
the tap, with a piece of cotton or glass wool in order to prevent the passage of adsorbent material and
the entry of air (avoiding formation of bubbles). Then, uniformly fill the tube (according to the
specified height) with this adsorbent material (such as activated alumina or silica gel, diatomaceous
silica or calcined silica), previously suspended in the mobile phase (solvent system), removing the
excess of eluent. After sedimentation of the adsorbent material, apply the mixture of substances
previously dissolved in a small amount of solvent, at the top of the column, until it penetrates the
adsorbent material. A certain amount of solvent can be added to the top to help adsorb the substances
onto the adsorbent material, which is then allowed to settle by gravity or by applying positive air
pressure, with the mixture being adsorbed in a narrow horizontal band at the top of the column. The
movement rate of a given substance is determined or affected by several variables, including the low
or high adsorptiveness of the adsorbent material, the particle size and surface area (contact surface),
the nature and polarity of the solvent, the pressure applied and the temperature of the chromatographic
system.
A flow chromatogram is widely used and is obtained by a process in which solvents travel through
the column until the substance is separated into an effluent solution, known as an eluate. The eluate
is controlled by collecting fractions as specified in the monograph and examining each fraction by an
appropriate method. The substance can be determined in the eluate by several methods: titration,
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.17-00
colorimetry, spectrometry or be isolated (purified) upon evaporation of the solvent. The separation
performance can be gauged by thin layer chromatography (TLC) of each fraction collected throughout
the chromatographic run.
In partition chromatography, the substances to be separated are partitioned into two immiscible
liquids, one of which, the stationary phase, is adsorbed onto a solid support, thus presenting a very
large surface area for the circulating solvent or mobile phase. The high number of serial liquid-liquid
contacts allows an effective separation, which does not occur through the usual liquid-liquid
extraction.
The solid support is generally polar, while the stationary adsorbent phase is more polar than the
mobile phase. The most used solid support consists of chromatographic siliceous earth, whose particle
size is satisfactory for proper eluent flow. In reverse phase partition chromatography, the stationary
adsorbed phase is less polar than the mobile phase, and the solid adsorbent becomes nonpolar by
treatment with a silanizing agent (e.g. dichlorodimethylsilane; paraffins) to produce a
chromatographic silanized sand.
The sample to be chromatographed is usually inserted into a chromatographic system in two manners:
(a) a sample solution in a small volume of mobile phase at the top of the column; or (b) a sample
solution in a small volume of the stationary phase is mixed with the solid support and transferred to
the column, forming a transverse layer over the adsorbent material.
Development and elution are achieved through the “run” of the circulating solvent. The solvent
(mobile phase) is usually saturated with the solvent (stationary phase) before use. In the case of
conventional liquid-liquid partition chromatography, the partition degree of a given compound
between the two liquid phases is expressed by means of the partition or distribution coefficient.
In the case of substances that dissociate, the distribution can be controlled by modifying the pH, the
dielectric constant, the ionic strength, among other properties of the two phases. Selective elution of
the mixture components can be achieved by successfully changing the mobile phase to one that
provides a more favorable partition coefficient, or by changing the pH of the stationary phase in situ
with a stationary phase consisting of an acid solution. or an appropriate base in an organic solvent.
Unless otherwise specified in the individual monograph, assays and tests employing partition column
chromatography are carried out in accordance with the conventional methods described below.
Solid support – Use purified silica sand. For reverse phase partition chromatography, use
chromatographic silica sand.
Stationary phase – Use the solvent or solution specified in the individual monograph. If a mixture of
liquids in the stationary phase is used, mix before introducing the solid support.
Mobile phase – Use the solvent or solution specified in the individual monograph. Equilibrate with
water if the stationary phase is an aqueous solution; if the stationary phase is a polar organic solvent,
equilibrate with this solvent.
specified amount of solid support in a beaker (cylinder) from 100 mL to 250 mL and mix until a
homogeneous paste is produced. Transfer the mixture to the chromatographic tube, cap, pressing
slightly, until a uniform mass is obtained. If the amount of solid support specified is more than 3 g,
transfer the mixture to the column in portions of approximately 2 g, capping each portion. If the assay
or test requires a multi-segment column, with a different stationary phase for each segment, cap after
each segment is added, and add each next segment directly to the previous one. If an analyte solution
is incorporated into the stationary phase, complete the quantitative transfer to the chromatographic
tube by washing the beaker used to prepare the test mixture with a mixture of approximately 1 g of
solid support and several drops of the solvent used for prepare the test solution. Insert a thin piece of
glass wool on top of the complete filling column. The mobile phase flows through a properly filled
column with moderate flow or, if reverse phase chromatography is used, slowly dropwise.
Transfer the mobile phase to the column space over the filled part, and allow to flow through the
column under gravity. Wet the tip of the chromatographic column with about 1 mL of the mobile
phase before each mobile phase composition change and after completing the elution. If the analyte
is introduced into the column as a mobile phase solution, allow to elute completely through the filled
column, then add the mobile phase in several smaller portions, allowing each to be completely
removed before adding the stored mobile phase.
Use ion exchange resin as stationary phase. Ion exchange consists of reversible exchange of ions
present in the solution with resin polymer ions (modified cellulose or silica gel support). The choice
of resin, strong or weak, anionic or cationic, will depend largely on the pH at which the ionic exchange
should take place and on the nature of the ions (anions or cations) to be exchanged. Strongly acidic
and strongly basic resins are suitable for most analytical applications. In practice, a large excess
(200% to 300%) of resin is used over the stoichiometrically calculated sample amount; resin capacity
ranges from 2 mM/g to 5 mM/g (dry weight).
Resin treatment and column preparation – Suspend the ion exchange resin in water and allow to stand
for 24 hours. Introduce into a suitable column and, in the case of anionic resin, convert into basic by
passing through the column, sodium hydroxide RS solution, at a rate of 3 mL/minute, until the eluate
provides a negative reaction for chloride ion. Then rinse with carbon dioxide-free water. In the case
of cationic resin, the conversion to the acid form is done by passing hydrochloric acid RS through the
column, followed by washing with carbon dioxide-free water until the eluate provides a neutral
reaction.
An ion exchange column is developed similarly to that described for adsorption chromatography.
After the operation, the resin is regenerated by washing with sodium hydroxide RS (anion-exchange
columns) or hydrochloric acid RS (cation-exchange columns) and then with carbon dioxide-free
water until a neutral reaction is produced.
analysis time. Several chemical and physicochemical factors influence the chromatographic
separation, which depend on the chemical nature of the substances to be separated, on the composition
and flow of the mobile phase and on the composition and surface area of the stationary phase.
APPARATUS
The apparatus used consists of a reservoir containing the mobile phase, a pump for driving the mobile
phase through the chromatographic system, an injector to introduce the sample into the system, a
chromatographic column, a detector and a data capture device, such as software, integrator or
recorder. In addition to receiving and sending information to the detector, software is used to control
the entire chromatographic system, providing greater operability and analysis logistics.
After dissolving the sample in the mobile phase or in another suitable solvent, the solution is injected
into the chromatographic system, manually, using an appropriate syringe, or through an injector or
automatic sampler. This consists of a carousel or tray, capable of accommodating several vials
containing the samples. Some autosamplers can be programmed to inject different volumes of sample,
different amounts of injections, control the range between injections and other operational variables.
When working at high pressures, an injection valve is essential. This presents a calibrated system,
with a defined volume, called an injection ring or sampling loop, which will be filled with the solution
to be analyzed, which will later be transferred to the column.
For most pharmaceutical analyses, separation is achieved by partitioning the components, present in
the solution to be analyzed, between the mobile and stationary phases. Systems consisting of polar
stationary phases and nonpolar mobile phases are defined as normal phase chromatography, whereas
the opposite, polar mobile phases and nonpolar stationary phases, are called reverse phase
chromatography. The affinity of a substance for the stationary phase, and consequently the retention
time on the column, is controlled by the polarity of the mobile phase.
Stationary phases used in reverse phase chromatography typically consist of an organic molecule
chemically bonded to silica particles or other supports, such as porous graphite. The particle diameter
is typically 3 μm to 10 μm. The smaller the diameter of the particles and the film covering the support,
the faster and more efficient will be the transfer of substances between the stationary and mobile
phases. The polarity of the column depends on the functional groups present, the most common being
the non-polar groups octyl, octadecyl, phenyl, cyanopropyl and polar group, nitrile. The proportion
of silanol groups not linked to the functional group significantly influences the performance of
chromatographic separation and the shape of the eluted peak. Commercially, chromatographic
columns with different qualities of stationary phases are available, including those with a small
proportion of free silanol groups, called endcapped. Generally, reversed-phase silica columns have a
shelf life in the pH range of 2 to 8, however, columns containing porous graphite or polymeric
materials such as styrene-divinylbenzene are stable over a wider pH range. Less commonly, unalloyed
liquids can be used as a coating of the silica support and therefore must be immiscible with the mobile
phase. Columns commonly used for analytical separations have internal diameters from 1 mm to
5 mm. These can be heated, providing more efficient separations, but temperatures above 60°C are
rarely used, due to the potential for degradation of the stationary phase or the volatility of the mobile
phase. Unless specified in the analyte monograph, columns are used at room temperature.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.17-00
The most frequently used detectors in high performance liquid chromatography are
spectrophotometric (UV/Vis). Spectrophotometric detectors are used to detect substances with a
chromophore group. Such detectors consist of a flow cell located after the chromatographic column.
Ultraviolet radiation constantly passes through the flow cell and is received at the detector. With the
system in place, substances elute from the column, pass through the flow cell and absorb radiation,
resulting in measurable changes in the energy level. These detectors can present fixed, variable or
multiple wavelength. Fixed wavelength detectors operate on a single value, typically 254 nm, emitted
by a low-pressure mercury lamp. Those with variable wavelength contain a continuous source of
emission, such as a high pressure deuterium or xenon lamp, and a monochromator or an interference
filter, in order to generate monochromatic radiation of a wavelength selected by the operator, which
can, further, be programmed to change the wavelength during the development of the analysis.
Multiple wavelength detectors simultaneously measure absorbance at two or more wavelengths,
called diode array detectors (DAD). In these, ultraviolet or visible radiation is transmitted through the
flow cell, absorbed by the sample and then separated into their different wavelengths, which are
individually detected by the photodiode detector, recording absorbance data across the entire
spectrum range of the ultraviolet and visible and, additionally, the spectra of each peak recorded in
the chromatogram.
Refractive index detectors measure the difference between the refractive index of the pure mobile
phase and the mobile phase containing the substance to be analyzed. They are used to detect
substances that do not absorb in the ultraviolet or visible light, however, they are less sensitive than
spectrophotometric detectors. Refractive index detectors have the disadvantage of being sensitive to
small changes in mobile phase solvent composition, flow rate and temperature.
Fluorimetric detectors are used to detect compounds with a fluorophore group or which can be
converted to fluorescent derivatives, by chemical transformation or by adding fluorescent reagents to
specific functional groups. If a chemical reaction is required, it can be carried out at the time of sample
preparation or, alternatively, the reagent can be introduced into the mobile phase, with the reaction
taking place before detection.
Potentiometric, voltammetric, or electrochemical detectors are useful for quantifying substances that
can be oxidized or reduced in an electrode. These detectors are highly selective, sensitive and safe,
but require mobile phases free of oxygen and reducible metal ions. A continuous flow pump must be
used, ensuring that the pH, ionic strength, and temperature of the mobile phase remain constant.
Electrochemical detectors with specific carbon electrodes can be used, advantageously, to quantify
nanograms of easily oxidizable substances, such as phenols and catechols.
In mass spectrometry (MS) detection, the m/z ratio (mass/charge ratio) of the precursor ion of a
substance is measured. The precursor ion is generated from the substance protonation (positive
mode), from deprotonation (negative mode) or even from the formation of sodium, potassium,
formate, etc. adduct ions. The combination of mass spectrometry with liquid chromatography
provides good selectivity, since unresolved peaks can be isolated by monitoring a selected
mass/charge (m/z) ratio value. These mass spectrometers can have only one mass analyzer, such as a
single quadrupole, or sequential or tandem (MS/MS), such as a triple quadrupole, when two mass
analyzers are combined. In this case, it is possible to fragment the precursor ion in a collision cell
located before the second mass analyzer. Thus, the monitoring of the mass transitions (precursor ion
→ product ion), usually specific for each analyte, allows the analysis with high selectivity, since it is
possible to obtain a chromatogram for each mass transition. The most commonly used ionization
sources in the HPLC-MS coupling are the “electrospray ionization” (ESI) and the “atmospheric
pressure chemical ionization” (APCI) type.
Conductivity detectors have application in ion exchange chromatography and measure the
conductivity of the mobile phase continuously, which is modified in the presence of analytes in the
flow cell.
Currently, modern data collection systems are available with the functions of receiving and storing
the signals coming from the detector and, subsequently, providing the management of this
information, generating chromatograms with the peak area and height data, sample identification,
methods, among others. Information can also be collected in simple data recording systems, such as
loggers, to ensure the integrity of the generated data.
PROCEDURE
Column length and internal diameter, stationary phase particle type and size, operating temperature,
mobile phase composition and flow rate and detection type are described in the individual
monographs.
The composition of the mobile phase has a significant influence on the chromatographic performance
and on the separation of substances present in the solution to be analyzed. For accurate quantitative
analysis, high purity reagents or chromatographic purity organic solvents should be used. Water, of
adequate quality, must have low conductivity and low ultraviolet absorption. In partition
chromatography, the partition coefficient and hence the separation can be modified by adding another
solvent to the mobile phase. In ion-exchange chromatography, substance retention is affected by pH,
ionic strength, and other changes in the composition of the mobile phase. The method of continuously
modifying the composition of mobile phase solvents during the chromatographic run is called
gradient elution, and is applied to separate complex mixtures of substances with different retention
factors. However, detectors that are sensitive to changes in the composition of the mobile phase, such
as refractometers, have limited use with the gradient elution method.
The detector must have a wide linear range and the substances to be analyzed must be separated from
any interfering ones. The linear range for a substance is one in which the detector response is directly
proportional to its concentration.
HPLC systems are calibrated by comparing the peak responses obtained with the respective
concentrations of chemical reference standards (CRS). Reliable quantitative results are obtained
through calibration with an external standard, when injectors or autosamplers are preferably used.
This method involves direct comparison of the responses obtained with the separately analyzed peaks
of standard and sample solutions. In cases where external standardization is used, calculations can be
performed according to the formula:
Ca = Cp(Ra / Rp)
where
If the injection is performed by syringe, better quantitative results are obtained by means of internal
standard calibration, by adding a known amount of a non-interfering reference chemical to the
standard and sample solutions. The relation of responses obtained with the substance to be analyzed
and with the internal standard is used as a response to express the quantitative result. In cases where
internal standardization is used, calculations can be performed according to the formula:
(𝑅𝑎 / 𝑅𝑎𝑖)
𝐶𝑎 = 𝐶𝑝
𝑅𝑝 / 𝑅𝑝𝑖)
where
Rai= response (area or height) of the peak of the sample solution internal standard;
Rpi= response (area or height) of the peak of the internal standard of the standard solution;
Due to normal variations among devices, solvents, reagents and methods, a system suitability test is
required to ensure that the described method is applied unrestrictedly. The main parameters of system
suitability are described in the Interpretation of chromatograms and in System suitability.
INTERPRETATION OF CHROMATOGRAMS
Retention time (t), Retention factor (k) and Relative retention time
The retention time in chromatography is characteristic of the analyte, however it is not exclusive. The
comparison between the retention times of the peak obtained with the sample and the peak obtained
with the reference chemical can be used as an indication of the identity of the substance, but it is
insufficient to guarantee the complete characterization of the sample. Absolute retention time may
vary among devices and depending on the use of different solvents and reagents. In this sense,
comparisons are made in terms of the retention factor, k, calculated according to the expression:
𝑡 − 𝑡0
𝑘=
𝑡0
where
t = retention time of analyte;
t0 = dead time.
The retention factor, k, is the ratio between the amount of substance with affinity for the stationary
phase and the amount with affinity for the mobile phase. The greater the affinity of the substance for
the stationary phase, the greater its retention.
The concept of relative retention time can also be applied. For that, a substance, of a mixture, must
be defined as the main one. This will have a relative retention time of 1. All other substances will
have their retention times related to the retention time of the main substance.
𝑡 𝑡
𝑁 = 16 × ( ) ² 𝑜𝑢 𝑁 = 5,54 × ( )²
𝑊 𝑊ℎ/2
The value of N depends on the substance to be analyzed and the analysis conditions such as mobile
phase, temperature and stationary phase.
The peak/valley ratio can be used as a system suitability criterion in a related substance assay, when
separation between two peaks in the baseline is not sought. Figure 2 represents an incomplete
separation of two substances, where hp is the height of the smallest peak above the extrapolated
baseline, and hv is the height at the lowest point of the curve, which separates the minor and major
peaks above the extrapolated baseline.
p/v = hp/hv
Resolution (R)
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.17-00
The resolution, R, is the chromatographic parameter that indicates the degree of separation between
two substances in a mixture, and is calculated using the expressions:
2(𝑡2 − 𝑡1 ) (𝑡2 − 𝑡1 )
𝑅= 𝑜𝑢 𝑅 = 1,18
𝑊1 + 𝑊2 (𝑊1,ℎ/2 − 𝑊2,ℎ/2 )
where
t2 and t1 = retention times of the two substances in the mixture;
W1 and W2 = respective peak widths in the baseline, by the triangulation method;
W1,h/2 and W2,h/2 = respective peak widths at half height.
The area or height of the peak is usually proportional to the amount of substance eluted. The area
under the peak is generally used the most, however it may be less accurate if there are other interfering
peaks. For manual measurements, the graph must be obtained at a speed greater than usual,
minimizing errors in obtaining the width and width at half height of the peaks. For quantitative
analysis, substances must be completely separated from any interfering substances.
The tailing factor, T, which indicates the symmetry of the peak, has a value equal to 1 when the peak
is perfectly symmetric. This value increases as peak asymmetry becomes more pronounced. In some
cases, values lower than 1 may be observed. As peak asymmetry increases, integration and accuracy
become less reliable. The tailing factor is calculated using the expression:
𝑊0,05
𝑇=
2𝑓
where
W0,05
f 0,05 h
SYSTEM SUITABILITY
System suitability testing is an integral part of liquid chromatography methods. They are applied to
verify if the resolution and reproducibility of the chromatographic system are adequate for the
analyses to be carried out. The main parameters required to check the suitability of the system are
described below.
The resolution, R, is a function of column performance, N, and is specified to ensure that substances
eluting in close proximity to each other exhibit satisfactory separation without mutual interference.
Replicates of standard solution injections are statistically processed to verify that the requirements
for analysis accuracy have been met. Unless specified in the individual monograph, data from five
replicate injections is used to calculate the relative standard deviation (RSD) if the specification is
equal to or less than 2.0%. If the specified relative standard deviation is greater than 2.0%, data from
six replicates should be used.
The tailing factor, T, which indicates peak symmetry, is equal to 1 for perfectly symmetric peaks and
greater than 1 for peaks that show asymmetry. In some cases, values lower than 1 may be observed.
These tests are performed after collecting the results of replicate injections of the standard solution
or another solution specified in the individual monograph. The specification of these chromatographic
parameters, in a monograph, does not prevent the modification of the analysis conditions.
Adjustments in working conditions, in order to reach the parameters of suitability of the system, may
be necessary. Unless specified in the individual monograph, system suitability parameters are
determined from data obtained with the peak of the substance of interest. System accuracy,
demonstrated through replicates of the standard solution, must be achieved prior to injections of
sample solutions. The suitability of the system must be verified during the entire chromatographic
analysis, by injection of standard solution at appropriate time ranges. When there is a significant
change in apparatus or reagent, system suitability tests should be performed prior to sample
injections. The analysis will not be valid unless the system suitability test requirements are met.
The analytical methods presented in this pharmacopoeia have been validated and, in most
applications, are fully acceptable in terms of specificity, accuracy, precision, linearity, working range,
robustness and, where appropriate, detection and quantification limits.
However, the methods must be checked in their state of validation, considering the formulations being
analyzed, as there may be circumstances in which changes may be necessary, aiming to adapt them
to specific needs. The acceptable limits for variations in some chromatographic parameters are
presented in Table 1.
In no case are changes in the detector wavelength, changes in the qualitative composition of the
mobile phase, increases in particle size or injection volume allowed.
Flow ± 50%
Temperature ± 10°C; without exceeding 60°C
pH ± 0.2 units
Concentration of salt in a buffer ± 10%
±30% relative or ±2% absolute, minority component
Mobile phase composition (whichever is greater). In no case can it exceed 10%
absolute.
Reduction is acceptable, as long as the limit of
Injection volume quantification and accuracy of the chromatographic
system are verified.
The exchangers used can be classified into strong, medium and weak, depending on the functional
group attached to the polymer matrix. Strong ion exchangers are those that completely ionize over a
wide pH range, such as the sulfonic and quaternary ammonium group. The degree of dissociation of
weak and medium ion exchangers is pH dependent and, therefore, the capacity of these exchangers
varies as a function of pH. The carboxylic acid and polyamine group can be mentioned as an example.
This method allows electrical conductivity to be used for the detection and quantitative determination
of ions in solution after separation. Generally, ion chromatography with an anion exchange column
and conductivity detector can be used for the determination of F-, Cl- , Br-, SO42-, PO43-, I- ions, among
others. Because electrical conductivity is a property common to all ionic species in solution, the
conductivity detector has the ability to monitor all ionic species. The problem that occurs in the use
of electrical conductivity to quantify the eluted ionic species can be caused by the high conductivity
of the ions present in the mobile phase, mainly due to the sodium ion, making it impossible to quantify
other ions. This problem is overcome with the use of an eluent suppressor, positioned after the
separation column, where the eluent ions are converted into species that contribute to low or zero
conductance. Carbonic acid, resulting from cation exchange, is poorly dissociated, having a low
conductivity (baseline conductivity signal is less significant). Thus, the sensitivity for the
determination of anions can be significantly increased, by a factor of 10 times or greater, when
suppressors are used.
An ion chromatography apparatus basically consists of the same system used for HPLC. This system
consists of a high propulsion pump, an injection valve with a suitable sampling loop, a separation
column (for anion separation an anion exchange column must be used), a post-column, if necessary,
for the conversion of eluent ions in species with lower conductivity and a conductivity detector.
PROCEDURE
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.17-00
To operate the ion chromatograph, it is recommended to follow the manufacturer’s instructions. The
determinations are carried out by comparison with reference solutions containing known
concentrations of the analyte.
Mobile phase: prepare the mobile phase according to the specifications recommended by the
manufacturer of the anion exchange column used. It is recommended to use a mobile phase composed
of a mixture of carbonate and sodium bicarbonate (Na2CO3/NaHCO3), in the concentration range of
1.0 to 4 mmole/L, depending on the column used. Use the mobile phase flow recommended by the
equipment manufacturer and according to the ion exchange column used. During analyses using
conductivity detection, regenerate the chemical suppression column as recommended by the
manufacturer. It is recommended to use 0.005 mole/L H2SO4 and subsequent washing with purified
water.
Calibration: prepare at least four reference solutions of the element to be determined, covering the
concentration range recommended by the equipment manufacturer for the analyte under analysis, and
separately inject each reference solution into the apparatus, using an appropriate sampling loop. The
use of a 20 μL to 100 μL sampling loop is recommended. Record chromatograms and integrate signals
in area or peak height. Then plot the calibration curve. Prepare the sample solution as indicated in the
monograph, adjusting its concentration so that it is within the concentration range of the reference
solutions. Inject the sample into the chromatograph, record the reading and repeat this sequence three
times, taking the average of the three readings. Determine the element concentration from the
calibration curve. If the simultaneous determination of several anions is carried out, reference
solutions containing all analytes can be made.
When a vaporized constituent is driven by the carrier gas into the column, it is partitioned into the
gaseous mobile phase and the stationary phase by a dynamic countercurrent distribution process,
showing a greater or lesser retention due to sorption and desorption phenomena on the stationary
phase.
EQUIPMENT
The apparatus consists of a carrier gas source and a flow controller, an injection chamber, a
chromatographic column contained in an oven, a detector and a data acquisition system (or an
integrator or recorder). Carrier gas passes through the column with controlled flow and pressure and
goes directly to the detector.
Injector, column and detector are temperature controlled. Chromatography is carried out at constant
temperature or using a suitable temperature program. The substances to be chromatographed, both in
solution and gases, are injected, coming into contact with the carrier gas in the injection chamber.
Depending on the equipment configuration, the mixture to be analyzed must be injected directly into
the column or must be vaporized in the injection chamber and mixed with the carrier gas before
entering the column.
Once in the column, the constituents of the mixture are separated according to their different linear
retention indices, which are dependent on the vapor pressure and the degree of interaction with the
stationary phase. The retention index, which defines the resolution, retention time and column
performance in relation to the components of the mixture, is also temperature-dependent. The use of
temperature programs for the oven where the column is located has an advantage in the separation
performance of compounds that behave differently in vapor pressure.
The compounds leave the column separately, passing through a detector, which provides a response
related to the amount of each compound present. The type of detector to be used depends on the nature
of the substances to be analyzed and is specified in each monograph. Detectors are heated to prevent
condensation of eluted compounds. Detector output is given as a function of retention time, generating
a chromatogram, which consists of a series of peaks on the time axis. Each peak represents a substance
from the vaporized mixture, although some peaks may overlap. The elution time is characteristic of
an individual substance and the instrument response, measured as peak area or peak height, is a
function of the amount present.
Injectors
Direct injections of solutions is the usual mode of injection, unless otherwise indicated in the
monograph. Injection can be carried out directly at the head of the column using a syringe or an
injection valve, or in a vaporization chamber which can be equipped with a flow divider. The amount
of sample that can be injected into a capillary column without saturating it is lower compared to the
amount that can be injected into packed columns. Capillary columns, therefore, are often used with
injectors capable of dividing the sample into two fractions (split mode), a smaller one, which enters
the column, and a larger one, which is discarded. These injectors can be used without sample splitter
(splitless mode) for component analysis in smaller quantities or in traces.
Vapor phase injections can be carried out by a static or dynamic confined space (headspace) injection
system.
Static (purge and trap) confined space injection system (headspace) includes a concentration device,
through which volatile substances from the solution are dragged to an adsorbent column, kept at low
temperature, where they are adsorbed. The trapped substances are then desorbed in the mobile phase
by rapid heating of the adsorbent column.
Dynamic confined space injection system (headspace) includes a thermostatically controlled sample
heating chamber in which closed flasks (vials) containing solid or liquid samples are placed for a
specified period of time so that volatile components of the samples reach equilibrium between the
non-gas phase and the vapor phase. Once equilibrium is established, a predetermined amount of the
vial confined space is injected into the chromatograph.
Stationary phases
• a fused silica capillary column whose wall is coated with the stationary phase;
• a column packed with inert particles impregnated with the stationary phase;
• a column packed with the solid stationary phase.
Capillary columns, usually made of fused silica, have an internal diameter (Ø ) of 0.10 mm to 0.53
mm and a length of 5 m to 60 m. The liquid or stationary phase, which can be chemically bonded to
the inner surface, is a film from 0.1 μm to 5.0 μm in thickness, although non-polar stationary phases
can reach 5 μm in thickness.
The packed columns, made of glass or metal, have a length of 1 m to 3 m, with an internal diameter
(Ø ) of 2 mm to 4 mm. Stationary phases generally consist of porous polymers or solid supports
impregnated with the liquid phase reaching approximately 5% (w/w). High-capacity columns, with
the liquid phase reaching approximately 20% (w/w), are used for a wide range of substances and for
the determination of substances with low molecular weight, such as water. The required capacity
influences the choice of the solid support.
Supports for analysis of polar compounds in columns packed with a stationary phase of low polarity
and low capacity must be inert to avoid excessive peak elongation. The reactivity of support materials
can be reduced by silanization before filling with the liquid phase. Acid washed and calcined
diatomaceous earth is generally used. The materials are available in a variety of particle sizes, with
the most commonly used particles being 150 μm to 180 μm (80 mesh to 100 mesh) and 125 μm to
150 μm (100 mesh to 120 mesh).
Mobile phases
Carrier gas supply can be obtained from a high pressure cylinder or a high purity gas generator. In
both cases, the gas passes through a pressure reducing valve and the flow is metered to then enter the
injection chamber and column. Retention time and peak performance depend on carrier gas quality;
retention time is directly proportional to column length and resolution is proportional to the square
root of the column length. For packed columns, the average carrier gas flow is usually expressed in
milliliters per minute at atmospheric pressure and room temperature. Average flow is measured at the
detector outlet, either with a calibrated mechanical device or with a “bubbling” tube while the column
is at operating temperature. The linear velocity of the carrier gas through the packed column is
inversely proportional to the square root of the column inner diameter for a given flow volume. Flows
of 60 mL/minute in a 2 mm ID column and 15 mL/minute in a 1 mm ID column provide identical
linear velocities and therefore similar retention times. Unless specified in the monograph, the average
flow rate for packed columns is approximately 30 to 60 mL/minute. For capillary columns, linear
flow velocity is usually used instead of mean flow. This is determined from the column length and
retention time of a diluted methane sample using a flame ionization detector. Operating at high
temperatures, there is sufficient vapor pressure for a gradual loss of the liquid phase, a process called
bleeding, to occur.
Helium or nitrogen are generally used as carrier gases for packed columns, whereas nitrogen, helium
and hydrogen are used for capillary columns.
Detectors
Flame ionization detectors are the most used, but depending on the purpose of the analysis, other
detectors can be used, including: thermal conductivity, electron capture, nitrogen-phosphorus, mass
spectrometry, Fourier transform infrared spectrophotometry, among others. For quantitative analyses,
detectors must have a wide linear dynamic range: the response must be directly proportional to the
amount of substance present in the detector over a wide range of concentrations. Flame ionization
detectors have a wide linear range and are sensitive to most compounds. The response of the detectors
depends on the structure and concentration of the substance and the average flow of combustion, air
and carrier gas. Unless otherwise specified in the monograph, flame ionization detectors operate with
either helium or nitrogen as the carrier gas for packed columns, and with helium or hydrogen for
capillary columns.
Thermal conductivity detectors employ heated metal wire located in the carrier gas stream. When an
analyte enters the detector with the carrier gas, the difference in the thermal conductivity of the carrier
gas stream (sample gas and components), relative to a reference flow of the carrier gas without
analyte, is measured. In general, thermal conductivity detectors respond uniformly to volatile
substances regardless of their structure; however, they are considered less sensitive than the flame
ionization detector.
Electron capture detectors contain a radioactive source of ionizing radiation. They exhibit an
extremely high response to halogenated compounds and a nitro group, but low response to
hydrocarbons. Sensitivity increases with the number and atomic mass of halogen atoms.
Data processing stations connected to the output of the detectors calculate the area and height of the
peaks, and present the complete chromatograms containing the parameters from the run and the peak
data. The chromatogram data can be stored and reprocessed by electronic integration or any other
type of calculation as required. These data processing stations are also used to program
chromatographic runs.
PROCEDURE
Packed columns and capillaries must be conditioned prior to use until the baseline is stable. This must
be accomplished by operating at a temperature above that specified by the method or by repeated
injections of the compound or mixture to be chromatographed. The column manufacturer usually
provides instructions for the proper column conditioning procedure. In case of thermally stable
methyl and phenyl substituted polysiloxanes, a special sequence increases performance and
inactivity: keep the column at 250°C for one hour, with helium gas flow, to remove oxygen and
solvent. For helium flow, heat to 340°C for four hours, then reduce heat to 250°C, and condition with
helium flow until baseline stability.
After the conditioning procedure, equilibrate the column, injector and detector to the temperatures
and gas flow specified in the monograph until a stable baseline is obtained. Prepare sample and
reference solution(s) as described. Solutions must be free of solid particles.
Many drugs are polar reactive molecules. In that case, conversion to less polar and more volatile
derivatives may be necessary by treating the reactive groups with appropriate reagents.
Assays require quantitative comparison of one chromatogram with another. The biggest source of
error is the irreproducibility of the amount of sample injected, especially when manual injections are
performed with the aid of a syringe. Variability effects can be minimized by adding an internal
standard, a non-interfering substance added at the same concentration in the sample and standard
solutions. The ratio of the analyte peak response to the internal standard peak response is compared
between the sample and standard chromatograms. When the internal standard is chemically similar
to the substance being analyzed, there is also a compensation for minor variations in column and
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.17-00
detector characteristics. In some cases, the internal standard can be used during sample preparation,
prior to chromatographic analysis, to control other quantitative aspects of the assay. Automatic
injectors increase the reproducibility of sample injections and reduce the need to use internal
standards.
APPARATUS
The apparatus consists of a gas chromatograph to which a device for introducing the sample is fitted,
which can be connected to a programming module that automatically controls pressure and
temperature. If necessary, a solvent removal device can be fitted. The sample to be analyzed is
introduced into a flask equipped with a suitable shutter, which closes it, and with a valve system,
which allows the entry of a carrier gas. The vial is placed in a thermostatic chamber at a certain
temperature for the sample to be examined. The sample is left at this temperature long enough to
allow for the balance between the solid phase and the gas phase. The carrier gas is introduced into the
flask and, after a certain time, a valve is opened to allow the gas to expand into the chromatographic
column, dragging out the volatile components.
Instead of using a specially adapted chromatograph for introducing samples, hermetic syringes and a
conventional chromatograph can also be used. In this case, the equilibrium between the two phases
is conducted in a separate chamber and the vapor phase is transferred to the column, taking the
necessary precautions to avoid any modification of the equilibrium.
PROCEDURE
Adjust the apparatus working conditions in order to obtain a satisfactory response, using the reference
solutions.
Direct calibration
Introduce, separately, in identical vials, the preparation to be examined and each of the reference
solutions, according to the conditions described in the monograph and avoiding contact between the
sample and the injection device. Hermetically close the flasks and place them in the thermostatic
chamber at the temperature and pressure described in the monograph. After reaching equilibrium,
proceed with the chromatographic analysis under the conditions described.
Standard addition
Add equal volumes of the solution to be examined to a series of identical vials. Add to all but one of
the vials increasing amounts of a reference solution of known concentration of the substance to be
examined. A series of preparations containing increasing amounts of a certain substance is then
obtained. Hermetically close the vials and place them in the thermostatic chamber at the temperature
and pressure described in the monograph. After reaching equilibrium, proceed with the
chromatographic analysis under the conditions described.
Calculate the formula of the straight line by linear regression, using the method of least squares and,
from it, obtain the concentration of the substance under examination in the sample preparation,
indicated by the formula intercept.
5.2.18 POLAROGRAPHY
Polarography, an electrochemical analytical method, is based on measuring the electrical current
resulting from the electrolysis of electroactive substances (reducible or oxidizable) under certain
electrode potential and controlled conditions. In other words, the method involves recording the
increase in the current in a polarizable electrode, during the electrolysis of a substance dissolved in
the electrolytic medium, due to the increase in voltage applied to the system. The graph of this current
evolution in relation to voltage – the polarogram – provides qualitative and quantitative information
about electro-reducible or electro-oxidizable constituents of the sample.
Among the variants of the polarographic method, the simplest is the direct current method. It requires,
like potentiometry, the use of two electrodes, the reference (usually saturated calomel electrode, SCE)
and the indicator microelectrode (usually dropping mercury electrode, DME). In some cases, a third
auxiliary electrode is used. The SCE – with a high surface area – provides constant potential during
the test, while the DME – drops of mercury of reproducible dimensions flowing periodically from the
end of a capillary connected to the metal reservoir – assumes the potential supplied to it by the external
source. The polarographic apparatus comprises, in addition to the electrodes, the polarographic cell
(electrolysis tank), variable power supply, equipped with a voltmeter and microammeter
(galvanometer) and a graphic or digital recorder.
In simple terms, the method consists of dissolving the sample (the method is sensitive to
concentrations of electroactive species in the range of 10-2 to 10-4 M) in a supporting electrolyte,
responsible for maintaining a small residual current, but which is inert in the sample transformation
potential range (electrochemical potential window). Initially, without applying voltage to the source
(precision potentiostat), the voltage supplied to the microelectrode is null and there will be no
indication of current in the microammeter. The increasing voltage rise will cause small potential to
reach the electrodes. Under this voltage, which is still reduced, eventual impurities of the supporting
electrolyte and small oxygen concentrations may suffer a reduction in the DME (cathode, in this
case), reducing and causing the indication of a small current passage. The progressive increase in the
applied voltage will accentuate the reduction process and the almost proportional increase in current.
Finally, the necessary potential for the reduction of the analyte in the sample solution is reached,
which is reflected in a sharp rise in the current read in the microammeter (galvanometer) and recorded
in the polarogram. There is, however, a limit to the proportionality of the voltage-current rise. As the
current rises (and the reduction proceeds), there is a progressive decrease in the concentration of the
original electroactive species near the electrode surface. At a given moment - the speed of electrolysis
being constant - such concentration reaches an insufficient level to allow additional current elevation
and the latter becomes limited by the diffusion with which the electroactive species manages to
diffuse into the interior of the electrolyte solution to the surface of the DME. The plateau observed in
the polarogram appears (Figure 1), with the measured current – then called diffusion current – being
a parameter proportional to the concentration of electroactive species in the sample (quantitative
aspect of the polarography). Once a certain voltage level is exceeded, the current rises again. This
increase is caused by the reaction of the supporting electrolyte. Its presence, in high concentrations,
prevents the electroactive molecules in the sample from reaching the microelectrode by electrical
migration and, therefore, ensures that the limit current is effectively regulated only by diffusion.
When using a dropping mercury microelectrode, the surface of the electrode is constantly renewed (a
new drop is formed every three to five seconds), then there is a variation in the measured current
within a given range; the current is lower when the drop forms, reaching its maximum at the moment
of the drop. The phenomenon explains the “sawtooth” shape characteristic of the polarographic wave.
POLAROGRAM
id = i l + ir
Two other undesirable currents – migration and convection – can incorporate the limiting current.
The first is suppressed by the use of an inert support electrolyte in the potential range used, in
concentrations at least 100 times greater than those of the electroactive species. The convection
current, in turn, is eliminated by not shaking the solution.
Finally, the D segment of the polarogram, in which there is a reversal of the voltage-current
proportionality, corresponds to the reduction of other electroactive species, when present, or, more
frequently, to the electrolysis of the support.
llkovic equation
Ilkovic equation establishes relations between variables included in the polarographic measurement
and the DME diffusion current:
1 2 1
𝑖𝑑 = 708𝑛𝐷 𝐶𝑚 𝑡
2 3 6
where
𝑖𝑑 = diffusion current, in µA;
708 = constant dependent on several parameters, including the unit adopted for the variables,
dimension of the mercury drop and the instant measurement of 𝑖𝑑 ;
n = number of electrons necessary for the reduction or oxidation of an electroactive substance
molecule or ion;
D = diffusion coefficient, in cm 2/s;
C = concentration of electroactive substance, in millimoles/L;
m = mass of mercury flow, in mg/s;
t = drop lifetime, in s.
The constant 708 – encompassing the natural constant and the faraday value – is established for
operation at 25 °C and is applicable to sampled direct current polarography, in which, instead of the
continuous current record, only the current is read at the end of the life of the mercury drop, allowing
to obtain a linear polarogram. However, when using instruments equipped with a “sawtooth” damper
on the recorder, the average current of the pulses is considered. The diffusion current obtained
according to the Ilkovic equation becomes the average for the entire life of the mercury drop. In this
case the constant acquires the value 607.
The variables included in the Ilkovic equation must be controlled so that the diffusion current is
effectively proportional to the concentration of electroactive species in the analyzed sample. Some
ions and organic molecules in aqueous solution modify their diffusion coefficient at a rate of 1% to
2% for each degree Celsius increased, making it necessary for the polarographic cell to have its
temperature controlled with a tolerance of ± 0.5 ºC. The parameters m and t, related to the dimension
and speed of renewal of the mercury drop, depend on the capillary geometry, the diffusion current
being proportional to the square root of the height of the mercury column. Appropriate heights,
measuring from the end of the capillary to the level of mercury in the reservoir – are between 40 cm
and 80 cm. The internal diameter of the capillary in this case is 0.04 mm for lengths between 6 cm
and 15 cm. The exact height of the capillary is adjusted to allow a drop to be formed every three to
five seconds, with an open circuit and the capillary immersed in the electrolyte under test. Thus, if
during a particular test, all parameters – with the exception of the concentration of the electroactive
species – are kept constant, the Ilkovic equation can be written as
𝑖𝑑 = 𝐾𝐶
This direct relation between diffusion current and concentration is usually adopted by previously
determining the diffusion current of a reference standard solution of known concentration. Then,
under identical conditions, the diffusion current of the sample is determined and, finally, its
concentration:
(𝑖𝑑 )𝑃 𝐶𝑃
=
(𝑖𝑑 )𝐴 𝐶𝐴
Since most polarographs are equipped with automatic recorders, it is easier to graphically determine
diffusion currents by measuring the height of the polarographic wave (see Figure 1). The values
recorded, in cm, can be directly applied to the formula, without the need to convert them into units of
electrical current:
𝐴𝑃 𝐶𝑃
=
𝐴𝐴 𝐶𝐴
where AP and AA correspond to the heights of the polarographic waves of the standard and the sample,
respectively.
Half-wave potential
Measurement of the height of the polarographic wave for the purposes of quantitative analysis must
be carried out by plotting straight lines close to the peaks of the oscillations of the residual current
and the limit current and joining, by means of a third straight line parallel to the axis of the abscissa,
the extensions of the first two. The vertical line is plotted passing through the inflection point of the
polarographic wave, corresponding to half the distance between the residual current and the limit
current (I = l / 2id). The projection of this line onto the ordinate axis provides the so-called half-wave
potential, a parameter used to characterize electroactive substances (qualitative aspect of
polarography). The half-wave potential, E1/2, is given in volts versus SCE (reference electrode), unless
otherwise specified, and its value as an identification parameter derives from its independence from
concentration and DME characteristics. However, this parameter varies depending on the
composition, pH and temperature of the electrolytic medium. It is noteworthy that for modern
equipment the measurement of the height of the polarographic wave can be done automatically using
specific programs for data acquisition and processing.
Oxygen removal
Oxygen is reduced in DME in two steps, first converting to hydrogen peroxide and then to water. The
fact that such reactions occur at potentials more negative than zero volts, versus SCE, and may thus
interfere with the polarographic wave of the sample, requires the elimination of the gas dissolved in
the solution prior to determination. The best method is to bubble oxygen-free nitrogen through the
solution for a period of 10 to 15 minutes immediately before the test, taking the precaution of
previously saturating the nitrogen (to avoid changes in the electrolyte solution due to evaporation) by
bubbling through small volume of electrolyte solution in a separate container.
It is important to keep the electrolytic tank still and vibration-free during the polarographic recording
in order to avoid the formation of convection currents. As a result, it is necessary to remove the
nitrogen tube from the solution during recording, and place the tube on the surface of the solution to
fill the upper part of the polarographic cell with nitrogen(N2(g)) thus preventing the entry of air in the
polarographic cell. Alkaline solutions can be deoxygenated by the addition of sodium bisulfite, as
long as it does not interact with constituents of the electrolyte solution.
Polarographic maxima
After the reduction of the electroactive species (cathodized DME), the polarographic wave often rises
sharply, often before falling, equally sharply, to the value of the limit current. The phenomenon is
called polarographic maxima and the corresponding current is called adsorption current (ia). It has
the inconvenience of making it difficult to measure the polarographic wave (diffusion current) and
its causes – still poorly understood – comprise the adsorption of electrolyte to the surface of the
mercury drop. The elimination of the polarographic maxima is, however, easily accomplished by
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.18-00
adding diminutive amounts of certain surfactants (maxima suppressors) to the electrolytic medium.
For this purpose, the use of gelatin solution at 0.005% (w/v) and methyl red solution at 0.01% (w/v),
among others, stand out.
Warning
Mercury vapors are toxic. When handling metal, work in a ventilated area and avoid spills which, if
they occur, must be immediately and carefully collected.
PULSE POLAROGRAPHY
Pulse polarography is a variant of the method, superior, due to its precision and sensitivity, to direct
current polarography in the assay and identification of a large number of substances at low
concentrations, including trace level elements, metabolites and, of course, drugs. Its sensitivity, about
10 times higher than that of DC polarography, allows for determinations in the order of 10-6 M.
Time
Current measurement
Potential for applied
Current measurement
Potential for applied
drop drop
Figure 2 – Measure of current over time in direct current polarography (A); in pulse polarography (B); and
in differential pulse polarography (C)
Instead of the linearly progressive application of potential and direct measure of the developed
current, pulse polarography comprises the application of increasing potential pulses to the DME,
coinciding with the final period of life of the mercury drops, each pulse presenting a potential slightly
higher than the previous one. The current, in turn, is sampled at the final instant of the duration of
the potential pulse, a period in which the capacitive current reaches practically zero and the residual
current is composed almost exclusively of the diffusion current.
On the other hand, the pulse method does not cause an accelerated reduction in the diffusion layer
(concentration of electroactive species close to the electrode), allowing higher diffusion currents for
equivalent concentrations. Hence the increased sensitivity inherent in the method. Another favorable
aspect of pulse polarography is that it is easier to measure the limit current, free from oscillations,
unlike what occurs in direct current polarography.
5.2.19 DETERMINATION OF pH
POTENTIOMETRIC DETERMINATION OF pH
The pH value is defined as the measure of the hydrogen ion activity of a solution. The scale of the
hydrogen ion concentration of the solution is conventionally used. Water is an extremely weak
electrolyte, whose self-ionization produces hydronium ion (hydrated hydrogen) and hydroxide ion:
Hydronium ion concentrations in aqueous solutions can vary within wide limits, which
experimentally range from 1 to 10-14 M, which is defined by the simplified relation:
Thus, the pH scale is an inverted scale in relation to the hydronium ion concentrations, that is, the
lower the hydronium ion concentration, the higher the pH value.
The potentiometric determination of pH is made by measuring the potential difference between two
suitable electrodes immersed in the solution under examination. One of these electrodes is sensitive
to hydrogen ions and the other is the constant potential reference electrode.
pH = pHt = (E –Et)/ K,
where
E = potential measured when the cell contains the sample solution;
Et = potential measured when the cell contains the buffer solution;
pH = pH value in the sample solution;
pHt = pH value in the buffer solution;
K = change in potential per unit of change in pH – theoretically equivalent to 0.0591631 + 0.000198
(t–25), where t corresponds to the temperature at which it operates.
The pH value is expressed by the formula in relation to the pH of the standard solution (pH p) and
determined in a pH meter using a glass electrode.
The devices commercially used for the determination of pH are potentiometric instruments, equipped
with electronic current amplifiers with a glass-calomel cell, which are capable of reproducing values
corresponding to 0.02 pH units. The pH scale is calibrated not only in millivolts, but also in
corresponding pH units. Thus, there is no need to apply the formula above, which translates the
electrometric pH measurement. As measurements of hydrogen ionic activity are sensitive to
temperature variations, all pH meters are equipped with electronic temperature adjustment.
They are used for measuring the device, allowing linearity in the responses in relation to the observed
potential changes. The most important are: 0.05 M potassium tetraoxalate, 0.05 M equimolar
phosphate, 0.01 M sodium tetraborate, sodium carbonate and saturated calcium hydroxide at 25°C.
Potassium tetraoxalate, 0.05 M – Reduce potassium tetraoxalate to fine powder and desiccate in a
silica desiccator. Dissolve exactly 12.71g of KH3(C2O4)∙2H2O in water. Adjust volume to 1000 mL
with water and homogenize.
Potassium Biphthalate, 0.05M – Reduce potassium biphthalate to fine powder and dry at 110°C to
constant weight. Dissolve exactly 10.21g of KHC8H4O4,previously desiccated at 100°C for one hour,
in water. Adjust volume to 1000 mL with water and homogenize.
Equimolar Phosphate, 0.05M – Reduce the Na2HPO4 and KH2PO4 to fine powder and dry at 110°C
to constant weight. Dissolve 3.55g of Na2HPO4 and 3,40g of KH2PO4 in water. Adjust volume to
1000 mL with water and homogenize.
Sodium tetraborate, 0.01M – Desiccate the sodium tetraborate in a desiccator containing an aqueous
solution of sodium bromide to constant weight. Dissolve 3.81g of Na2B4O7∙10H2O, in water Adjust
volume to 1000 mL with water and homogenize. Avoid carbon dioxide absorption.
Calcium hydroxide, saturated at 25°C – Reduce calcium hydroxide to fine powder and desiccate
with silica in desiccator to constant weight. Transfer 5 g to volumetric flask and add water up to
1000 mL. Shake well and keep at a temperature of (25 ± 2) ºC, for adequate saturation (approximately
0.02 M). Decant at 25°C before use. Protect to avoid carbon dioxide absorption.
Sodium carbonate – Desiccate the sodium carbonate in a desiccator with silica gel until constant
weight. Weigh exactly 2.10 g. Dry the flask in an oven at 300°C to 500 °C until constant weight.
Weigh 2.65g. Dissolve both samples in water. Transfer each solution to a 1000 mL volumetric flask,
adjust volume with water and homogenize.
Such solutions must be freshly prepared with carbon dioxide-free water and used within three months,
taking care to avoid the growth of fungi and bacteria. Preservatives are accepted as long as they do
not interfere with the potentiometric PH measurement.
The water used to prepare the solutions must be freshly distilled, heated to boiling for at least 15
minutes, cooled and kept in a container impermeable to carbon dioxide. Prepare the six standard
solutions individually and store them in suitable glass or polyethylene flasks. Observe the shelf life
of the solutions, as the pH changes over time.
Table 1 – Relation between temperatures and pH values of buffer solutions for pH meter calibration.
Saturated
Potassium Potassium Sodium
Temperature Equimolar calcium Sodium
tetraoxalate Biphthalate tetraborate
(ºC) phosphate hydroxide at carbonate
0.05M 0.05M 0,01M
25°C
10 1.67 4.00 6.92 9.33 13.00 10.18
15 1.67 4.00 6.90 9.27 12.81 10.12
20 1.68 4.00 6.88 9.22 12.63 10.07
25 1.68 4.01 6.86 9.18 12.45 10.02
30 1.68 4.01 6.85 9.14 12.30 9.97
35 1.69 4.02 6.84 9.10 12.14 9.93
40 1.70 4.03 6.84 9.07 11.99 -
PROCEDURE
pH meter gauge
Remove the beaker containing KCl solution in which the electrode is immersed when the meter is not
in use;
Wash the electrode with jets of distilled water and dry with filter paper;
Immerse the electrode in a reference buffer solution, checking the temperature at which it will operate;
Adjust the pH value to the tabulated value using the calibration value;
Wash the electrode with several portions of the second reference buffer solution, immerse the
electrode and check the pH value recorded. The pH value must not vary by more than 0.07 from the
tabulated value for the second standard solution. There are devices that have flasks coupled with
anionic detergents, used as washing solutions between each of the pH measurement operations. Water
also lends itself to this function;
If the measurements are not accurate, check for possible damage to the electrodes and replace them.
After the convenient measurement, wash the electrode with water (or proper solutions) and with
several portions of the sample solution. For sample dilution, use carbon dioxide-free distilled water;
The first determination provides a variable value, requiring further readings. The values found later
should not vary by more than 0.05 pH unit on three serial readings;
For determinations that require high precision, the temperatures of the buffer and sample solutions,
of the electrodes and of the washing waters must not differ by more than 2°C from each other. Thus,
to reduce the effects of thermal or electrical hysteresis on the electrodes, the solutions must be at the
same temperature for minimum 30 minutes before starting the operation;
It is important that, after using the device, the electrode is kept in an appropriate solution, usually
KCl.
Contamination of stock solutions must be avoided by adopting systematic procedures, such as the
immediate closing of the vials containing the solutions, in order to prevent accidental introduction of
pipettes or sticks, and the use of individual pipettes for each solution.
COLORIMETRIC DETERMINATION OF pH
It is based on the use of test solutions or indicator papers, which have the property of changing color
as the pH changes. In this case, it is an approximate measure, indicating only a range of values, more
or less wide, depending on the indicator used. The determination is carried out by adding drops of the
indicator solution to the solution under examination or by moistening indicator papers with the
solution under examination and observing the change in color. The colors produced by indicators in
various pH ranges are listed in Indicators and test solutions (7.1)
A solution is considered neutral when it does not change the color of the litmus blue and red papers,
or when the universal indicator paper takes on the colors of the neutral scale, or when 1 mL of the
same solution is colored green with a drop of bromothymol blue TS (pH 7.0).
It is considered acidic when the blue litmus paper is stained red or 1 mL is stained yellow by a drop
of phenol red TS (pH 1.0 to 6.6).
It is considered weakly acidic when the blue litmus paper is slightly stained red or 1 mL is stained
orange by a drop of methyl red TS (pH 4.0 to 6.6).
It is considered strongly acidic when the Congo red paper is stained blue or 1 mL is stained red by
the addition of a drop of methyl orange TS (pH 1.0 to 4.0).
It is considered alkaline when the red litmus paper is stained blue or 1 mL is stained blue by a drop
of bromothymol blue TS (pH 7.6 to 13.0).
It is considered weakly alkaline when the red litmus paper is stained blue or 1 mL is stained pink by
a drop of cresol red TS (pH 7.6 to 8.8).
It is considered strongly alkaline when stained blue by a drop of thymolphthalein TS (pH 9.3 to 10.5)
or red by a drop of phenolphthalein TS (pH 10.0 to 13.0).
Many substances are in the form of hydrate or contain adsorbed water, so it is important to determine
them by specific methods.
Depending on the nature of the substance, the individual monograph will specify one of the methods
described below.
In the original volumetric solution, known as Karl Fischer Reagent, sulfur dioxide and iodine are
usually dissolved in pyridine and methyl alcohol, and other solvents and/or bases may be used, thus
requiring checking the stoichiometry and the absence of interferences. For this purpose, commercial
reagents can be used, considering the manufacturer’s recommendations.
There are two different methods based on the reaction with iodine: volumetric titration and
coulometric titration.
In the first method, iodine is dissolved in the reagent and the water content is determined by measuring
the amount of iodine consumed as a result of the reaction with water. The test sample can be titrated
directly with the reagent or the analysis can be performed using an indirect titration procedure. The
reaction stoichiometry is not accurate and the reproducibility of the determination depends on factors
such as the relative concentrations of the reagent components, the nature of the inert solvent used to
dissolve the test sample, and the method used in the determination. Therefore, it is necessary to
standardize the method beforehand to achieve adequate accuracy. The accuracy of the method
depends on the effectiveness of removing atmospheric moisture from the system.
In coulometric titration, iodine is produced by the electrolysis of a Karl Fischer reagent that contains
the iodide ion. The water content in a sample can be determined by measuring the amount of
electricity required to produce iodine during titration.
2I- → I2 + 2e-
Apparatus
Knowing that Karl Fischer reagent is highly hygroscopic, the apparatus must ensure an exclusion of
atmospheric moisture. The endpoint determination must be adequate. In the direct titration of a
colorless solution, the endpoint can be visually observed with a color change from deep yellow to
amber. The inverse is observed when carrying out a backtitration (indirect) of a test sample. However,
more commonly, the endpoint is determined by a voltametric method using an apparatus with a simple
electrical circuit that generates an applied potential of approximately 200 mV between a pair of
platinum electrodes submerged in the solution containing the sample that will be titrated. At the end
of the assay, a slight excess of the reagent increases the current flow between 50 µA and 150 µA for
a period of 30 seconds to 30 minutes, depending on the solution being titrated. This period is shorter
for substances that dissolve in the reagent. In some automatic volumetric titrators, the abrupt change
in current or potential at the endpoint causes a valve to be closed by a solenoid that controls the burette
that delivers the volumetric solution. Commercially available apparatus generally comprise a closed
system, consisting of one or two automatic burettes and a hermetically closed titration vessel,
equipped with the required electrodes and a magnetic stirrer. The air in the system is kept dry with a
suitable desiccant, e.g. anhydrous calcium chloride or silica gel, and the titration flask can be purged
by means of a stream of dry nitrogen or dry air.
Reagent
Karl Fisher reagent can be prepared by any of the methods listed below.
Note: Chloroform and methyl alcohol used for reagent preparation must have a water content
inferior to 0.1 mg/mL. Methoxyethanol and diethylene glycol monomethyl ether must have a water
content lower than 0.3 mg/mL.
Method a – Add 125 g of iodine to a solution containing 670 mL of methyl alcohol and 170 mL of
pyridine, and cool. Place 100 mL of pyridine in a 250 mL graduated cylinder and, keeping the
pyridine cold in an ice bath, introduce dry sulfur dioxide until reaching a volume of 200 mL. Slowly
add this solution to the cooled iodine mixture, shaking until the iodine dissolves. Transfer the solution
to the apparatus and allow the solution stand for 24 hours before standardizing. One mL of this fresh-
prepared solution is equivalent to approximately 5 mg of water. Protect the solution from light while
in use. To determine water in trace amounts (less than 1%), it is preferable to use a reagent with a
water equivalence factor not greater than 2.0, which will generate the consumption of a more
significant volume of the volumetric solution.
Method b – Dissolve 63 g of iodine in 100 mL of pyridine, with a water content of less than 1 mg/mL,
cool the solution in an ice bath and pass dry sulfur dioxide through this solution until the weight gain
reaches 32 g. Adjust to 500 mL with chloroform or methyl alcohol and allow to stand for minimum
24 hours before using.
Method c – Dissolve 102 g of imidazole, with a water content of less than 0.1%, in 350 mL of
methoxyethanol or diethylene glycol monomethyl ether, cool the solution in an ice bath and pass dry
sulfur dioxide through this solution until the increase in weight is 64 g, keeping the temperature
between 25°C and 30°C. Dissolve 50 g of iodine in this solution and allow to stand for at least 24
hours before using.
Method d - Pass sulfur dioxide through 150 mL of methoxyethanol until the weight gain is 32 g. To
this solution, previously cooled in an ice bath, add 250 mL of methoxyethanol or chloroform
containing 81 g of 2-methylaminopyridine, with a water content lower than 1 mg per mL. Dissolve
36 g of iodine in this solution and allow to stand for at least 24 hours before using.
Karl Fischer reagent prepared by any of these methods should be standardized within one hour of use
or daily if used continuously, as its activity for water determination varies with time. Store reagent
refrigerated, protected from light and moisture.
A commercially available stabilized solution of Karl Fisher reagent can be used. Commercially
available reagents which contain solvents or bases other than pyridine or alcohols rather than methyl
alcohol can also be used. These can be individual solutions or reactants formed in situ by combining
the components of the reactants present in two different solutions. The diluted reagent required in
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.20-00
some monographs should be diluted according to manufacturer’s instructions. Methyl alcohol or other
suitable solvent such as diethylene glycol monomethyl ether can be used as diluent,
Reagent Standardization
Place a sufficient amount of methyl alcohol or other suitable solvent in the titration flask to cover the
electrodes and add sufficient amount of Reagent until the endpoint characteristic color is obtained, or
(100 ± 50) µA of direct current with an applied potential of approximately 200 mV.
F = P/V
where
P = weight, in mg, of the water contained in the aliquot of the standard used;
V = volume, in mL, of the Reagent used in the assay.
For sodium tartrate dihydrate (C4H4Na2O6.2H2O), quickly add between 20 mg and 125 mg accurately
weighed, and titrate to endpoint. The water equivalence factor, F, in mg of water per mL of reagent,
is calculated by the formula:
F = (36.04/230.08) P/V
where
36.04 = twice the molar mass of water;
230.08 = molar mass of sodium tartrate dihydrate;
P = weight, in mg, of sodium tartrate dihydrate;
V = volume, in mL, of the Reagent used in the assay.
Note: the solubility of sodium tartrate dihydrate in methyl alcohol is such that the use of additional
methyl alcohol may be required for further standard assays.
Sample preparation
If not otherwise specified in the individual monograph, use a weighed or accurately measured amount
of the sample under analysis with an estimated water content between 2mg and 250mg. The amount
of water depends on the water equivalence factor of the Reagent and the endpoint determination
method. In most cases, the minimum sample quantity (Pm), in mg, can be estimated using the formula:
Pm = FCV/Kf
where
F = Reagent water equivalence factor, in mg/mL;
C = volume used, in percentage of burette capacity;
V = volume of the burette, in mL;
Kf = limit or expected content of water in the sample, in percentage.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.20-00
C is generally between 30% and 100% for manual assay and between 10% and 100% for the
instrumental method for determination of endpoint.
Note: FCV product must be greater than or equal to 200 for the calculation, to ensure that the
minimum amount titrated is greater than or equal to 2 mg.
If the sample being analyzed is an aerosol with propellant, store in freezer for not less than two hours,
open the container and analyze 10.0 mL of the sample thoroughly mixed. To titrate the sample,
determine the endpoint at a temperature of 10°C or higher.
For the analysis of capsules, use a portion of the homogenized content of at least four units. If
necessary, pulverize the contents into fine powder.
If the sample under analysis is for tablets, use the powder of at least four tablets pulverized to fine
powder in an atmosphere with temperature and relative humidity values that do not affect the results.
In cases where the monograph specifies that the sample under analysis is hygroscopic, place a portion
of the solid, accurately weighed, in a titration cup, proceeding with the determination of water
immediately, to avoid absorption of atmospheric moisture.
If the sample consists of a defined amount of solid, such as a lyophilized product or powder in a flask,
use a dry syringe to inject an appropriate volume of methyl alcohol or other appropriate solvent,
accurately measured, into a tared container and shake until the sample dissolves. With the same
syringe, remove the solution from the container, transfer to a titration flask prepared as described in
Procedure and titrate immediately. Determine the consumption of reagent used in the titration of the
solvent volume used to prepare the sample and subtract this value from that obtained in the titration
of the sample under analysis. Dry the container and lid at 100°C for three hours, allow to cool in a
desiccator and weigh. Determine the weight of the analyzed sample from the difference in weight in
relation to the initial weight of the container.
When appropriate, water can be desorbed or released from the sample by heat in an external oven
connected to the beaker, to which it is transferred with the aid of a dry inert gas such as pure nitrogen.
Take care and correct any deviation due to carrier gas. Carefully select heating conditions to avoid
water formation as a result of dehydration due to decomposition of sample components, which may
invalidate the method.
Procedure
If not otherwise specified in the individual monograph, transfer a sufficient amount of methyl alcohol
to the titration cup, ensuring that the volume is sufficient to cover the electrodes (approximately 30
to 40 mL), and titrate with the reagent up to the electrometric or visual endpoint to consume any
moisture that may be present (do not consider the volume consumed in the calculation). Quickly add
prepared sample as instructed in Sample Preparation, mix and titrate with Reagent up to electrometric
or visual endpoint. Calculate the water content of the sample, in percentage, using the formula:
(𝑉𝐹 × 100)
% á𝑔𝑢𝑎 =
𝑚
where
V = volume, in mL, of the Reagent used in the titration;
F = Reagent water equivalence factor
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.20-00
In this titration, an excess of Reagent is added to the sample, a sufficient time is allowed for the
reaction to complete and the unused Reagent is titrated with a standard solution of water in a solvent
such as methyl alcohol. The backtitration procedure is generally applied and avoids the problems that
can arise in direct titration of substances in which the bonded water is slowly released.
Prepare a water solution by diluting 2 mL of water with methyl alcohol or other suitable solvent to
1000 mL. Standardize this solution by titrating 25.0 mL with the Reagent, previously standardized as
described in Standardization of the reagent. Calculate the water content (Cwater), in mg per mL, of the
Water Solution, using the formula:
𝐶á𝑔𝑢𝑎 = 𝑉𝐹/25
where
V = volume of the Reagent consumed, in mL;
F = Reagent water equivalence factor, in mg/mL;
Procedure
Transfer a quantity of methyl alcohol or other suitable solvent to the titration cup, ensuring that the
volume is sufficient to cover the electrodes (approximately 30 mL to 40 mL) and titrate with the
Reagent to the electrometric or visual endpoint. Quickly add the sample, homogenize and add an
accurately weighed excess of Reagent. Wait a sufficient time for the reaction to complete and titrate
the unused Reagent with the Standard Water Solution to the electrometric or visual endpoint.
Calculate water content (%water) of the sample using the formula:
𝐹 (𝑋 ′ − 𝑋𝑅)100
% á𝑔𝑢𝑎 =
𝑚
where
COULOMETRIC METHOD
For the coulometric determination of water, the Karl Fischer reaction is used. Iodine, however, is not
added in the form of a volumetric solution, but is obtained by anodic oxidation in a solution containing
iodide. The reaction cell usually consists of a large anode compartment and a small cathode
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.20-00
compartment, separated from each other by a diaphragm. Other suitable types of reaction cells (e.g.
without diaphragm) can also be used. Each compartment has a platinum electrode that conducts
current through the cell. Iodine, which is produced at the anode electrode, immediately reacts with
the water in the compartment. When all the water is consumed, an excess of iodine is produced which
is normally detected electrometrically, which indicates the endpoint. Moisture is removed from the
system through pre-electrolysis. It is not necessary to change the solution in the cup after each
determination. A requirement of this method is that each component of the sample is compatible with
the other components and that no secondary reactions are produced. Samples are normally transferred
to the cup as a solution by injection through a septum. Gases can be introduced into the cell using a
suitable gas inlet tube. The accuracy of the method fundamentally depends on the degree of
elimination of atmospheric moisture in the system; therefore, the introduction of solids into the cell
may require precautions such as working in a dry inert gas atmosphere. System control can be
performed by measuring the baseline derivative, which does not exclude the need for a blank
correction when using sample introduction vehicle. This method is especially suitable for inert
chemical substances such as hydrocarbons, alcohols and ethers. Compared to Karl Fischer volumetric
assay, coulometric is a micromethod.
When appropriate, water can be desorbed or released from the sample by heat in an external oven
connected to the beaker, to which it is transferred with the aid of a dry inert gas such as pure nitrogen.
Take care and correct any deviation due to carrier gas. Carefully select heating conditions to avoid
water formation as a result of dehydration due to decomposition of sample components, which may
invalidate the method.
Apparatus
The use of any commercially available device that has an absolutely hermetic system, equipped with
the necessary electrodes and a magnetic stirrer, is allowed. The equipment microprocessor controls
the analytical procedure and displays the results.
Reagent
Electrolyte solutions can be prepared by any of the following procedures, and commercial reagents
can also be used.
Note: Chloroform and methyl alcohol used for reagent preparation must have a water content
inferior to 0.1 mg/mL. Methoxyethanol and diethylene glycol monomethyl ether must have a water
content lower than 0.3 mg/mL.
Method a – ANOLYTE SOLUTION: Dissolve 102 g of imidazole in 900 mL of methyl alcohol, cool
the solution in an ice bath and pass dry sulfur dioxide through the solution kept at a temperature below
30 °C, until weight is 64 g. Dissolve 12 g of iodine by agitating, add an appropriate amount of water
to the solution until the liquid turns brown to yellow, and dilute to 1000 mL with methyl alcohol.
CATHOLYTE SOLUTION: dissolve 24 g of diethanolamine hydrochloride in 100 mL of methyl
alcohol.
Sample preparation
When the sample is a soluble solid, an appropriate amount, accurately weighed, can be dissolved in
anhydrous methyl alcohol or other suitable solvents. When the sample is an insoluble solid, an
appropriate amount can be extracted, accurately weighed, using a suitable anhydrous solvent and
injected into the anolyte solution. Alternatively, an evaporation method can be used in which water
is released and evaporates by heating the sample in a tube in a stream of dry inert gas. The gas soon
passes into the cell.
When the sample is to be used directly without being dissolved in a suitable anhydrous solvent, an
appropriate amount, accurately weighed, can be introduced directly into the anode compartment.
When the sample is a liquid miscible in anhydrous methyl alcohol or other suitable solvents, an
appropriate amount, accurately weighed, may be added to the anhydrous methyl alcohol or other
suitable solvents.
Procedure
Using a dry device, inject or add directly into the anolyte an accurately measured amount of the
sample or sample preparation that contains between 0.5mg and 5mg of water, or the amount
recommended by the instrument manufacturer, mix and carry out the coulometric titration up to the
electrometric endpoint. Read the water content of the sample preparation directly from the instrument
screen and calculate the percentage present in the substance. Carry out a blank determination, if
necessary, and make the corresponding corrections.
Apparatus
Use a 500 mL round bottom glass flask, A, connecting through a connection, B, to a reflux condenser,
C, using ground glass joints (Figure 1).
The critical dimensions of the apparatus parts are as follows: the connecting tube, D, has an inner
diameter of 9 mm to 11 mm. The distillate collector has a length of 235 mm to 240 mm. The
condenser should be of the straight tube type, with an approximate length of 400 mm and an internal
diameter of not less than 8 mm. The receiving tube, E, has a capacity of 5 mL and its cylindrical part,
with a length of 146 mm to 156 mm, is graduated in 0.1 mL subdivisions, so that the reading error is
not greater than 0.05 mL for any volume indicated. The heat source is preferably a thermostatically
controlled electric heater or an oil bath. The top of the flask and the connecting tube may be insulated.
Clean the receiver tube and condenser with a suitable cleaning solution, rinse thoroughly with water
and dry. Prepare the toluene that will be used by shaking with a small amount of water, and distil
until water excess is removed.
Procedure
Place in a dry flask an amount of the substance, accurately weighed, containing from 2 mL to 4 mL
of water. If the substance is of the semi-solid type, weigh on an oval metal plate with a size that passes
through the flaks neck. If there is a possibility of projections being produced when introducing the
substance, add a quantity of porous material (for example: washed and dry sand, capillary tubes,
porcelain). Place approximately 200 mL of toluene in the flask, connect the apparatus and fill the
receiving tube, E, with toluene poured through the upper opening of the condenser. Heat the flask
gently for 15 minutes and, as soon as the toluene has boiled, distill at a rate of approximately two
drops per second until most of the water has been washed away, then increase the distillation rate to
approximately four drops per second. When all the water appears to have been distilled, rinse the
inside of the condenser tube with toluene. Continue the distillation for another five minutes; remove
the heat source and allow the receiving tube to cool to room temperature and drag the water adhering
to the walls. After completing the separation of water and toluene, read the volume of water and
calculate the percentage present in the substance.
Use iodosulfuron RS after determining its equivalent in water. The solutions and reagents used must
be stored in an anhydrous condition and protected from atmospheric moisture during the assay or
upon any handling.
Iodosulfuron RS must be stored protected from light, preferably in a flask fitted with an automatic
burette.
Commercially available iodosulfuron RS solutions have (or may have) a composition that differs
from the iodosulfuron RS solution by replacing pyridine for several basic substances. The use of these
reagent solutions must be preceded by an evaluation that allows, in each case, to verify the
stoichiometry and the absence of incompatibility between the substance to be tested and the reagent.
Unless otherwise indicated, Method A must be used.
Method A. Introduce about 20 mL of anhydrous methyl alcohol or the solvent prescribed in the
monograph into the titration flask. Add iodosulfuron R solution to the reagent flask until the
amperometric changeover. Quickly introduce the assay intake, shake for one minute and titrate with
the iodosulfuron RS solution until new changeover.
Method B. Introduce in the titration flask about 10 ml of anhydrous methyl alcohol or of the solvent
prescribed in the monograph. Add iodosulfuron RS until the amperometric changeover. Quickly
introduce the substance sample intake and then a volume of iodosulfuron RS sufficient to obtain an
excess of approximately 1 mL. In this case, as well, the volume prescribed in the monograph can be
used. Allow to stand in a closed flask and protected from light for one minute or for the time
prescribed in the monograph, shaking occasionally. Titrate the excess of iodosulfuron RS with
anhydrous methyl alcohol or with another solvent prescribed in the monograph, adding a known
quantity of water close to 2.5 g/L, until returning to the initial weak current.
Procedure for herbal drugs. Proceed as indicated in Methods of pharmacognosy (5.4), as indicated
in the individual monograph.
If the sample consists of two substances (one of them impurity of the other, for example), the diagram
takes the form shown in Figure 2. Segment AB has a unit slope; point B indicates saturation of the
solution with respect to one of the sample components (generally the one that is present in greater
proportion); the BC segment indicates the solubilization of the second component and the CD
segment the saturation of the solution with the latter (zero slope).
The slope value of the BC segment – phase in which only the second component is dissolved –
corresponds to the proportion of this component in the sample. The subtraction of this unit value
provides the content of the first component in the sample, allowing the use of the formula (1-i).100
to obtain the content. The slope, i, is obtained by the formula (Y2-Y1) / (X2-X1), where Y1, Y2 and
X1, X2 correspond, respectively, to projections of points on the line segment BC on the ordinate
(composition of the solution) and the abscissa (composition of the system). The extrapolation of the
BC segment gives the solubility limit, S1, in mg of solute per g of solvent, of the first component,
whereas the extension of the line from the segment CD to the Y axis leads to the sum of the solubilities
of the two components, S1 + S2.
The occurrence of pronounced deviations at the points that form the straight segments of the diagram
indicates a lack of equilibrium in the system, although these can also be attributed to the existence of
a solid solution or to deviations from the theoretical behavior. If necessary, the slope i can be
calculated by graphical approximation or using the least squares statistical method.
A peculiarity of the phase solubility analysis is that it is not a method applicable to mixtures whose
components are present in the sample in proportion to their solubilities. In this particular case, both
components promote saturation at the same point, providing, as a result, a phase diagram equivalent
to that of pure substance.
CHOICE OF SOLVENT
The choice of solvent for phase solubility analysis is based on the solubility of the component present
in greater proportion in the sample and on the assay method adopted to determine the concentration
of the formed solution. As the gravimetric method is more common, the solvent should present
sufficient volatility to allow evaporation in a vacuum, but insufficient to hinder transfer and weighing
operations.
Solvents with a boiling point between 60 ºC and 150 ºC are recommended. In terms of solubility, it
is convenient that the solvent has the capacity to dissolve the sample in a proportion not lower than 4
mg/g or greater than 50 mg/g. Optimum solubility is in the range of 10 to 20 mg/g. Additional
recommendations include the solvent inertia towards the sample components (including the
possibility of formation of solvates or salts) and the use of solvents of known purity and concentration
(trace of impurities strongly affect the solubility), admitting, however, the use of mixtures.
APPARATUS
Comprises thermostatized water bath, appropriate vials and ampoules and analytical balance, with
accuracy of ± 10 µg.
The water bath is provided with a thermostat with a temperature control tolerance of not more than
0.1°C, especially in the range of 25°C to 30°C, which is usual for testing. The bath is equipped with
a horizontal rotating rod (25 rpm) provided with holding clamps for the ampoules. As an alternative,
a vibrator (100 to 120 vibrations/second) can be used, also equipped with ampoule holding clamps.
The ampoule - with a capacity of 15 mL - next to the so-called solubility flask, also used in the tests,
is illustrated in Figure 3. Containers of different specification are admissible as long as they are
hermetic and suitable for the method described.
PROCEDURE
System composition
Allow the ampoules to reach room temperature and weigh them, together with their respective glass
fragments. Calculate system composition, in mg/g, for each ampoule, using the formula: 1000(M2-
M1)/(M3-M2), where M2 corresponds to mass of the ampoule containing the sample; M 1 is the mass
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.21-00
of the empty ampoule and M3 is the mass of the ampoule containing sample, solvent and any glass
fragments.
Equilibrium
The period necessary to establish equilibrium in the systems contained in the ampoules varies
according to nature of sample, method of agitation (rotation or vibration) and temperature. Experience
indicates an average period of 1 to 7 days for shaking by vibration and 7 to 14 days for the rotational
process. To confirm equilibrium promotion, heat the penultimate ampoule in the series to 40 ºC to
obtain supersaturation. Result is positive if the point corresponding to this ampoule is consistent with
the others in the phase diagram. However, a different result does not necessarily mean that
equilibrium has not been reached. There are substances that tend to remain in a supersaturated solution
and, if this is the case, a series of analyses, varying the waiting period, is required to ensure the
consistency of the points on the solubility curve.
Solution composition
Once equilibrium is reached, place the ampoules on an appropriate support so that they remain in a
vertical position, with the necks above water level in thermostatic bath. Wait for solids to decant in
the ampoules, open them and collect 2.0 mL of the supernatant from each ampoule using a pipette
fitted with a cotton swab or other material capable of acting as a filter. Remove filtering material from
the pipette and transfer the clear liquid to a solubility flask (Figure 3) tared and properly identified,
weighing each flask after operation. Cool vials in dry ice and acetone bath, then evaporate the solvent
under reduced pressure. Gradually increase evaporation temperature, taking care not to exceed the
limit compatible with sample stability and dry residue to constant weight. Calculate solution
composition in each vial, in mg/g, using the formula 1000 (P3 -P1)/(P2 -P3), where P3 corresponds to
the mass of the vial containing the evaporation residue; P1 is the mass of the empty solubility vial
(tare) and P2 is the mass of the vial containing the solution.
Plot a phase diagram based on the values obtained and determine sample percentage purity as a
function of the straight line slope.
While solutions obtained in the analytical process described contain essentially all the impurities
present in the sample in enhanced proportion compared to the original sample, leading – after solvent
evaporation – to the qualitative determination of impurities, the phase is suitable, due to its high
purity, for preparation of reference standards to other analytical tests.
Procedure
Weigh appropriate amount of sample and suspend it in suitable solvent so that – reached equilibrium–
only dissolve 10% of the material. Close the flask and wait for equilibrium to be established at room
temperature (usually 24 hours is sufficient). Then collect the clear supernatant solution and evaporate,
at or near room temperature, to dryness. Since the solution contains impurities from the original
sample, material in which the proportion of impurities is enhanced is obtained by this procedure, with
the enrichment ratio being approximately equal to the ratio of sample mass by the mass of dissolved
solids in the volume of solvent used. Purify undissolved residue by washing and drying (reference
standard).
5.2.22 ELECTROPHORESIS
GENERAL PRINCIPLES
By the action of an electric field, charged particles dissolved or dispersed in an electrolyte solution
migrate towards the opposite polarity electrode. In gel electrophoresis, the displacement of particles
is slowed down by interactions with the matrix gel that constitutes the migration medium and behaves
like a molecular sieve.
Opposing interactions of electrical force and molecular sieving result in the rate of migration
differential according to particle size, shape, and charge. Due to their different physicochemical
properties, the different molecules contained in a mixture will migrate at different speeds during
electrophoresis, thus being separated into well-defined fractions. Electrophoretic separations can be
conducted in systems without a support phase (e.g. free solution separation in capillary
electrophoresis), and or in stabilized media such as thin-layer plates, films or gels.
This method is mainly used in the determination of mobilities, with experimental characteristics being
directly measurable and reproducible. It applies, above all, to substances of relatively high molar
mass, not very diffusible. Divisions are initially demarcated by a physical process such as
refractometry or conductimetry. After the application of a defined electric field, for a determined
time, new divisions are obtained and their respective positions are observed. Operating conditions
allow for the determination of divisions and constituents.
This method is only used for reduced samples. The nature of the support, such as paper, agarose gel,
cellulose acetate, starch, methacrylamide or mixed gel, introduces a number of additional factors that
modify mobility:
a) due to the twisting of the support channeling, the distance apparently covered is shorter than the
actual distance;
b) certain supports are not electrically neutral and, as the medium constitutes a stationary phase, it
can sometimes give rise to considerable electroosmotic current;
c) heating due to the Joule effect can produce a certain evaporation of the liquid from the support,
which leads, by capillarity, to a displacement of the solution from the extremities to the center; thus,
the ionic strength tends to increase progressively.
The migration speed depends on four main factors: particle mobility, electroosmotic current,
evaporation current and field intensity. For these reasons, it is necessary to proceed under well-
defined experimental conditions and to use, if possible, reference standards.
Apparatus
– an electrophoresis tank. Usually rectangular, made of glass or rigid plastic material, with two
separate compartments, anodic and cathodic, which contain the conductive buffer solution. An
electrode, made of platinum or graphite, is immersed in each compartment; these are connected by a
circuit duly isolated from the power supply of the corresponding terminal to form, respectively, the
anode and cathode, connected by a circuit suitably isolated to the corresponding terminal of the
generator. The liquid level in both compartments is equal to avoid siphoning effect. The
electrophoresis tank must be equipped with a hermetic lid, allowing an atmosphere saturated with
moisture to be kept inside and thus attenuating solvent evaporation during migration. A safety device
is used that cuts the current when the lid is removed from the tank. If the measurement of electric
current exceeds 10 W, it is preferable to cool the support;
– a support device:
Strip electrophoresis. In electrophoresis, the strips on the support are pre-impregnated with the same
conductive solution and each end immersed in the electrode compartment. The strips are well
extended, fixed on an appropriate support to prevent diffusion of the conductive solution, such as a
horizontal frame, an inverted V support, or a uniform surface with contact points at suitable ranges.
Gel electrophoresis. In gel electrophoresis, the device consists of a glass plate, such as a simple
microscope slide, on which an adherent gel layer of uniform thickness is deposited on the entire
surface of the slide. The contact between the gel and the conductive solution varies depending on the
type of device used. Any moisture condensation or drying of the solid layer is avoided;
Procedure. Place the electrolyte solution in the electrode compartments. Place the support,
conveniently soaked with the electrolyte solution in the tank, according to the type of device used.
Plot the starting line and apply the test sample. Allow the current to pass for the indicated time; then
turn off the power, remove the tank support, dry and reveal.
In cylindrical tube polyacrylamide gel electrophoresis, the stationary phase consists of a gel prepared
from acrylamide and N,N'-methylenebisacrylamide. The gels are prepared in tubes, usually 7.5 cm in
length and 0.5 cm in internal diameter (cylindrical gel); a single sample is applied to each tube.
Apparatus. The apparatus consists of two containers intended to receive the buffer solutions and made
of suitable material, such as polymethyl methacrylate. They are arranged vertically one above the
other and are each equipped with a platinum electrode. These two electrodes are connected to a
current source, enabling operating with constant intensity and voltage. For cylindrical gels, the device
has, at the upper base of the reservoir, a number of elastomer joints located at equal distance from the
electrode.
Procedure. In general, it is recommended to degas the solutions before polymerization and use the
gel immediately after preparation. Prepare the gel as indicated in the monograph. Place the gel
mixture in the appropriate glass tubes, closed at the lower end with a stopper, to an equal height in all
of them, at a distance of about 1 cm from the upper edge of the tube. Avoid the introduction of air
bubbles into the tubes. Cover the mixture with a layer of water to prevent contact with air and allow
to stand. Gel formation generally requires about 30 minutes and is complete when a clear boundary
between the gel and the aqueous layer appears. Eliminate the aqueous layer. Fill the lower reservoir
with the prescribed buffer solution and remove the stoppers from the tubes. Fit the tubes into the
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.22-00
joints of the upper reservoir so that its lower part immerses in the buffer solution of the lower reservoir
and adjusts so that the bottom of the tubes is immersed in the buffer solution of the lower reservoir.
Gently fill the tubes with the solution from the lower reservoir. Prepare problem and standard
solutions containing the prescribed colorant. Carefully fill the tubes with the indicated buffer solution.
Apply the solutions, whose density has been increased, by adding sucrose, for example, to the gel
surface, using a different tube for each solution. Place the same buffer solution in the upper reservoir.
Connect the electrodes to the current source and proceed with electrophoresis, using current of
constant intensity or voltage and at the temperature prescribed in the monograph. Stop the current
when the colored indicator reaches the lower reservoir. Immediately remove the tubes and proceed
with the gel extrusion. Locate the position of the bands on the electrophoretograms according to the
indicated procedure.
Application field. Polyacrylamide gel electrophoresis is used for the qualitative characterization of
proteins contained in biological preparations, for purity controls and quantitative determinations.
Purpose. The analysis by gel electrophoresis is a process adapted to the identification and control of
the homogeneity of proteins contained in pharmaceutical preparations. It is routinely used to assess
the molar mass of protein subunits and determine the subunits that compose the purified proteins.
There is a wide variety of ready-to-use gels and reagents on the market instead of those described
below, provided that the results obtained are equivalent and that the validity conditions described in
Assay Validation can be met.
Characteristics of polyacrylamide gels. The sieving properties of polyacrylamide gels are related to
their particular structure, which is that of a three-dimensional network of fibers and pores resulting
from the formation of cross-links between the bifunctional bisacrylamide and adjacent
polyacrylamide chains. The polymerization is catalyzed by a free radical generator composed of
ammonia persulfate (APS) and N,N,N',N'-tetramethylethylenediamine (TEMED). The smaller the
actual pore size of a gel the higher its concentration of acrylamide. As the gel acrylamide
concentration increases, the effective porosity decreases. The actual porosity of a gel is operationally
defined by its molecular sieving properties, that is, the resistance it opposes to the migration of
macromolecules. There are limits to the concentrations of acrylamide that can be used. At very high
concentrations gels break down more easily and become difficult to manipulate. When the pore size
of a gel decreases, the rate of migration of a protein in that gel decreases as well. By adjusting the
porosity of a gel by changing the acrylamide concentration, it is possible to optimize the method
resolution for a given protein product. Accordingly, the physical characteristics of a gel therefore
depend on its acrylamide and bisacrylamide content. In addition to the gel composition, the state of
the protein is another important factor for its electrophoretic mobility.
In the case of proteins, electrophoretic mobility depends on the pKa of the cleavable groups and the
size of the molecule. It is also affected by the nature, concentration and pH of the buffer, the
temperature, the intensity of the electric field and the nature of the support.
The method described as an example is applicable to the analysis of polypeptides with a molar mass
of between 14.000 and 100.000 daltons. It is possible to extend this range through different methods
(for example, using gradient gels or special buffer systems), but these are not part of this text.
Polyacrylamide gel electrophoresis under denaturing conditions using sodium dodecyl sulfate (SDS-
PAGE) is the most widely used electrophoresis method to assess the pharmaceutical quality of protein
products and is primarily the focus of this text. In general, analytical protein electrophoresis is
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.22-00
performed on a polyacrylamide gel under conditions that favor the dissociation of proteins into their
polypeptide subunits and that limit the aggregation phenomenon. Sodium dodecyl sulfate (SDS), a
strong anionic detergent, is often used to dissociate proteins prior to application to the gel, in
combination with heat. Denatured polypeptides bind to SDS and acquire negative charges, being
characterized by a constant charge/mass ratio, regardless of the type of protein considered. Since the
amount of SDS bound is almost always proportional to the molar mass of the polypeptide and
independent of its sequence, SDS-polypeptide complexes migrate in polyacrylamide gels with
mobilities that are a function of the size of the polypeptide.
The electrophoretic mobility of the resulting detergent-polypeptide complexes always has the same
functional relation with molar mass. The migration of the SDS complexes is, as expected, towards
the anode at a higher velocity for the low molar mass complexes than for the high ones. It is, therefore,
possible to determine the molar mass of a protein from its relative mobility, after comparison with
standard solutions of known molar mass value with the observation of a single band constituting a
purity criterion. However, eventual modifications in the constitution of the polypeptide, for example,
an N- or an O-glycosylation, have a significant impact on the apparent molar mass of a protein since
SDS does not bind to a carbohydrate medium in a similar manner it does to a polypeptide. In fact,
SDS does not bind in the same manner to glycidic groupings or to peptide groupings, so that the
constancy of the charge/mass ratio is no longer verified. The apparent molar mass of proteins that
have undergone post-translational modifications does not really reflect the mass of the polypeptide
chain.
Reducing conditions
The association of polypeptide subunits and the three-dimensional structure of proteins are often
based on the existence of disulfide bridges. One of the objectives to be achieved in the SDS-PAGE
analysis under reducing conditions is to break this structure by reducing the disulfide bridges.
Complete denaturation and dissociation of proteins by treatment with 2-mercaptoethanol or with
dithiothreitol (DTT) causes a splitting of the polypeptide chain, followed by a complexation with
SDS. Under these conditions, the molar mass of the polypeptide subunits can be calculated by linear
regression with the aid of appropriate molar mass standards.
Non-reducing conditions
For certain analyses, complete dissociation of the protein into peptide subunits is not desirable. In the
absence of treatment by reducing agents such as 2-mercaptoethanol or DTT, the covalent disulfide
bonds remain intact and the oligomeric conformation of the protein is preserved. SDS-oligomer
complexes migrate more slowly than SDS-peptide subunits. Furthermore, unreduced proteins may
not be fully saturated in SDS and therefore do not bind to detergent in a constant mass ratio. This
circumstance makes the determination of the molar mass of these molecules by SDS-PAGE more
difficult than the analysis of fully denatured polypeptides, as, for comparison to be possible, it is
necessary that the standards and unknown proteins have similar configurations. However, obtaining
a single stained band on the gel remains a criterion for purity.
The most widespread electrophoretic method for the characterization of complex protein mixtures is
based on the use of a discontinuous buffer system that includes two continuous but distinct gels: a
separation or resolving gel (lower) and a stacking gel (upper) . These two gels have different porosity,
pH and ionic strength. In addition, different mobile ions are used in gels and electrode buffers. The
discontinuity of the buffer system leads to a large volume concentration of samples in the
concentrating gel and therefore an improvement in resolution. When the electric field is applied, a
negative voltage gradient builds up through the sample solution and carries proteins from the
concentration gel to the stacking gel. The glycinate ions contained in the electrode buffer follow the
proteins in the stacking gel. A mobile division zone quickly forms, the front of which made of the
highly mobile chloride ions and the back of the slower glycinate ions. A localized high voltage
gradient establishes itself between the ionic fronts of the head and tail and causes the SDS-protein
complexes to concentrate in a very narrow range that migrates between the chloride and glycinate
fractions.
On a large scale, regardless of the volume of sample applied, the set of SDS-protein complexes
undergoes a condensation effect and penetrates the separation gel in the form of a narrow, well-
defined, high- protein density band. The large-pore stacking gel does not generally slow down the
migration of proteins, but mainly plays the role of an anti-convective medium. At the interface of the
stacking and separating gels, proteins are confronted with a sharp increase in the lag effect due to the
small pore diameter of the separating gel. When they penetrate the separation gel, this delay proceeds
due to the molecular slurry effect exerted by the matrix. The glycinate ions pass through the proteins
whose migration then proceeds in a medium of uniform pH consisting of a buffered tromethamine
solution (TRIS) and glycine. The molecular slurry effect leads to a separation of the SDS-polypeptide
complexes based on their respective molar mass.
Mold assembly
With a mild detergent, clean the two glass plates (e.g. 10 cm x 8cm size), the polytetrafluoroethylene
comb, the two spacers and the silicone rubber tube (e.g. 0.6 mm x 350 mm diameter), and rinse
thoroughly with water. Dry all elements with a paper towel or fabric. Lubricate spacers and tube with
non-silicone based lubricant. Place the spacers 2 mm from the edge along the two short sides and one
of the long sides of the glass plate. The latter will correspond to the bottom of the gel. Start installing
the tube on the glass plate using one of the spacers as a guide. When the end of the spacer is reached,
carefully bend the tube so that it follows the long side of the glass plate. Hold the tube in place with
one finger, bend it again to make it follow the second short side of the plate, using the spacer as a
guide. Place the second plate in place, aligning it perfectly over the first, and hold the set by hand
pressure. Place two tweezers on each of the short sides of the mold and then, with caution, four more
tweezers on the long side that will form the base of the mold. Check that the tube follows the edge of
the plates and has not shifted after placing the clamps. The mold is ready and the gel can be placed.
Preparation of gels
For the gels in discontinuous buffer system, it is recommended to place the separating gel first and
allow to polymerize before placing the concentration gel, since the content of acrylamide-
bisacrylamide in the two gels, the buffer and the pH are different.
Preparation of the separation gel. In an Erlenmeyer flask, prepare the appropriate volume of an
acrylamide solution of the desired concentration, using the values indicated in Table 1. Mix the
components in the order given. Before adding the ammonia persulfate solution and the
tetramethylethylenediamine (TEMED) solution, filter, if necessary, by suction, using a cellulose
acetate membrane (pore diameter 0.45,μm); keep under suction, shaking the filter unit until no more
bubbles form in the solution. Add the appropriate amounts of APS and TEMED solution (Table 1),
shake and immediately introduce into the space separating the two glass plates of the mold. Leave
enough free height for the concentration gel (height of a comb tooth plus 1 cm). Using a tapered glass
pipette, carefully cover the solution with water-saturated isobutyl alcohol. Allow the gel to
polymerize in an upright position at room temperature.
Preparation of the stacking gel. When polymerization is complete (about 30 minutes), exhaust the
isobutyl alcohol and wash the gel surface several times with water to completely eliminate the
isobutyl alcohol and, if necessary, the unpolymerized acrylamide. Place a minimum amount of liquid
on the gel surface and, if necessary, absorb the residual water with the tip of a paper towel. In an
Erlenmeyer flask, prepare the appropriate volume of an acrylamide solution of desired concentration,
using the values indicated in Table 2. Mix the components in the order given.
Before adding the ammonia persulfate solution (APS) and the tetramethylethylenediamine (TEMED)
solution, filter, if necessary, by suction, using a cellulose acetate membrane (pore diameter 0.45,μm);
keep under suction, shaking the filter unit until no more bubbles form in the solution. Add the
appropriate amounts of ammonia persulfate and TEMED solutions (Table 2), shake and immediately
add onto the separating gel. Immediately place a clean polytetrafluoroethylene comb in the
concentration gel solution, taking care to avoid the formation of air bubbles. Add the solution to the
concentration gel to completely fill the comb interstices. Allow the gel to polymerize in an upright
position at room temperature.
When polymerization is complete (about 30 minutes), carefully remove the comb. Wash the wells
immediately with water or SDS-PAGE electrophoresis buffer to remove any unpolymerized
acrylamide. If necessary, straighten the teeth from the stacking gel with a blunt tip hypodermic needle
attached to a syringe on one of the short sides of the plate, carefully remove the tube and place the
clamps back. Proceed in the same manner on the other short side and then at the base of the mold.
Introduce the gel into the electrophoresis device.
Insert the electrophoresis buffers into the upper and lower reservoirs. Eliminate any bubbles trapped
in the base of the gel between the glass plates. It is recommended to use a bent hypodermic needle
attached to a syringe for this purpose. Never establish electrical voltage on the gel without the
samples, as this can destroy the discontinuity of the buffer system. Before depositing the sample,
wash or fill the wells with caution with SDS-PAGE electrophoresis buffer. Prepare problem and
standard solutions using the recommended sample buffer and handle them as specified in the analyte
monograph. Apply the appropriate volume of the different solutions to the concentration gel wells.
Carry out electrophoresis under the conditions recommended by the device manufacturer. Certain
manufacturers of SDS-PAGE devices provide gels of various surfaces and thicknesses. To obtain an
optimal separation, it may be necessary to vary the electrophoresis duration and electrical parameters
as indicated by the manufacturer. Check that the staining front moves on the separating gel; if it
reaches the base of the gel, stop the electrophoresis. Remove the mold from the appliance and separate
the two glass plates. Remove the spacers, separate and discard the stacking gel and proceed
immediately to staining.
Coomassie blue staining is the most frequently used method for protein detection, with a detection
level of 1µg to 10µg of protein per band. Silver nitrate staining is the most sensitive method for
visualizing proteins in gels; it enables detection of bands with 10 ng to 100 ng of protein. All gel
staining steps are carried out at room temperature, with moderate agitation and orbital movement in
appropriate device. Gloves must be worn to avoid depositing fingerprints on the gel that would also
be stained.
Coomassie blue staining. Soak the gel for at least one hour in a large excess of Coomassie blue RS.
Discard the staining solution. Dip the gel in a large excess of bleach solution (consists of a mixture
of one volume of glacial acetic acid, four volumes of methyl alcohol and five volumes of water).
Renew the bleaching solution several times until the protein bands clearly appear on a light
background. The stronger the gel discoloration, the less protein will be detected by this method. It is
possible to accelerate the discoloration by incorporating a few grams of ion exchange resin or a
sponge into the bleaching solution.
Note: The acid-alcoholic solutions used in this method do not fully bind the gel proteins. There may
therefore be a loss of certain low molar mass proteins during the staining and bleaching operations
of thin gels. Permanent fixation can be achieved by placing the gel for one hour in a mixture of one
volume of trichloroacetic acid, four volumes of methyl alcohol and five volumes of water, before
dipping into the Coomassie Blue RS Solution.
Staining with silver nitrate. Immerse the gel for one hour in a large volume of fixing solution (consists
of adding 0.27 mL of formaldehyde in 250 mL of methyl alcohol and diluting to 500 mL with water).
Discard and renew the fixation solution and allow to incubate for at least one hour, or overnight if
more practical. Discard the fixation solution and place the gel in an excess volume of water for one
hour, then soak for 15 minutes in 1% (v/v) glutaraldehyde solution. Wash the gel by placing it twice
in an excess volume of water for 15 minutes, then immerse it for 15 minutes, protected from light, in
fresh-prepared silver nitrate RS1. Wash the gel by placing it three times in an excess volume of water
for 15 minutes and then immerse it for about one minute in the development solution (consisting of
diluting 2.5 mL of 2% citric acid monohydrate (w/v) and 0.27 mL of formaldehyde in water and dilute
to 500 mL with water) until obtaining satisfactory color.
Suspend the development by immersion for 15 minutes in a 10% (v/v) acetic acid solution. Wash
with water.
The treatment of gels is slightly different depending on the staining method used. In Coomassie
staining, the discoloration step is followed by immersion of the gel in a 10% (w/v) glycerol solution
for at least two hours (or overnight). In silver staining, the final wash is followed by immersion in a
2% (w/v) glycerol solution for five minutes. Soak two sheets of porous cellulose in water for five to
ten minutes. Place one of the sheets in a drying frame. Gently lift the gel and place on the cellulose
sheet. Eliminate any bubbles that may have been trapped and add a few milliliters of water along the
edges of the gel. Cover with the second sheet and remove any trapped air bubbles. Finish the drying
frame assembly. Place in the oven or allow to dry at room temperature.
The molecular mass of proteins is determined by comparing their mobility with the mobility of several
known protein molecular mass markers. For the standardization of gels, there are mixtures of proteins
of exactly known molecular masses that allow for obtaining a uniform coloration. Such blends are
available for different molecular weight ranges. Concentrated stock solutions of proteins of known
molecular weight are diluted in buffer for appropriate sampling and deposited on the same gel as the
protein sample to be examined. Immediately after electrophoresis, determine the exact position of the
marking dye (bromophenol blue) to identify the ion migration front. For this purpose, a small portion
of the gel edge can be cut, or a needle wet in Indian ink can be dipped into the gel, at the level of the
dye migration front. After staining the gel, determine the migration distance of each protein band
(markers and unknown bands) from the upper edge of the separating gel and divide each of these
migration distances by the distance traveled by the marking dye. The migration distances thus
obtained are called relative protein mobilities (in reference to the staining front) and are
conventionally represented by Rf. Plot a graph using the logarithms of the relative molecular mass
(Mr) of the protein standards versus the corresponding Rfs. The graphics obtained are slightly
sigmoid. The calculation of unknown molecular masses can be performed by linear regression, or by
interpolation from the log variation curve (Mr) as a function of the Rf, as long as the values obtained
for the unknown samples are located in the linear part of the graph.
Test validation
The test will only be valid if the proteins used as molecular mass markers are distributed over 80%
of the length of the gel and if, within the desired separation range (for example, the range that covers
the product and the dimer, or the product and the related impurities) there is for the protein bands
concerned a linear relation between the log of molecular mass and the Rf value. Supplementary
validation requirements regarding sample preparation may be specified in particular monographs.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.22-00
GENERAL PRINCIPLES
In CE, separation is governed by two factors. The first corresponds to the movement of solutes in the
capillary due to the electric field (E), also called electrophoretic velocity. The second occurs as a
function of the electrolyte flow due to the charged surface on the capillary wall, being called
electroosmotic flow. The electrophoretic mobility of a solute (μep) is related to specific characteristics
such as molecular size, shape and electrical charge, as well as the inherent properties of the electrolyte
in which migration occurs (electrolyte ionic strength, pH, viscosity and presence of additives). Under
the influence of voltage, charged solutes migrate through the electrolyte with a given velocity, Vep,
given in cm/s, and calculated by the formula:
𝑞 𝑉
𝑉𝑒𝑝 = 𝜇𝑒𝑝 ∙ 𝐸 = ( )( )
6𝜋𝜂𝑟 𝐿
where
𝜇𝑒𝑝 =electrophoretic mobility;
E = applied voltage;
q = effective charge of the solute;
η = electrolyte viscosity;
r = Stokes radius;
V = voltage applied to the system;
L = total capillary length.
When an electric field is applied across the capillary, an electrolyte flow is generated inside the
capillary. The migration of different solutes along the capillary towards the detector, regardless of the
presence of ionic charge, indicates that in addition to electrophoretic mobility, an additional force is
involved. Without this additional force, positively charged compounds would migrate through the
capillary while the anions would remain at a distance from the detector and the neutral solutes would
simply not migrate. The additional force that directs all solutes through the capillary is called
electroosmotic flow (EOF) and plays an important role in different types of CE.
EOF originates from the ionization of the silanol groups in the inner wall of the capillary, which are
transformed into silanoate groups (Si-O-), at a pH above three. These negatively charged groups
attract the electrolyte cations, forming an inner layer on the capillary wall. The double layer formed
near the capillary surface is essentially static. The more diffuse layer, close to the double layer, is
mobile and, under the action of an electrical voltage, migrates towards the cathode, carrying the
hydration water together. Between the two layers there is a friction plane and the electrical imbalance
generated corresponds to the potential difference that crosses the two layers, called zeta potential (ζ).
The speed of the electroosmotic flow is dependent on the electroosmotic mobility (μeo) which, in
turn, is directly related to the charge density of the inner wall of the capillary and the characteristics
of the electrolyte. The velocity of the electroosmotic flow (Veo) can be calculated by the formula:
𝜀∙ζ 𝑉
𝑉𝑒𝑜 = 𝜇𝑒𝑜 ∙ 𝐸 = ( )( )
𝜂 𝐿
where
𝜀 = electrolyte dielectric constant;
ζ = capillary surface zeta potential;
η = electrolyte viscosity;
V = voltage applied to the system;
L = total capillary length.
The electrophoretic and electroosmotic mobilities of a solute can act in the same direction or in
opposite directions, depending on the charge (positive or negative) of the solute and the speed of the
solute (v), according to the formula below:
𝑉 = 𝑉𝑒𝑝 ± 𝑉𝑒𝑜
The sum or difference between the two speeds is used depending on whether the mobilities act in the
same direction or in opposite directions. In capillary electrophoresis, in its most usual form, anions
will migrate in the opposite direction to the electroosmotic flow and their velocities will be lower
than the velocity of the electroosmotic flow. Cations will migrate in the same direction as the
electroosmotic flow and their velocities will be higher than the velocity of the electroosmotic flow.
In this condition, in which there is a fast electroosmotic flow velocity in relation to the electrophoretic
velocity of solutes, cations and anions can be separated in the same electrophoretic run.
The time (t) required for the solute to migrate a distance (l) from the capillary injection terminal to
the capillary detection window (effective capillary length) is defined by the formula:
𝑙 𝑙(𝐿)
𝑡= =
𝑉𝑒𝑝 ± 𝑉𝑒𝑜 𝑉(𝑈𝑒𝑝 ± 𝑈𝑒𝑜 )
where
l = distance from the capillary injection terminal to the capillary detection window (effective capillary
length);
Vep =electrophoretic speed;
Veo = speed of electroosmotic flow.
The reproducibility of solute migration speed is directly related to the maintenance of a constant value
of the electroosmotic flux between different electrophoretic runs. For some specific applications, it
may be necessary to reduce or even suppress the electroosmotic flow through changes in the capillary
wall or in the concentration, composition and/or pH of the electrolyte solution.
After introducing the sample into the capillary, each sample solute migrates along with the electrolyte
as an independent band, according to its intrinsic mobility. Under ideal conditions, the only factor
that can contribute to the widening of the band comes from the molecular diffusion of the solute along
the capillary (longitudinal diffusion). In this case, the band performance is expressed as the number
of theoretical plates (N) according to the formula:
where
D = molecular diffusion coefficient of the solute in the electrolyte;
The separation between two bands can be achieved by modifying the electrophoretic mobility of the
solutes, by the electroosmotic flow and by increasing the performance of the bands of each solute
under analysis. The resolution can be calculated by the formula:
√𝑁(𝜇𝑒𝑝𝑏 − 𝜇𝑒𝑝𝑎 )
𝑅𝑠 =
4(𝜇𝑒𝑝 + 𝜇𝑒𝑜 )
where
μepa and μepb = electrophoretic mobilities of two solutes to be separated;
μeo= mobility of electroosmotic flow;
𝜇 −𝜇𝑒𝑝𝑎
μep= average electrophoretic mobility of solutes( 𝑒𝑝𝑏 2 )
APPARATUS
- two electrolyte reservoirs, kept at the same level, containing anodic and cathodic solutions;
- two electrodes (cathode and anode), immersed in the electrolyte reservoirs and connected to the
high voltage source;
- a fused silica capillary provided with a detection window for alignment to certain types of
detectors. The capillary ends are immersed in the reservoirs containing the electrolyte solutions. The
capillary must be filled with the electrolyte solution prescribed in the monograph;
- system for injection of the solute(s) sample by hydrodynamic or electrokinetic action. The choice
of the injection process and its automation are essential in quantitative analysis by capillary
electrophoresis. The introduction of the sample through the electrokinetic mode must take into
account the intrinsic electrophoretic mobility of each solute, allowing adequate discrimination of the
different components of the sample;
- detector capable of monitoring the amount of solutes that pass through the capillary detection
segment in a specific time range. The most common detectors are based on absorption
spectrophotometry (UV and UV-VIS) or fluorimetry. Analyses can also be carried out using
electrochemical detectors or by coupling with mass spectrometry;
- temperature control system capable of keeping it constant inside the capillary. Changes in
temperature imply a lack of reproducibility in the separation of solutes;
The monograph for each substance should detail the capillary type, electrolyte solutions,
preconditioning method, sample conditions and electrophoretic migration.
The electrolyte solution must be filtered (0.45µm filter) to remove particles and de-aerated to avoid
the formation of bubbles that could interfere with the detection system or break electrical contact in
the capillary during electrophoretic migration. Electrophoretic methods must establish a detailed
capillary washing procedure between each run to allow reproducible migration times of the solutes
under analysis.
In this method, solutes are separated in a capillary containing only electrolyte, without any
anticonvective medium. The separation mechanism is based on the differences presented by the
charge/mass ratio of the analyzed species that migrate as bands at different speeds. Solutes are
separated by the combination of intrinsic electrophoretic mobility and the magnitude of
electroosmotic flow in the capillary. Internally coated capillaries, with reduced electroosmotic flow,
can be used to increase the separation capacity of solutes that adsorb on the capillary surface.
The free solution method is suitable for the analysis of low molecular mass (PM < 2000) and high
molecular mass (2000 < PM < 100 000) solutes. Due to the high performance of the system, molecules
with minimal differences in their mass/charge ratio can be discriminated. The method also allows for
the separation of chiral solutes by adding chiral selectors to the separation electrolyte. Separation
optimization requires the evaluation of different instrumental and electrolyte solution-related
parameters.
INSTRUMENTAL PARAMETERS
Voltage – the separation time is proportional to the applied voltage. However, an increase in the
voltage used can cause excessive heat production (Joule effect), causing an increase in temperature
and viscosity gradients in the electrolyte inside the capillary, which are responsible for widening the
band and reducing the resolution of the solutes under analysis;
Polarity – electrode polarity can be normal (inlet anode and outlet cathode). In this case the
electroosmotic flow moves towards the cathode. If the electrode polarity is reversed, the direction of
the electroosmotic flow is opposite to the exit and only charged solutes with electrophoretic mobility
greater than that of the electroosmotic flow migrate towards the exit;
Temperature – the main effect of temperature is observed on the viscosity and electrical conductivity
of the electrolyte. Changes in these two electrolyte properties determine differences in migration
speed;
Capillary – the length and internal diameter influence analytical parameters such as total solute
migration time, separation performance and loading capacity. Under constant voltage, the increase in
the total and effective length of the capillary can reduce the electrical current, which, in turn,
determines the increase in the migration time of the analytes. Capillaries with a smaller internal
diameter have a better capacity to dissipate the heat generated by the electrical current (Joule effect),
allowing for an increase in the applied voltage and a reduction in the analysis time. The detection
limit of the method can also be influenced by the internal diameter, depending on the injected sample
volume and the detection system used. The performance of separations can also be increased by
reducing the internal diameter of the capillary.
Adsorption of sample components to the inner wall of the capillary can limit performance. For this
reason, strategies to avoid these interactions should be considered when developing a capillary
electrophoresis separation method. This is a critical factor, for example, in samples containing
proteins. One of these strategies (using extreme pH(s) and adsorption of positively charged
electrolytes) requires modifying the electrolyte composition to prevent adsorption of proteins.
Alternatively, it is possible to cover the inner wall of the capillary with a polymer through covalent
bonds, preventing the interaction of proteins with the surface of the negatively charged silica. For this
proposal, capillaries with the inner wall previously covered with polymers of neutral-hydrophilic,
cationic and anionic nature are commercially available.
Buffer nature and concentration – Electrolytes for capillary electrophoresis must have adequate
buffering capacity in the chosen pH range and low mobility, in order to minimize the generation of
electrical current. To decrease the distortion of the electrophoretic peak, matching the mobility of the
electrolyte ion with the mobility of the solute is required. The choice of sample solvent is important
to achieve solute uniformity, which allows for increased separation performance and improved
detection. Furthermore, an increase in the concentration of the electrolyte at a specific pH determines
a decrease in the electroosmotic flow and solute velocity.
Electrolyte pH – The pH of the electrolyte can affect separation by modifying the charge of solute or
other additives, as well as altering the electroosmotic flow. The change in the pH value of the
electrolyte above or below the isoelectric point of proteins and peptides influences the separation of
these solutes, by changing the net charge from negative to positive. In general, an increase in the
electrolyte pH causes an increase in the electroosmotic flow.
Organic solvents – Organic solvents, such as methyl alcohol, acetonitrile, among others, can be added
to the aqueous electrolyte to increase the solubility of the solute and/or other additives present in the
electrolyte, or even influence the degree of ionization of the solutes in the sample. The addition of
these solvents to the electrolyte usually causes a reduction in the electroosmotic flow.
Additives for chiral separations – Enantiomeric separations should be carried out by adding chiral
selectors to the running electrolyte. The most used chiral selectors are cyclodextrins. However, crown
ethers, polysaccharides and proteins can also be used for this purpose. Enantiomeric discrimination
is governed by different interactions between the chiral selector and each of the enantiomers of the
solute under analysis. Accordingly, the correct choice of the selector directly influences the
enantiomeric resolution obtained for chiral solutes. During the development of a method for
enantiomeric separation, it is recommended to test cyclodextrins of different cavity sizes, (a, b, g),
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.22-00
cyclodextrins modified with neutral groups (methyl, ethyl, hydroxyalkyl, etc.), or with ionizable
groups (aminomethyl , carboxymethyl, sulfobutylether, etc.). The resolution of chiral separations is
also controlled by the concentration of the chiral selector, the composition and pH of the electrolyte,
and the analysis temperature. Organic additives such as methyl alcohol and urea can be used to modify
the obtained resolution.
At neutral or alkaline pH, a strong electro-osmotic flow is generated, moving the separating
electrolyte ions towards the cathode. If SDS is used as a surfactant, the electrophoretic migration of
the anionic micelle will be in the opposite direction, towards the anode. As a result, the total micellar
migration speed is reduced compared to the flow of the electrolyte solution. In neutral solutes, since
the analyte can be distributed between the micelle and the electrolyte, and there is no electrophoretic
mobility, the rate of migration of the analyte will only depend on the partition coefficient between the
micelle and the electrolyte. In the electropherogram, the peaks corresponding to each neutral solute
are always located between the electroosmotic and micelle flow marker (the time between these two
peaks is called separation window). For ionized solutes, the migration speed depends on the partition
coefficient of the solute between micelle and electrolyte and on the electrophoretic mobility of the
solute in the absence of the micelle.
In MEKC, the mechanism of neutral and weakly ionized solutes is essentially chromatographic.
Therefore, solute migration and resolution can be represented in terms of the solute retention factor
(k), also called the mass distribution ratio (Dm), which is the ratio between the number of moles of
the solute within the micelle and in the mobile phase. For a neutral substance, k can be calculated
using the following formula:
𝑡𝑅 − 𝑡0 𝑉𝑆
𝑘= 𝑡 = 𝐾 ×
𝑡0 × (1 − 𝑡 𝑅 ) 𝑉𝑀
𝑚𝑐
where
𝑡𝑅 = solute migration time;
𝑡0 = migration time of an unretained solute (determined by injection of an electroosmotic flow marker
that does not bind to the micelle, e.g. methyl alcohol);
𝑡𝑚𝑐 = micelle migration time (determined by the injection of a micelle marker, such as Sudan III,
which continuously migrates associated with the micelle throughout the electrophoretic migration);
K = solute partition coefficient;
𝑉𝑆 = micellar phase volume;
𝑉𝑀 = mobile phase volume;
𝑡
√𝑁 𝛼 − 1 𝑘𝑏 1 − (𝑡 0 )
𝑚𝑐
𝑅𝑆 = × × ×
4 𝛼 𝑘𝑏 + 1 1 + 𝑘 ( 𝑡0 )
𝑎 𝑡
𝑚𝑐
where
N = Number of theoretical plates of each solute;
𝛼 = selectivity;
ka and kb = retention factors for both solutes respectively (kb > ka).
Similarly, but not identically, the formulas provide values of k and Rs for charged solutes.
OPTIMIZATION
The development of methods by MEKC involves instrumental and electrolyte solution parameters:
Instrumental parameters
Voltage – the separation time is inversely proportional to the applied voltage. However, an increase
in voltage can cause excessive heat production, increasing the temperature and viscosity gradients of
the electrolyte in the capillary cross-section. This effect can have a relevant impact on electrolytes
with higher conductivity, such as those containing micellar systems. Systems that have lower heat
dissipation capacity determine band broadening and lower resolution between peaks.
Temperature – Changes in capillary temperature affect the solute partition coefficient between the
electrolyte and micelles, the critical micelle concentration, and the electrolyte viscosity. These
parameters directly influence the solute migration time during electrophoretic separation. The use of
an adequate refrigeration system increases the reproducibility of solute migration time.
Capillary – Capillary dimensions (length and internal diameter) contribute to analysis time and
performance of separations. Under constant voltage, the increase in the total and effective length of
the capillary can decrease the electrical current, which, in turn, determines the increase in the
migration time of the analytes. The internal diameter of the capillary controls the dissipation of heat
(in a given electrolyte and electrical current) and consequently the widening of the solute bands.
Nature of the surfactant and concentration – The nature of the surfactant, analogous to the stationary
phase in chromatography, affects the resolution, as it modifies the selectivity of the separation. The
log k of a neutral substance increases linearly with the concentration of the surfactant in the mobile
phase. Since the resolution in MEKC reaches a maximum when k has a value close to
√𝑡𝑚𝑐 /𝑡0
Modifications in the concentration of surfactant present in the mobile phase determine changes in the
resolution of the bands.
Electrolyte pH – pH does not change the partition coefficient of non-ionized solutes, but may
determine changes in electroosmotic flow in uncoated capillaries. A decrease in electrolyte pH
reduces the electroosmotic flow, providing an increase in the resolution of neutral solutes and in the
analysis time.
Organic solvents – organic solvents (methyl alcohol, propanol, acetonitrile) can be added to the
electrolyte solution to improve the separation of hydrophobic solutes. In general, the addition of these
modifiers reduces migration time and separation selectivity. The percentage of added organic solvent
must take into account the critical micellar concentration of the surfactant, considering that excessive
values can affect or even inhibit the micelle formation process and, therefore, the absence of the
partition phenomenon. The dissociation of micelles in the presence of high percentages of modifier
does not necessarily mean better results in the separation. In certain situations, the hydrophobic
interaction between the surfactant monomer and neutral solutes form solvophobic complexes that can
be electrophoretically separated.
Modifiers for chiral separations – the separation of enantiomers in MEKC can be achieved through
the inclusion of chiral selectors to the micellar system, covalently linked to the surfactant or added to
the separation electrolyte. Micelles that have bonds with chiral discrimination properties include salts
of N-dodecanoyl-L -amino acids, bile salts, among others. Chiral resolution can also be achieved
through chiral selectors, such as cyclodextrins, added directly to electrolyte solutions containing non-
chiral surfactants.
Other Additives – Selectivity can be modified through various strategies, by adding chemicals to the
electrolyte. The addition of several types of cyclodextrins to the electrolyte can also be used to reduce
the interaction of hydrophobic solutes with the micelle, thus increasing the selectivity for this type of
solute.
The addition of substances capable of modifying the solute-micelle interactions by adsorption in the
latter has been used to increase the selectivity of separations in MEKC. These additives can be a
second surfactant (ionic or non-ionic) that originate a mixture of micelles or metallic cations that
dissolve the micelle forming coordination complexes with the solutes.
QUANTIFICATION
The areas under the peaks must be divided by the corresponding migration time to provide the correct
area in order to:
- compensate for the shift in migration time between runs, thus reducing response variation;
- compensate for the different responses of the sample components with different migration times.
When an internal standard is used, it must be verified that no solute peak to be analyzed overlaps with
the peak of the internal standard.
CALCULATIONS
The content of the component (or components) under analysis must be calculated from the values
obtained. When prescribed, the percentage content of one or more components of the sample to be
analyzed is calculated by determining the corrected area(s) of the peak(s) as a percentage of the total
corrected areas of all peaks, excluding those resulting from solvents or added reagents
(standardization process). It is recommended to use an automatic integration system (integrator or
data acquisition and processing system).
SYSTEM SUITABILITY
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.22-00
The suitability parameters of the system are used to verify the behavior of the method by capillary
electrophoresis. The choice of these parameters depends on the type of Capillary Electrophoresis
used. The factors are: retention factor (k) (only for micellar electrokinetic chromatography), apparent
number of theoretical plates (N), symmetry factor (As) and resolution (Rs). The formulas that allow
you to calculate the values of N and Rs through the electropherograms are given below.
The apparent number of theoretical plates (N) can be calculated using the expression:
𝑡𝑅
𝑁 = 5,54 × ( ) ²
𝑤ℎ
where
𝑡𝑅 = migration time or distance from the baseline from the injection point to the perpendicular line
of the maximum point of the peak corresponding to the component;
𝑤ℎ = peak width at half height
Resolution
The resolution (Rs) between peaks of similar heights of 2 components can be calculated using the
expression:
where
tR1 andtR2 = migration times or baseline distances from the injection point to the perpendicular line
of the maximum point of two adjacent peaks
wh1 and wh2 = peak width at half height
Where appropriate, resolution can be calculated by measuring the valley height (Hv)between 2
partially resolved peaks in a standard preparation and the height of the smaller peak ( (Hp), calculating
the peak/valley ratio (p/v) :
𝑝 𝐻𝑝
=
𝑣 𝐻𝑣
Symmetry factor
The symmetry factor (As) of a peak can be calculated using the expression:
𝑤0,05
𝐴𝑆 =
2𝑑
where
w0.05 = peak width determined at 5% of height value;
d = distance between the perpendicular line of the maximum peak and the tangent of the peak at 5%
of the height of the peak.
Tests for area repeatability (standard deviation of areas or the area/migration time ratio) and for
migration time repeatability (standard deviation of migration time) are introduced as suitability
parameters. The repeatability of the migration time provides a test for the adequacy of capillary
washing procedures. An alternative practice to avoid lack of repeatability of the migration time is to
use the migration time relative to an internal standard.
A test to check the signal-to-noise ratio of a standard preparation (or determination of the limit of
quantification) can also be useful for the determination of related substances.
The limits of detection and quantification correspond to the signal:noise ratio of 3 and 10,
respectively. The signal:noise ratio (S/N) is calculated using the expression:
𝑆 2𝐻
=
𝑁 ℎ
where
H = peak height corresponding to the specific component, in the electropherogram obtained with the
reference solution, measured from the peak maximum to the extrapolated baseline of the observed
signal over a distance equal to 20 times the width at half height of the peak;
h = baseline range in an electropherogram obtained after blank injection, observed at a distance equal
to 20 times the width at half height of the peak in the electropherogram obtained with the reference
solution, and if possible, located close to the retention time where this peak would be found.
CHIRAL DRUGS
Enantiomers generally exhibit different pharmacological and toxicological properties as the main
molecular targets, such as proteins, nucleic acids and polysaccharides, are chiral. For example, the
methyl ether enantiomers of levorphanol, dextromethorphan and levomethorphan are used differently
in therapy. While dextromethorphan is indicated as an antitussive, levomethorphan is indicated as an
analgesic.
Due to the recognition of the importance of the clinical use of enantiomerically pure drugs in the
treatment of several diseases, pharmaceutical laboratories are constantly encouraged to make
resolved drugs available in industrial quantities.
To ensure the safety and efficiency of drugs available and under development, it is necessary to
resolve the enantiomers and examine each one for pharmacological and toxicological activities. After
identifying the most active enantiomer (eutomer), the enantiomeric excess of the eutomer from
synthesis to consumption must be evaluated to ensure the quality of the drug.
HPLC is considered one of the most efficient methods for the separation, detection and quantification
of drugs. The use of adequate chiral stationary phase (CSP) becomes a powerful method for the
separation of enantiomers.
The chromatographic resolution of enantiomers can be achieved by several methods, however, the
use of some type of discriminator or chiral selector is always required. The indirect and direct methods
are the two manners to separate the enantiomers using liquid chromatography.
In the indirect method, enantiomers are converted to diastereoisomers by reaction with a chiral
substance. Diastereoisomers are substances that have different physicochemical properties and,
therefore, can be separated using a non-chiral stationary phase.
The indirect method was widely used in the past. However, it has limitations such as the need to
isolate the substance of interest and the related derivatization. These facts make it difficult to develop
the automated process for large numbers of samples. Furthermore, the enantiomeric purity of the
derivatizing agents is important to avoid false results. Another limitation is the different reaction rates
and/or constants for the enantiomers since the reaction transition states are diastereoisomeric, which
can result in a different proportion of the initial enantiomeric composition.
In the direct method, the mixture of enantiomers to be resolved is injected directly into the
chromatograph. For the separation of the enantiomers, a CSP, a chiral solvent, or a mobile phase
with a chiral additive can be used. Resolution occurs due to the formation of diastereoisomeric
complexes between the enantiomeric mixture and the chiral selector used for resolution. The use of
CSP is currently the most used method for resolution by HPLC.
In the following tables (Tables 1, 2, 3, 4 and 5) the main classes of stationary phases used for the
resolution of racemic mixtures and some examples of chiral selectors in each class are presented.
Consult the manufacturer for indication of the use of each selector.
Chiral discriminator
Vancomycin
Teicoplanin
Ristocetin
Chloride and ammonium ions are some of the main impurities found in water and also influence its
conductivity. These external ions can significantly impact the chemical purity of water and
compromise its use in pharmaceutical applications.
The combined conductivities of dry intrinsic ions and external ions vary according to pH and are the
basis for the conductivity specifications described in Table 3 and used when running step 3 of the
test. Two preliminary steps are included in this test. If the test conditions and conductivity limits are
met in any of these preliminary steps (Steps 1 and 2), water meets the requirements of this test and
the application of Step 3 is not required. Only in case the sample does not meet the requirements of
Step 3, water is judged not to comply with the requirements of the conductivity test.
The conductivity of water must be measured using calibrated instruments with a resolution of
0.1 μЅ/cm. The thermometer should have 0.1°C divisions and cover the range of 23°C to 27°C.
Electrodes must be maintained as recommended by the device manufacturer.
The cell conductivity constant is a factor used as a multiplier for the conductivity meter scale values.
Cell constant: the value must be known in ±2%. Generally conductivity cells show constants of 0.1
cm-1, 1 cm-1 and 2 cm-1. Most devices show the defined cell constant. It is necessary to measure this
constant with the reference KCl solution described in Table 1. Verification is normally carried out
using only a reference solution; in this case, use the lowest conductivity reference solution. However,
it is recommended to periodically measure the conductivity of the other standards and observe the
agreement between the conductivity meter reading and the nominal value of each reference solution.
Calibration: as per manufacturer’s instructions. Since most multi-scale apparatus has a single
calibration point, calibration is required whenever you use a different scale. The reading obtained
must be within ±0.1 mS/cm of the nominal value of the reference solution.
To calibrate the conductivity meter, use the reference solutions described below.
Solution A (0.01 M): weigh exactly 0.7455 g of dry potassium chloride at 105 °C for two hours,
transfer to a 1000 mL volumetric flask, adjust volume with water and homogenize.
Solution B (0.005 M): pipet 50 mL of Solution A into a 100 mL volumetric flask, adjust with water
and homogenize.
Solution C (0.001 M): pipette 10 mL of Solution A into a 100 mL volumetric flask, adjust with water
and homogenize.
Solution D (0.0005 M): pipet 5 mL of Solution A into a 100 mL volumetric flask, adjust with water
and homogenize.
Solution E (0.0001 M): pipet 5 mL of Solution A into a 500 mL volumetric flask, adjust with water
and homogenize.
Note 1: for the preparation of the solutions above, always use carbon dioxide-free water with a
conductivity inferior to 0.10 μS.cm-1.
Note 2: Do not use temperature compensation and keep reference solutions at 25 °C during reading.
PROCEDURE
The procedure described below is established for measurements of purified water and water for
injections. Alternatively, Step 1 can be performed (with appropriate modifications, in accordance
with item 1 of Step 1) using "in-line" type instrumentation that has been properly calibrated, whose
cell constants have been exactly determined, and whose temperature compensation functions have
been disabled. The suitability of such “in-line” instruments for quality control testing is also
dependent on their location in the water system. Obviously, the placement of the instrument needs to
reflect the quality of the water that will be used.
Step 1
3 In Table 2, find the closest and lowest temperature value to the temperature at which the
conductivity was measured. The conductivity value corresponding to this temperature is the limit.
(Do not interpolate).
4 If the measured conductivity value is not greater than the corresponding value in Table 2, the water
meets the requirements for conductivity. However, if the measured value is greater than that in the
table, proceed with the determination according to Step 2.
Table 2 – Limit values for conductivity according to temperature (only for conductivity values without
temperature compensation).
Temperature (ºC) Conductivity (μЅ/cm)
0 0.6
5 0.8
10 0.9
15 1.0
20 1.1
25 1.3
30 1.4
35 1.5
40 1.7
45 1.8
50 1.9
55 2.1
60 2.2
65 2.4
70 2.5
75 2.7
80 2.7
85 2.7
90 2.7
95 2.9
100 3.1
Step 2
1 Transfer a sufficient amount of water (100 mL or more) to an appropriate container and shake
the sample. Adjust to (25 ± 1) °C and shake the sample vigorously, periodically observing the
conductivity meter reading. When the change in conductivity due to absorption of atmospheric carbon
dioxide is lower than 0.1 μЅ/cm for five minutes, record the conductivity.
2 If the conductivity is not higher than 2.1 μЅ/cm, the water meets the requirements for the
conductivity test. If the conductivity is higher than 2.1 μЅ/cm, proceed as per Step 3.
Step 3
Carry out this test maximum five minutes after Step 2 with the same sample, keeping temperature at
(25 ± 1) °C. Add saturated potassium chloride solution (0.3 mL for 100 mL of sample) and determine
the pH with an accuracy of 0.1 unit in accordance with Determination of pH (5.2.19). Using Table 3,
determine the limit value for conductivity according to pH.
Table 3 – Conductivity limit values according to pH (only for samples kept in balanced
atmosphere and temperature).
pH Conductivity (μЅ/cm)
5.0 4.7
5.1 4.1
5.2 3.6
5.3 3.3
5.4 3.0
5.5 2.8
5.6 2.6
5.7 2.5
5.8 2.4
pH Conductivity (μЅ/cm)
5.9 2.4
6.0 2.4
6.1 2.4
6.2 2.5
6.3 2.4
6.4 2.3
6.5 2.2
6.6 2.1
6.7 2.6
6.8 3.1
6.9 3.8
7.0 4.6
After determining the pH and establishing the limit according to Table 3, the water meets the test if
the conductivity measured in Step 2 is not greater than this limit. If the conductivity is higher or the
pH value is outside the range of 5 to 7, the water does not meet the test for conductivity.
ULTRAPURE WATER
For ultra-purified water, in general, conductivity meters or resistivity meters installed in water
purification device have a temperature compensation circuit for 25.0,°C and provide direct reading.
These devices must be periodically calibrated. The conductivity of ultrapurified water should be 0.055
µS/cm at 25.0°C (resistivity > 18.0 MOhm.cm) for a specific application.
Alternatively, if the apparatus does not provide a direct conductivity reading, proceed as follows:
2 Simultaneously determine the temperature and conductivity of the water without automatic
temperature compensation. The determination must be carried out in an appropriate container or
as an “in-line” determination. The value obtained must be less than 0.055 μS/cm, at a temperature
of (25.0 ± 0.1) ºC.
3 In Table 4, find the closest and lowest temperature value to the temperature at which the
conductivity was measured. The conductivity value corresponding to this temperature is the limit.
(Do not interpolate).
4 If the measured conductivity value is not greater than the corresponding value in Table 4, the water
meets the requirements for conductivity.
Table 4 – Limit values for conductivity according to temperature (only for conductivity values
without temperature compensation).
Temperature (ºC) Conductivity (μЅ/cm)
0 0.012
5 0.017
10 0.023
15 0.031
20 0.042
25 0.055
30 0.071
35 0.090
40 0.113
45 0.140
50 0.171
55 0.207
60 0.247
65 0,294
70 0.345
75 0.403
80 0.467
85 0.537
90 0.614
95 0.696
100 0.785
Use neutral, colorless and transparent glass tubes, with a flat bottom and 15 to 25 mm in internal
diameter, unless otherwise indicated in the monograph. Introduce, in separate tubes, the liquid under
examination and the reference suspension indicated in the monograph, preparing it during use, as
specified in Table 1. The liquid under examination and the reference suspension must reach, in the
tubes, a height of 40 mm. Five minutes after preparation of the reference suspension, compare the
contents of the tubes, observing them vertically, under diffused visible light and against a black
background. Light scattering must be such that the reference suspension I is easily distinguished from
water and reference suspension II.
A liquid is considered clear when, when examined under the conditions described above, its
transparency corresponds to that of the water or solvent used, or when its opalescence is not more
pronounced than that of the reference suspension I.
Opalescence standard
Dissolve 1 g of hydrazine sulfate in water, adjust volume to 100 mL with the same solvent and
homogenize. Allow to stand for four to six hours. Add 25 mL of this solution to a solution containing
2.5 g of methenamine in 25 mL of water. Mix well and allow to stand for 24 hours. This suspension
is stable for two months if kept in a glass container, with a surface free of defects. The suspension
must not adhere to the walls of the container and must be vigorously shaken in the original container
before use. To prepare the opalescence standard, dilute 15 mL of the suspension to 1000 mL with
water. The opalescence standard must be prepared at the time of use and can be kept for a maximum
of 24 hours.
5.2.26 ALCOHOLOMETRY
Alcoholometry is the determination of the alcoholic grading or ethanol content of mixtures of water
and ethyl alcohol.
The volumetric alcoholic grading of a mixture of water and alcohol is expressed by the number of
volumes of ethyl alcohol at 20°C contained in 100 volumes of this mixture at the same temperature.
It is expressed in % (v/v).
The weighed alcoholic grading is expressed by the ratio between the mass of ethyl alcohol contained
in a mixture of water and ethyl alcohol and its total mass. It is expressed in % (w/w).
Ethyl alcohol contains minimum 95.1% (v/v), corresponding to 92.55% (w/w) and maximum 96.9%
(v/v), corresponding to 95.16% (w/w) of C2H6O at 20°C. Ethyl alcohol contains minimum 99.5%
(v/v), corresponding to 99.18% (w/w) of C2H6O at 20°C. These values can be seen in the
alcoholometric table (Appendix D).
The centesimal alcoholometer is intended to determine the alcoholic content of mixtures of water and
alcohol, indicating only the concentration of alcohol in volume and expressed by its measurement
unit, degree Gay-Lussac (ºG.L.).
Alcoholmeter determinations are accurate only for the mixture of water and alcohol at 20°C on which
the instrument was graduated. If the temperature during the test is lower or higher than 20°C, it is
necessary to correct the alcohol temperature to 20°C.
The determination of the alcohol degree of water mixtures in volume is carried out by the
alcoholometer.
For the determination of the alcohol degree of the mixtures of water and alcohol in mass, the relative
density method can be used or the graduation in the alcoholometric table can be verified after the
determination by the alcoholometer.
Thermal analysis is a set of methods that enables to measure the physicochemical properties of a
substance according to the temperature. The most commonly used methods are those that measure
the changes in energy or mass of a substance.
THERMOGRAVIMETRY (TG)
Thermogravimetry is the thermal analysis method in which the mass variation of the sample is
determined as a function of temperature, or heating time, using a temperature-controlled program.
Apparatus
It basically consists of a thermobalance that is an association between the electric oven and a high
precision electronic balance, in which the substance is inserted into a sample holder under a specified
atmosphere and a temperature controlled program. The device enables to simultaneously heat and
measure the analyte mass. In certain cases, the device can be associated with a system that makes it
possible to detect and analyze volatile products.
Thermobalance calibration and/or gauging. Transfer an adequate amount of CRS calcium oxalate
monohydrate into the sample holder. The thermobalance will indicate its mass with great precision
and accuracy. Use a heating rate of 10°C/minute and heat the sample to 900°C. At the end of the
thermal process, record: i) the thermogravimetric curve (TG), marking the temperature on the abscissa
axis (increasing values from left to right) and the percentage mass of the sample on the ordinate axis
(increasing values from bottom to top ); ii) the derived thermogravimetric curve (DTG), first derived
from the TG curve, which enables to better define where the loss of mass began and ended. Determine,
on the graph, the distance between the initial and final levels of the mass-temperature curve, the
distance that represents the loss of sample mass in the given temperature range. The reported mass
losses of CRS calcium oxalate monohydrate are calculated stoichiometrically from the three stages
of mass losses due to serial releases of: a) H2O; b) CO; c) CO2. The verification of the temperature
scale can be carried out using the melted metal hook method (In, Pb, Zn, Al, Ag and Au) according
to the manufacturer’s instructions.
Procedure
Use the same method as described for calibration and/or gauging by adding an adequate amount of
sample. The TG and DTG curves, illustrated in Figure 1, indicate a stage of sample mass loss. On
the DTG curve, the initial plateau is between points ab. The loss of mass starts at point b and ends at
point c. The final plateau is between the cd points. Range bc corresponds to the reaction range. To
calculate the sample mass loss on the TG curve, comparison with the DTG curve is used for greater
precision in locating points b and c. Plot the extensions of the initial and final levels of the TG curve
on the ordinate axis using points b and c. The measured distance corresponds to the loss of mass (Dm)
of the sample. The projections of points b and c on the abscissa axis correspond, respectively, to the
initial (Ti) and final (Tf) temperature of the mass loss. Record the result as a percentage of the w/w
ratio.
Note 1: It is necessary to obtain a blank test curve (heating under the same experimental conditions
using the empty sample holder) before testing the sample for baseline subtraction.
Note 2: in case of frequent use of the device, check and/or calibrate regularly. Otherwise, perform
these operations before each determination.
Note 3: As the atmosphere can affect the results, the flow and gas composition are recorded for each
test.
Starting level
(constant mass) Final level
(constant mass)
dm/dt (mg/min)
Mass loss
DTG
Δm
TG
Temperature (ºC)
Uses
The determination of mass variation for a substance at certain temperature ranges can be used to
assess thermal behavior; determination of moisture content and/or solvents; determination of boiling
and sublimation temperature; determination of thermal decomposition temperature and determination
of ash content.
Differential scanning calorimetry is a technique that enables to evaluate the energetic, physical and/or
chemical phenomena produced during the heating (or cooling) of a substance. This method enables
measuring the differential heat flow between the sample and a thermally inert reference material as a
function of temperature and/or heating time under a controlled temperature program. The sample and
reference material are kept at approximately the same temperature during the experiment. The
enthalpy variations can be determined; the changes in specific heat and temperature of endothermic
and exothermic events. According to the measurement method used, there are two modes: DSC with
power compensation and DSC with heat flow.
APPARATUS
The power-compensated DSC consists of a calorimetric cell that contains two ovens, one for the
reference material and the other for the sample. The DSC with heat flow consists of a calorimetric
cell containing a single oven that has a calorimetric sensor for reference and sample. The apparatus
consists of a temperature-controlled programming device, one or more thermal detectors and a
recording system that can be associated with a data processing system. Determinations are carried out
under specified atmosphere.
Equipment calibration and/or gauging. Calibrate the instrument for the temperature and heat flow
axis using high purity indium metal or any other suitable certified material in accordance with the
manufacturer’s instructions. To adjust the linearity, a combination of two metals such as indium and
zinc is used to measure the temperature axis.
PROCEDURE
Transfer a precisely known quantity of the sample to a suitable sample holder. Fix the initial and final
temperature of the test and the heating rate. Start heating. After the test, record the differential
scanning calorimetry curve, writing on the abscissa axis the temperature or time (increasing values
from left to right) and the heat flow on the ordinate axis, indicating the direction (endothermic or
exothermic) . In the DSC curve illustrated in Figure 2, the enthalpic variation between the points acd
is observed. The intersection point b, referring to the extension of the baseline with the tangent at the
point of greatest slope (inflection point) of the curve, corresponds to the onset temperature
(extrapolated start of the event, Tonset), used in melting events such as initial temperature of the change
of state. The end of the thermal event is marked by point c (Tpeak). However, for curve area calculation
purposes, the point d (Tfinal) is considered. The enthalpy variation (ΔH) of the phenomenon is
proportional to the area under the curve limited by the points acd, the proportionality factor being
determined from the determination of the melting enthalpy of a known standard substance (indium,
for example) under the same working conditions. Each thermoanalytical curve is recorded containing
the following data: indication of the last calibration, sample size and identity, type of sample holder,
reference material, atmosphere (flow rate and gas composition), heating rate and sensitivity of the
calorimetric cell.
Heat flow
Endo
Ti Tonset Tpeak Tf
Temperature (ºC)
Uses
The evaluation of the differential heat flow referring to variations in thermal capacity and enthalpy
of the phase transitions of a substance as a function of temperature can be used to determine the
melting point and range; determination of sublimation, evaporation and solidification temperature;
determination of the glass transition temperature; polymorphism evaluation, phase diagram plotting,
purity determination (except for amorphous substances, unstable polymorphs in the experimental
temperature range, compounds that fuse with thermal decomposition and substances with purity lower
than 95%).
Determination of purity
The method is based on the fact that the presence of small amounts of impurities in a given material
lowers its melting point and widens its overall melting range. Figure 3 illustrates this behavior for
three hypothetical samples, one of which is standard and the other two contain small amounts of
impurities.
Heat flow
Endo
Temperature (ºC)
Figure 3 Example of DSC curves of a hypothetical sample with different purity levels.
Based on the van't Hoff equation (Equation 1), it is possible to determine the molar fraction of
impurities X2 (number of moles of impurities by the total number of moles of the sample), considering
that there is no solid phase formation during the melting.
(𝑇0 −𝑇𝑚 )∆
𝑋2 = (Equation 1)
𝑅𝑇02
where Tm represents the melting temperature of the sample; To is the melting point of pure substance
in Kelvin; R is the gas constant (8.3143 J.K-1. mole-1); ΔHf is the melting heat of the main component
expressed in J.mole-1.
When there is no solid phase formation, the concentration of impurity in the liquid phase, at a given
temperature during melting, is inversely proportional to the melted fraction at that temperature, and
the decrease in the melting point is directly proportional to the molar fraction of impurity. The graph
of the sample temperature (Ts) versus the inverse of the molten fraction (1/F), at the temperature Ts,
results in a straight line with a slope equal to the decrease in the melting point (To – Tm). The theoretical
melting point of the pure substance can be obtained by extrapolation when 1/F = 0.
𝑅𝑇02 𝑋2 (1/𝐹)
𝑇𝑆 = 𝑇0 − (Equation 2)
∆𝐻𝑓
By substituting the experimental values obtained for To – Tm, ΔHf and To in equation 1, it is possible
to calculate the molar fraction of the impurities in the sample.
Osmolality is a unit of concentration that refers to the number of osmotically active particles of solute
present in a kilogram of solvent and provides a measure of the contribution of various solutes present
in the solution to the osmotic pressure. An acceptable approximation of the osmolality in aqueous
solution is given by: εm = vmΦ, if the solute is not ionized, v= 1; however v is the total number of
ions always present or formed by the lysis solution of a solute molecule; m = solution molality,
which is the number of moles of solute per kilogram of solvent; Φ = molar osmotic coefficient which
is quantified from the interaction between oppositely charged ions in the solution. It is dependent on
the value of m. If the complexity of the solution increases, F becomes difficult to measure. The
osmolality unit is osmole per kilogram (osmole/kg), but the submultiple milliosmole per kilogram
(mosmole/kg) is normally used.
APPARATUS
The apparatus – Osmometer – consists of: refrigerated container for the measurement; temperature
measurement system equipped with a thermosensor, with a device for measuring different potentials
that can be graduated to decrease the temperature or directly to osmolality; and a feature to
homogenize the solution must be included.
PROCEDURE
Prepare the reference solution as described in Table 1. Adjust device to zero using water. Calibrate
the apparatus using the reference solution: pipet 50 to 250 μL of the sample to be analyzed; transfer
to the measuring cell and start cooling system. Typically, a homogenizing device is programmed to
operate at a temperature below the expected cryoscopic temperature drop to prevent overcooling. A
device indicates when equilibrium is reached. Before each measurement, rinse the measuring cell
with the solution to be tested.
Table 1 – Information for preparing the reference solution for the Osmometer calibration.
Mass in g of sodium
Actual osmolality Ideal osmolality Molal osmotic Cryoscopic
chloride solution per
(mosmole/kg) (mosmole/kg) coefficient decrease (°C)
kg of water
3.087 100 105.67 0.9463 0.186
6.260 200 214.20 0.9337 0.372
9.463 300 323.83 0.9264 0.558
12.684 400 434,07 0.9215 0.744
15.916 500 544.66 0.9180 0.930
19.147 600 655.24 0.9157 1.116
22.380 700 765.86 0.9140 1.302
Carry out the same operation with the test sample. Directly read osmolality or calculate by measuring
congealing point decrease. The test is considered valid when the value found is between two values
on the calibration scale.
Transfer 75 mL of 25% (w/v) potassium hydroxide solution in glycerol to a 1000 mL beaker and heat
to 150°C. Add 50 mL of treated sample as indicated in the specific monograph and continue heating
under agitation. The temperature must not exceed 150°C. Saponification is concluded when the
mixture is homogeneous, without traces of particulate matter. Transfer the mixture to another 1000
mL beaker containing 500 mL of nearly boiling water. Slowly add 50 mL of 25% sulfuric acid
solution (v/v) and heat, with shaking, until the defined separation of the clear phase (fatty acids).
Transfer the fatty phase to a small beaker, wash it with boiling water to free it from sulfuric acid and
keep it in a boiling water bath until the water decants, leaving the oil phase clear. Filter and collect
the fatty acid mixture while still hot in a dry beaker and dry at 150°C for 20 minutes. Transfer the hot
mixture to an appropriate flask and keep it in an ice bath until solidified.
To assess the purity degree of the fatty acids separated by the previous procedure, transfer, prior to
congealing, 3 mL of the desiccated fatty acid solution to a test tube and add 15 mL of ethyl alcohol.
Heat the solution to boil and add 15 mL of 6 M ammonium hydroxide. The resulting preparation must
be clear.
PROCEDURE
The refraction index 𝑛𝑡 of a referred medium to air is equal to the ratio between the sine of the angle
of incidence of a luminous ray in air and the sine of the angle of refraction of the ray refracted in the
considered medium. Unless otherwise indicated, the refractive index is determined at (20 ±0.5) °C
and at a wavelength of 589.3 nm, corresponding to that of sodium D-ray light. In this case, the symbol
representing the refraction index is 𝑛20.
Refractometers usually determine the limit angle. In some devices, the essential part is a prism of
known refractive index, in contact with the liquid under test.
To calibrate the device, use the reference liquids mentioned in Table 1. The refractive index value of
each reference liquid is indicated on its label.
If white light is used to determine the refractive index, the refractometer has a compensation system.
The device must provide accurate readings up to the third decimal place, at least, and have a device
that allows it to operate at the prescribed temperature: the thermometer allows reading to the nearest
0.5 °C minimum.
High acidity indices are suggestive of accentuated hydrolysis of the constituent esters of the fatty
matter. Degradation causes include chemical treatments that are part of industrial extraction and
purification processes, bacterial activity, catalytic action (heat, light), inadequate storage and the
presence of impurities, such as moisture, among others.
PROCEDURE
Weigh approximately 10.0 g or exactly the prescribed amount of test substance and place in a 250
mL Erlenmeyer flask. Add 50 mL of a mixture of 96% (v/v) ethyl alcohol and ethyl ether (1:1). Unless
otherwise indicated in the specific monograph, the solvent mixture must be previously neutralized
with 0.1 M potassium hydroxide, or 0.1 M sodium hydroxide, in the presence of 0.5 mL of
phenolphthalein TS. Heat the sample to 90°C if necessary to dissolve it. After complete solubilization
titrate with 0.1 M potassium hydroxide until a pale pink color persists for minimum 15 seconds. Carry
out the blank test and correct the volume of titrant consumed.
5,610𝑛
𝐼𝐴 =
𝑚
where
The saponification value SV expresses, in milligrams, the amount of potassium hydroxide required to
neutralize the free acids and hydrolyze the esters present in 1 g of the sample.
The IS provides evidence of adulteration of the fatty matter with unsaponifiable substances (mineral
oil, for example). Unless indicated in the specific monograph, use the amount of sample indicated in
Table 1.
Weigh the indicated sample quantity (m), place in a 250 mL volumetric flask and add 25.0 mL of 0.5
M ethanolic potassium hydroxide VS and some boiling stones. Adapt the vertical reflux condenser.
Heat in a water bath for 30 minutes, unless specifically indicated. Add 1 mL of phenolphthalein
solution TS and immediately titrate excess potassium hydroxide with 0.5 M hydrochloric acid
solution VS (n1, mL). Carry out blank assay under the same conditions and correct the titrant volume
(n2, mL).
28,05(𝑛2 − 𝑛1 )
𝐼𝑆 =
𝑚
IE = Is – IA
METHOD A
Unless indicated in the specific monograph, use the amount of sample indicated in Table 1.
In a 250 mL container equipped with a ground stopper, dry or washed with glacial acetic acid,
introduce the sample (m, g) and dissolve it in 15 mL of chloroform, unless otherwise specified in the
respective monograph. Add 25.0 mL of iodine bromide solution. Cap the container and keep it
protected from light for 30 minutes, shaking frequently. After adding 10 mL of 10% potassium iodide
solution (w/v) and 100 mL of water, titrate with 0.1 M sodium thiosulfate VS, shaking vigorously
until the yellow color has almost faded. Add 5 mL of starch TS and proceed with the titration, adding
0.1 M sodium thiosulfate VS, dropwise, and shaking, until the color fades (n1, mL). Blank test must
be carried out under the same conditions and without the sample (n2, mL).
1,269(𝑛2 − 𝑛1 )
𝐼𝑖 =
𝑚
Unless indicated in the specific monograph, use the amount of sample indicated in Table 2.
In a 250 mL container with a ground stopper, previously washed with glacial or dry acetic acid,
introduce the amount of sample (m, g) and dissolve it in 15 mL of a mixture of equal volumes of
cyclohexane and glacial acetic acid, unless stated otherwise. If necessary, pre-melt the sample
(melting point higher than 50°C). Slowly add the volume of iodine chloride solution indicated in
Table 2. Cover the container and shake, protected from light, for 30 minutes, unless otherwise
indicated. Add 10 mL of 10% potassium iodide solution (w/v) and 100 mL of water. Titrate with 0.1
M sodium thiosulfate VS, shaking vigorously until the yellow color almost fades. Add 5 mL of starch
TS and proceed with the titration, adding 0.1 M sodium thiosulfate VS, dropwise, and shaking, until
the color fades (n1, mL of 0.1 M sodium thiosulfate VS). Carry out a blank test under the same
conditions (n2 mL 0.1 M sodium thiosulfate VS). Calculate iodine value according to the following
formula:
1,269(𝑛2 − 𝑛1 )
𝐼𝑖 =
𝑚
If the monograph does not indicate the method to be used, carry out Method A. The replacement of
Method A with Method B is always object of validation.
METHOD A
Weigh 5.00 g of the sample and transfer to a 250 mL Erlenmeyer with a ground stopper. Add 30 mL
of a mixture of glacial acetic acid and chloroform (3:2). Shake until the sample dissolves and add
0.5 mL of saturated potassium iodide solution. Shake for exactly one minute and add 30 mL of water.
Titrate with 0.01 M sodium thiosulfate VS, slowly, without ceasing vigorous agitation, until yellow
color has almost faded. Add 5 mL of starch TS. Continue the titration, shaking vigorously until the
color disappears (n1, mL of 0.01 M sodium thiosulfate VS). Carry out a blank test under the same
conditions n2 mL 0.01 M sodium thiosulfate VS). The blank assay consumes no more than 0.1 mL of
0.01 M sodium thiosulfate VS.
10(𝑛1 − 𝑛2 )
𝐼𝑝 =
𝑚
METHOD B
In an Erlenmeyer flask, with a ground stopper, introduce 50 mL of a mixture of glacial acetic acid
and trimethylpentane (3:2). Add the amount of sample to the Erlenmeyer flask as indicated in Table
1. Cork and shake until the sample dissolves. Add 0.5 mL of saturated potassium iodide solution,
cork again and let the solution stand for (60 ± 1) seconds. During this standing period, shake at least
three times and then add 30 mL of water. Titrate with 0.01 M sodium thiosulfate solution VS (v1, mL),
added slowly, with constant and energetic agitation, until almost total disappearance of the yellow
color characteristic of iodine presence. Add about 0.5 mL of starch TS and proceed with the titration,
without stopping shaking, especially when it is close to the equivalence point, to ensure the release
of iodine from the solvent. Add, drop by drop, the sodium thiosulfate solution until the blue color
starts to fade.
If the peroxide value is equal to or greater than 70, and if there is a delay in the color change of the
starch indicator for 15 to 30 seconds, shake vigorously until the yellow color disappears. This is due
to the tendency of trimethylpentane to supernate in the aqueous phase and the time required to obtain
an adequate mixture between the solvent and the aqueous titrant.
For peroxide numbers less than 150, 0.01 M sodium thiosulfate VS is used. A small amount (0.5 to
1.0% (w/w)) of an appropriate emulsifier may be added to the mixture to delay phase separation and
shorten the time for iodine release (e.g. polysorbate 60). Perform a blank assay (v0, mL). If more than
0.1 mL of 0.01 M sodium thiosulfate VS is consumed, replace the reagents and repeat the titration.
The peroxide value is calculated by the formula below.
1000(𝑣1 − 𝑣0 )𝑐
𝐼𝑝 =
𝑚
where
c = concentration of the sodium thiosulfate solution in moles per liter.
METHOD A
Introduce the sample, accurately weighed, according to the quantity indicated in Table 1, in a 150
mL acetylation flask, unless another volume is specified in the specific monograph. Add the indicated
volume of acetic anhydride solution (acetylation reagent) and fit the reflux condenser.
Heat in a water bath for one hour, taking care to maintain the level of the bath water approximately
2.5 cm above the level of the liquid contained in the flask. Remove the flask and allow to cool. Add
5 mL of water through the top end of the condenser. If the addition of water causes turbidity, add
pyridine until the turbidity disappears and record the volume added. Shake, heat the flask again in a
water bath for 10 minutes. Remove the flask and allow to cool. Wash the condenser and the sides of
the flask with 5 mL of alcohol, previously neutralized in the presence of phenolphthalein TS. Titrate
with an alcoholic solution of 0.5 M potassium hydroxide VS (n1, mL), in the presence of 0.2 mL of
phenolphthalein TS. Carry out a blank test under the same conditions (n2, mL).
28,05(𝑛2 − 𝑛1 )
𝐼𝑂𝐻 = + 𝐼𝐴
𝑚
where
VA = acid value.
METHOD B
In a dry erlenmeyer flask fitted with a ground stopper, introduce the sample solution (m, g). Add
2.0 mL of propionic anhydride, stopper the flask and shake gently, until the sample dissolves. After
two hours of standing, unless otherwise indicated, remove the stopper from the Erlenmeyer flask and
transfer its contents to another 500 mL with a wide mouth, containing 25.0 mL of 0.9% (w/v) aniline
solution in cyclohexane and 30 mL of glacial acetic acid. Shake and, after standing for five minutes,
add 0.05 mL of methylrosanilinium chloride TS. Titrate with 0.1 M perchloric acid VS until turning
to emerald green (n1, mL). Carry out a blank test under the same conditions (n2, mL).
5,610(𝑛1 − 𝑛2 )
𝐼𝑂𝐻 = + 𝐼𝐴
𝑚
where
AV = acid value.
Due to the possibility of water presence, determine the moisture content (y, %) in the sample
according to the specific method. The hydroxyl value is obtained by the formula:
PROCEDURE
Transfer 10 g of substance and 20 mL of acetic anhydride to a 200 mL Kjeldahl flask. Adapt the
reflux condenser. Place the flask on an asbestos mesh in the center of which an orifice of about 4 cm
in diameter has been cut and heat over a gas nozzle with a maximum height of 25 mm (preventing
the flame from reaching the base of the flask). Keep at regular boiling for two hours, cool and transfer
the contents of the flask to a 1000 mL beaker containing 600 mL of water. Add 0.2 g of pumice
powder and boil for 30 minutes. Cool and transfer the mixture to the separating funnel, discarding the
lower aqueous layer. Wash the acetylated substance with three or more 50 mL portions of hot
saturated sodium chloride solution, until the wash solution no longer provides an acidic reaction to
the litmus paper. Add 20 mL of hot water to the funnel and shake, removing the water phase as much
as possible. Transfer to porcelain capsule, add 1 g of powdered anhydrous sodium sulfate and filter
through pleated filter paper. Determine the saponification value of the original, non-acetylation
substance and of the acetylation substance by the procedure described and calculate the acetyl value
using the formula:
(𝑏 − 𝑎) ∙ 1335
𝐼𝐴𝐶 =
1335 − 𝑎
where
If the specific monograph does not indicate the procedure, use Method I. Use glass material with a
ground and degreased mouth.
METHOD I
Add from 2.0 to 2.5 g of the sample in a 250 mL flask. Add 25 mL of 0.5 M ethanolic potassium
hydroxide. Attach a reflux condenser to the flask and boil in a water bath for one hour, under shaking.
Transfer the contents of the flask to a separating funnel, using 50 mL of water and, while the liquid
is still warm, extract, by vigorous shaking, with three 50 mL portions of peroxide-free ether. Wash
the flask with the first ether aliquot. Mix the ethereal solutions in a separating funnel containing 20
mL of water. If the ethereal solutions contain suspended solids, filter into the separating funnel using
a fat-free filter paper. Wash filter with peroxide-free ether. Shake carefully and discard the aqueous
phase. Wash the organic fraction with two 20 mL portions of water and discard the aqueous phase.
Then add three 20 mL portions of 0.5 M potassium hydroxide and shake vigorously for each addition.
After each treatment, washing with 20 mL of water must be carried out. Finally, wash with serial
amounts of 20 mL of water, until the aqueous phase does not show an alkaline reaction in the presence
of phenolphthalein TS. Transfer the organic fraction to a previously tared flask, washing the
separating funnel with peroxide-free ether. Remove the ether and add 3 mL of acetone to the flask.
Eliminate the solvent completely at a constant temperature of maximum 80°C. Dissolve the contents
of the flask in 10 mL of ethyl alcohol 96% (v/v) freshly boiled and previously neutralized. Titrate
with 0.1 M ethanolic sodium hydroxide VS and phenolphthalein TS as indicator. If the volume of
titrant solution spent does not exceed 0.1 mL, the amount of heavy residues should be taken as
unsaponifiable matter. Calculate unsaponifiable matter as a percentage of the substance to be
examined. If the volume of titrant solution spent exceeds 0.1 mL, the amount of heavy residues should
not be taken as unsaponifiable matter and the test must be repeated.
METHOD II
In a 250 mL flask, coupled to a reflux condensation system, introduce the prescribed amount of
sample (m, g). Add 50 mL of alcoholic 2 M potassium hydroxide solution and heat in a water bath
for one hour while shaking. After cooling to a temperature below 25°C, transfer the contents of the
flask to a separatory funnel. Add 100 mL of water. Add 100 mL of peroxide-free ether and shake
carefully. Repeat the operation two more times with 100 mL of ethyl ether. Mix the ethereal solutions
in a separating funnel containing 40 mL of water. Shake gently for a few minutes and let the phases
separate. Discard the aqueous phase. Wash the ether phase twice with 40 mL of water. Then wash
successively with 40 mL of 3% potassium hydroxide (w/v) and 40 mL of water. Repeat this operation
three times. Repeatedly wash the ethereal phase with 40 mL of water, until the aqueous phase does
not provide an alkaline reaction to the phenolphthalein TS. Transfer the ether phase to a previously
tared flask, washing the separating funnel with peroxide-free ether. Evaporate to dryness. Add 6 mL
of acetone to the residue. Carefully remove the solvent in a current of air. Dry at a temperature of
100 °C to 105°C, until mass is constant, allow to cool in a desiccator and weigh (a, g). The result is
calculated as a percentage w/w.
100𝑎
% 𝑑𝑒 𝑖𝑛𝑠𝑎𝑝𝑜𝑛𝑖𝑓𝑖𝑐á𝑣𝑒𝑖𝑠 =
𝑚
Sample solution. Unless indicated in a specific monograph, dissolve approximately 20 mg (one drop)
of the sample, accurately weighed, in 3 mL of methylene chloride.
Standard solution. Dissolve about 20mg (one drop) of corn oil, accurately weighed, in 3mL of
methylene chloride.
Procedure. Separately apply 1 μL of each solution to the plate. Develop twice to a distance of 0.5 cm
with ether. Then develop twice up to a distance of 8 cm with a mixture of methylene chloride, glacial
acetic acid and acetone (2:4:5). Allow the plate to air dry and nebulize with a 10% (w/v)
phosphomolybdic acid solution in alcohol. Heat the plate to 120°C for about three minutes. Examine
in daylight.
1 Peanut Oil 2 Olive Oil 3 Sesame Oil 4 Corn Oil 5 Almond Oil 6 Soybean Oil 7 Sunflower Oil 8 Canola Oil 9 Canola
Oil (Erucic Acid Free) 10 Wheat Germ Oil
Preparation of fatty acid mixture. Heat, under reflux, for 45 minutes, 2 g of the sample with 30 mL
of 0.5 M alcoholic solution of potassium hydroxide. Add 50 mL of water and allow to cool. Transfer
to separation funnel. Shake three times with 50 mL of ethyl ether. Discard ethereal solutions. Acidify
the aqueous phase with hydrochloric acid and shake three times with 50 mL of ethyl ether. Combine
the ethereal solutions and wash three times with 10 mL of water. Discard wash water. Add anhydrous
sodium sulfate to the ethereal fraction and filter. Evaporate at a temperature below 50°C. Use the
residue to prepare the problem solution.
Fatty acids can also be obtained from the saponified solution resulting from the reaction to determine
unsaponifiables.
Sample solution. Dissolve 40mg of the fatty acid mixture obtained from the sample in 4mL of
chloroform.
Standard solution. Dissolve 40mg of the fatty acid mixture, obtained from a mixture of corn oil and
canola oil (19:1), in 4mL of chloroform.
Procedure. Separately apply 3 μL of each solution to the plate. Develop the chromatogram with a
mixture of glacial acetic acid and water (90:10) over a course of 8 cm. Dry the plate at 110°C for 10
minutes. Allow to cool. Place the plate, unless otherwise indicated, in a chromatographic chamber
saturated with iodine vapors. To do this, place iodine in a crystallizer, low, at the bottom of the tank.
After a while, brown or brownish-yellow spots appear. Remove the plate from the tank and wait a
few minutes. When the brown background color of the layer disappears, pulverize with starch TS;
blue stains then appear which, when dry, can turn brown and turn blue again after pulverizing with
water. The chromatogram obtained with the Sample Solution shows spots corresponding to the spots
of the chromatogram obtained with the Standard Solution: one with Rf close to 0.5 (oleic acid) and
another with Rf close to 0.65 (linoleic acid). In certain oils, a spot with Rf close to 0.75 (linolenic
acid) may appear. By comparison with the chromatogram obtained with the Standard solution, verify
the absence of the spot with Rf 0.25 (erucic acid) in the chromatogram obtained with the Sample
solution.
When there is no indication in the specific monograph, use Method A. The search for foreign oils is
carried out on the methyl esters of the fatty acids in the oil under analysis. Proceed as described in
Gas chromatography (5.2.17.5).
METHOD A
This method does not apply to oils containing fatty acid glycerides with epoxy, hydro epoxy,
cyclopropyl or cyclopropenyl groups, or to those containing a large amount of fatty acids with a
carbon chain lower than 8, or to those whose acid values are greater than 2 .0.
Sample solution. If the monograph indicates, dry the sample before starting the assay. Weigh 1.0 g of
the sample and transfer to a 25 mL Erlenmeyer with ground mouth. Couple a reflux condenser and a
device to pass nitrogen stream inside the flask. Add 10 mL of anhydrous methyl alcohol and 0.2 mL
of 6% (w/v) potassium hydroxide solution in methyl alcohol. Pass a stream of nitrogen with a flow
of about 50 mL/minute until the air is eliminated. Shake and heat to boiling. When the preparation is
clear (usually about 10 minutes later), heat it for another five minutes. Cool under running water and
transfer to a separating funnel. Rinse flask with 5 mL of heptane, add to the contents of the separating
funnel and shake. Add 10 mL of 20% sodium chloride solution (w/v) and shake vigorously. Allow
the phases to separate and transfer the organic phase to a flask containing anhydrous sodium sulfate.
Allow to stand and filter.
Standard solution (a). Prepare 0.50 g of a mixture of reference substances as prescribed in the specific
monograph. If the monograph does not indicate the standard solution, use one of those described in
Table 1. Dissolve in heptane, dilute to 50.0 mL with the same solvent and homogenize. Note: For
capillary column chromatography and Split ratio, it is recommended that the long chain component
of the mixture under analysis be added to the calibration mixture when quantitative analysis is
performed by calibration curve.
Standard solution (b). Transfer 1.0 mL of the standard solution (a) to a 10 mL volumetric flask, adjust
the volume with heptane and homogenize.
Standard solution (c). Prepare 0.50 g of a mixture of fatty acid methyl esters as indicated in the analyte
monograph. Dissolve in heptane, dilute to 50 mL with the same solvent in volumetric flask.
Commercial mixtures of fatty acid methyl esters can also be used.
Chromatographic conditions
Column:
Carrier gas flow: 1.3 mL/minute (for 0.32 mm internal diameter columns);
Split ratio: 1:100 or smaller, according to the internal diameter of the column in use (1:50 when the
diameter is 0.32 mm);
Sensitivity: The height of the main peak in the chromatogram obtained with Standard Solution (a) is
50 to 70% of the recorder full scale.
Suitability of the system when mixtures of reference substances are used (Table 2).
Note. For capillary column chromatography and split ratio, it is recommended that the long chain
component of the mixture under analysis be added to the calibration mixture when quantitative
analysis is performed by calibration curve.
- resolution: at least 4 between the peaks of methyl caprylate and methyl caprate, calculated in the
chromatogram obtained with the Standard solution (a);
- signal/noise ratio: at least 5 for the peak referring to methyl caprate, observed in the chromatogram
obtained with the Standard solution (b);
- number of theoretical plates: minimum 15,000, calculated for the peak corresponding to methyl
caproate.
Suitability of the system when mixtures of reference substances are used (Table 1 or Table 3).
Note. For capillary column chromatography and split ratio, it is recommended that the long chain
component of the mixture under analysis be added to the calibration mixture when quantitative
analysis is performed by calibration curve.
- resolution: at least 1.8 between the peaks of methyl oleate and methyl stearate, calculated in the
chromatogram obtained with the Standard solution (a);
- signal/noise ratio: at least 5 for the peak referring to methyl myristate, observed in the
chromatogram obtained with the Standard solution (b);
- number of theoretical plates: minimum 30 000, calculated for the peak corresponding to methyl
stearate.
Chromatogram evaluation. Avoid analysis conditions that allow the emergence of 'masked peaks'
(presence of constituents with close retention times, such as linolenic and arachidonic acids, for
example).
Qualitative analysis
Identify the peaks of the chromatogram obtained with the Standard solution (c) (under isothermal
operating conditions or with linear temperature programming).
When isothermal operating conditions are used, the peaks can be identified by comparison with the
chromatogram obtained with the Standard Solution (a) and information recorded in Table 1, Table
2, or Table 3:
a) measure reduced retention time (t’R) of each peak obtained with the Standard Solution (a). t’R is
the retention time measured in relation to the solvent peak and not in relation to the injection time.
Plot the line through the formula:
b) the logarithms of the reduced retention times of unsaturated acids are points on the straight line,
with non-integer values of carbon atoms called the 'equivalent chain length'. The equivalent chain
length corresponds to the theoretical number of carbon atoms of saturated fatty acids that would have
the same t’R. For example, linoleic acid has t’R s a theoretically saturated fatty acid with 18.8 carbon
atoms. Identify the peaks of the chromatogram obtained with the test solution by calibration curve
and by the reduced retention time. Chain lengths are recorded in Table 4.
Quantitative Analysis
Quantification is generally performed using the normalization method, in which the sum of the areas
under the chromatogram peaks, with the exception of the solvent peak, is assumed to be equal to
100%. Preferably use an electronic integrator.
The percent content of each component is calculated by determining the area under the corresponding
peak versus the sum of the areas under all peaks. Do not consider peaks whose area is inferior to 0.05
percent of the total area.
In certain cases, when the fatty acid chain is inferior or equal to twelve carbon atoms, correction
factors can be indicated in the individual monographs to convert the area under the peaks to a
percentage w/w.
Methyl arachidate 40
Methyl oleate 20
Table 4 – Equivalent chain length (values calculated from calibration curve and analysis with macrogol 20 000
column).
Fatty acid Equivalent chain length
Caproic acid 6.0
Caprylic acid 8.0
Capric acid 10.0
Lauric acid 12.0
Myristic acid 14.0
Palmitic acid 16.0
Palmitoleic acid 16.3
Margaric acid 17.0
Stearic acid 18.0
Oleic acid 18.3
Linoleic acid 18.8
Gamma-linolenic acid 19.0
Alpha-linolenic acid 19.2
Arachidic acid 0.0
Eicosanoic acid 20.2
Arachidonic acid 21.2
Behenic acid 22.0
Erucic acid 22.2
12-oxostearic acid 22.7
Ricinoleic acid 23.9
12-hydroxystearic acid 23.9
Methyl lignocerate 24.0
METHOD B
This method does not apply to oils containing fatty acid glycerides with epoxy, hydro epoxy,
cyclopropyl or cyclopropenyl groups, or to those containing acid values greater than 2 .0.
Sample solution. Add 0.100 g of the sample to a 10 mL centrifuge tube with a ground stopper.
Dissolve with 1 mL of heptane and 1 mL of dimethylcarbonate. Shake vigorously, heating to a mild
heat (50 –60 ºC). Add 1 mL of 1.2% (w/v) sodium solution in anhydrous methyl alcohol to the still
hot solution. Shake vigorously for about five minutes. Add 3 mL of distilled water and shake
vigorously for about 30 seconds. Centrifuge for 15 minutes at 1500 g. Inject 1µL of the organic phase.
Standard solutions and evaluation of chromatograms. In the absence of specific indication in the
individual monograph, proceed as described in Method A.
– column of fused silica 30 m in length and 0.25 mm in internal diameter, covered withmacrogol 20
000 (film thickness: 0.25 μm);
– carrier gas: helium for chromatography, with a flow of 0.9 mL/minute;
– flame ionization detector;
– Split ratio 1:100
METHOD C
This method does not apply to oils containing fatty acid glycerides with epoxy, hydroperoxy,
aldehyde, ketone, cyclopropyl and cyclopropenyl groups, as well as oils with conjugated
polyunsaturated groups or with acetylenic groups due to the partial or total destruction of these
groups.
Sample solution. In a 25 mL conical flask, dissolve 0.10 g of the sample in 2 mL of a 2% (w/v) sodium
hydroxide solution in methyl alcohol. Fit the flask to the vertical reflux condenser and heat for 30
minutes. Through the condenser, add 2.0 mL of boron trifluoride-methanol solution and heat for 30
minutes. Through the condenser, add 4 mL of heptane and heat for five minutes. Cool the mixture
and add 10.0 mL of saturated sodium chloride solution. Shake for 15 seconds and add enough
saturated sodium chloride solution to bring the upper phase to the neck of the container vial. Remove
a 2 mL aliquot from the upper phase. Wash three times with 2 mL of water and dry with anhydrous
sodium sulfate.
Prepare the unsaponifiable fraction. Separate the sterol fraction from the fixed oil by thin-layer
chromatography, using a silica-gel G plate (layer thickness between 0.3 mm and 0.5 mm).
Sample solution (a): In a 150 mL flask, add a volume of 0.2% (w/v) betulin solution in methylene
chloride, which corresponds to approximately 10% of the sterol content of the sample used for the
assay (for example, volume of 500 μL of betulin solution for virgin olive oil, and 1500 μL for other
vegetable oils). If the monograph requires to calculate the percentage content of each sterol in the
sterol fraction, the addition of betulin may be omitted. Evaporate to dryness in nitrogen stream. Add
5.00 g of the sample and 50 mL of 2M potassium hydroxide in ethyl alcohol. Couple the vertical
reflux condenser. Heat in water bath for one hour, under agitation. Cool to a temperature below 25°C
and transfer the contents of the flask to a separating funnel, using 100 mL of water. Carefully shake
three times with 100 mL of peroxide-free ethyl ether. Mix the ethereal solutions in a separating funnel
containing 40 mL of distilled water. Shake gently for a few minutes. Allow the phases to be separated
by decantation and discard the aqueous phase. Wash the organic phase several times with 40 mL of
water, until the aqueous phase does not show an alkaline reaction to phenolphthalein TS. Transfer the
organic fraction to a previously tared flask, washing the separating funnel with ethyl ether. Evaporate
the ether. Add 6 mL of acetone to the residue. Carefully remove the solvent with a stream of nitrogen.
Dry in oven at 100 – 105 °C until constant mass. Dissolve the residue with minimal volume of
methylene chloride.
Sample solution (b): Submit 5.00 g of canola oil to the same procedure described for Sample Solution
(a) from “Add 50 mL of 2 M potassium hydroxide in ethyl alcohol...”.
Sample solution (c): Submit 5.00 g of sunflower oil to the same procedure described for Sample
Solution (a) from “Add 50 mL of 2 M potassium hydroxide in ethyl alcohol...”.
Standard solution. Dissolve 25mg cholesterol and 10 mg betulin in 1mL methylene chloride. Use a
different plate for each problem solution.
Separately apply to the plate 20 μL of the Standard Solution in a band of 20 mm by 3 mm and 0.4 mL
of the problem solution (a), (b) or (c) in a band of 40 mm by 3 mm. Migrate over a distance of 18 cm
with the mobile phase, consisting of a mixture of ether and n-hexane (35:65). Dry the plates in a
stream of nitrogen. Develop with a 0.2% (w/v) dichlorofluorescein solution in ethyl alcohol. Examine
in a UV lamp at 254 nm.
The chromatogram obtained with the Standard Solution shows bands corresponding, respectively, to
cholesterol and betulin. The chromatograms obtained with the Sample solutions show Rf bands close
to those corresponding to the sterols. From each of the chromatograms, scrape the region of the plate
corresponding to the sterol bands, as well as an area located 2 – 3 mm above and below the visible
areas corresponding to the standard solution. Place these regions in three different 50 mL Erlenmeyer
flasks. Add 15 mL of hot methylene chloride to each and shake. Filter each solution separately on a
porous glass filter (40) or on a suitable filter paper. Wash each filter three times with 15 mL of
methylene chloride. Transfer the filtrate and washing liquids in a tared Erlenmeyer flask. Evaporate
to dryness in nitrogen stream, then weigh.
STEROL ASSAY
Proceed as described in Gas chromatography (5.2.17.5). The assay must be carried out in a place with
low moisture content and solutions prepared at the time of use.
Sample solution. To the sterols separated from the sample by thin layer chromatography, add 0.02
mL of fresh-prepared mixture of chlorotrimethylsilane, hexamethyldisilazane and anhydrous pyridine
(1:3:9) per milligram of residue. Shake carefully until the sterols are fully dissolved. Allow to stand
in a desiccator with phosphorus pentoxide for 30 minutes. Centrifuge if necessary and use the
supernatant.
Standard solution (a). To nine parts of the sterols separated from the canola oil by thin layer
chromatography, add one part of cholesterol. Add 0.02 mL of fresh-prepared mixture of
chlorotrimethylsilane, hexamethyldisilazane and anhydrous pyridine (1:3:9) per milligram of residue.
Shake carefully until the sterols are fully dissolved. Allow to stand in a desiccator with phosphorus
pentoxide for 30 minutes. Centrifuge if necessary and use the supernatant.
Standard solution (b). To the sterols separated from the sunflower by thin layer chromatography, add
0.02mL of freshly prepared mixture of chlorotrimethylsilane, hexamethyldisilazane and anhydrous
pyridine (1:3:9) per milligram of residue. Shake carefully until the sterols are fully dissolved. Allow
to stand in a desiccator with phosphorus pentoxide for 30 minutes. Centrifuge if necessary and use
the supernatant.
Chromatographic conditions
- column of fused silica 20 to 30 m in length and 0.25-0.32 mm in internal diameter, covered with
a film of poly[methyl(95) phenyl(5)] siloxane or poly[methyl(94) phenyl( 5) vinyl(l)] siloxane
(0.25 µm film thickness);
- carrier gas: hydrogen gas with a linear velocity from 30 to 50 cm/s or helium with a linear velocity
from 20 to 35 cm/s;
- Split ratio (1/50 or 1/100);
- temperatures: column: 260 °C; injector 280 °C; detector: 290°C
- Injection volume: 1 μL.
Results. The chromatogram obtained with the Standard solution (a) presents four main peaks,
corresponding, respectively, to cholesterol, brassicasterol, campesterol and β-sitosterol. The
chromatogram obtained with the Standard solution (b) presents four main peaks, corresponding,
respectively, to campesterol, stigmasterol, β-sitosterol and Δ7-stigmasterol. The relative retention
times of the different sterols in relation to β-sitosterol are shown in Table 1.
The peak corresponding to the internal standard (betulin) is sharply separated from the peaks
corresponding to the sterols to be quantified.
Table 1 – Relative retention times of sterols in relation to β-sitosterol obtained with two different columns.
Poly[methyl(95)phenyl(5) Poly[methyl(94)phenyl(5)vinil(1)
Sterols
siloxane siloxane
Cholesterol 0.63 0.67
Brassicasterol 0.71 0.73
24-Methylenecholesterol 0.80 0.82
Campesterol 0.81 0.83
Examine the Sample solution chromatogram. Identify the peaks and calculate the percentage content
of each sterol in the sterol fraction using the formula:
𝐴
× 100
𝑆
where
If there is a requirement in the monograph, calculate the content of each sterol in the sample, in
milligrams per 100 grams, using the expression:
𝐴 × 𝑚𝑠 × 100
𝐴𝑠 × 𝑚
where
The methods generally rely on the complete oxidation of organic molecules to carbon dioxide, which
is quantified as carbon. Normally, organic carbon is oxidized by combustion, applying heat,
ultraviolet emission, or oxidizing agents such as sodium persulfate. Quantification of carbon dioxide
is done by detecting the gas produced with infrared or by reading the solution conductivity.
The method covered in this chapter is only a suggestion and the user can adopt any one that is
appropriate and accessible for his specific purposes, as long as the quantification limit is adequate for
the expected reading range. The method uses a standard solution of easily oxidizable substance, such
as sucrose, for example, in such a concentration that the obtained instrumental response corresponds
to the established limit for the TOC. The method may also be carried out with an apparatus installed
on-line, which has been properly calibrated and which satisfies the system compliance test.
Table 1 shows the average expected values for the main types of water purification.
APPARATUS
It consists of an injector, a device to decompose the sample, a system to separate the formed carbon
dioxide, a detector and a recorder of the emitted electrical signal. The decomposition tube must be
capable of generating minimum 0.450mg/L of organic carbon for a sample of 1.071mg/L of sucrose.
The detection limit of the apparatus, specified by the manufacturer, is equal to or less than 0.050 mg
of carbon per liter (0.05 ppm). System compliance is periodically checked using a solution prepared
with a substance that is difficult to oxidize, such as 1.4-benzoquinone. The location of the apparatus
is chosen to ensure that the results obtained are representative of the water used. The reading must be
taken immediately after collecting the water sample.
Depending on the type of apparatus used, heavy metal and copper contents can be critical. Observe
the manufacturer’s instructions.
Use COT water as blank; in the preparation of standard solutions; system suitability solution and
equipment cleaning. The preparation of the standard solution and the system compliance solution
must be concurrent with the sample.
Carefully wash the glass material using a process that eliminates organic matter. Place the material
immersed in a mixture of equal parts of a 30% diluted hydrogen peroxide solution and diluted nitric
acid. Rinse with TOC water.
If a micro syringe is used to inject the sample, it should be washed with a mixture of 5% sodium
hydroxide solution (w/v) and absolute ethyl alcohol (1:1), or in 25% hydrochloric acid. Rinse
thoroughly with TOC water.
PREPARATION OF SOLUTIONS
Blank. Prepare blank solution, or any other solutions required to set the baseline, or proceed with
calibration, as per the manufacturer’s instructions. Use the appropriate blank to zero the device.
Standard solution. Dissolve sucrose mass, previously dried at a temperature of 105 °C for three hours,
in TOC water, in order to obtain a solution containing 1.19 mg of sucrose per liter of solution (0.50
mg of carbon per liter), to check the instrument.
Use a potassium acid phthalate solution in COT water, previously dried at 105°C for four hours, at
the concentration determined by the equipment manufacturer, for instrument calibration. Preserve the
solution by acidifying with concentrated phosphoric acid or concentrated sulfuric acid at pH < 2. To
determine organic and inorganic carbon, separately, also prepare a standard solution of sodium
bicarbonate (dried in a desiccator for not less than 18 hours) and decayed sodium carbonate (dried at
500 – 600 °C for 30 minutes) at 1:1 carbon content ratio in TOC water.
The concentration of the standard solution was calculated for purified water, whose TOC limit is
500 ppb. For other types of water, adjust accordingly.
System compliance solution. Dissolve 1,4-benzoquinone in TOC water to obtain a solution of 0.75mg
of 1,4-benzoquinone per liter (0.50mg of carbon per liter).
Sample. Collect the water sample in a clean, dry container with a lid, leaving a minimum of air. Take
care not to have any kind of contamination. Do not use plastic material. Carry out the analysis as soon
as possible to minimize the risk of deterioration or contamination of the sample.
SYSTEM COMPLIANCE
Proceed with the readings (L) of the COT water solutions (Ltoc), standard solution (LPa), system
compliance solution (LCS) and record. Calculate the efficiency of the system in percentage, using the
expression:
𝐿𝑐𝑠 − 𝐿𝑐𝑜𝑡
× 100
𝐿𝑝𝑎 − 𝐿𝑐𝑜𝑡
The system will be in compliance if the obtained value is between 85% and 115% of the theoretical
response.
PROCEDURE
Use the analytical method recommended by the manufacturer of the equipment used. Inject an
adequate volume of the sample and read the total carbon.
Determine the sample reading (LAm). The sample complies with the test if LAm is not greater than
LPa – LToc.
For different calculations of the organic and inorganic carbon fractions, read the total organic carbon,
change the apparatus configuration to the inorganic carbon reading and calculate the organic carbon
by subtraction. Alternatively, one can measure organic carbon after removing the inorganic carbon
and subtracting the total carbon. Normally, for high purity waters the inorganic carbon fraction is
negligible.
The DRXP method is non-destructive in nature (sample preparation is generally limited to milling to
reduce the particle size to around 5 µm). Investigations using DRXP can also be carried out under in
situ conditions on specimens exposed to non-environmental conditions, such as low or high
temperature and humidity.
Each crystalline phase of a given substance produces a characteristic X-ray diffraction pattern, which
is obtained from a crystalline powder, composed of crystallites or crystalline fragments of
characteristic size and randomly oriented. Essentially three types of information can be obtained with
a DRXP pattern: angular position of the diffraction lines (depending on the dimensions of the unit
cell and its geometric crystallographic arrangement); intensity of diffraction lines (depending mainly
on the type and arrangement of atoms, and the orientation of particles within the sample) and
diffraction line profiles (depending on the instrumental resolution, crystallite size and micro strain of
the sample).
DRXP tests that provide the angular positions and line intensities of the crystalline phases are used
for phase identification, determination of grades, estimate of crystallinity degree, micro deformation
and average crystallite size.
PRINCIPLE
Every crystalline material has an organization of atoms that defines a unit cell. The unit cell is defined
by the dimensions𝑎, 𝑏 and 𝑐 and the angles between them,𝛼, 𝛽 e 𝛾 (Figure 1a). Interplanar spacing
for a set of parallel planes ℎ𝑘𝑙 is represented by 𝑑ℎ𝑘𝑙. Each set of crystal planes has a Bragg diffraction
angle, 𝜃ℎ𝑘𝑙, associated with it (for a specific wavelength 𝜆).
X-ray diffraction results from the interaction between X-rays and the electron clouds of atoms.
Depending on the atomic arrangement, scattered X-rays exhibit the phenomenon of constructive
interference, when the path difference between two diffracted X-ray waves is equal to an integer
number of wavelengths. This selective condition is described by the Bragg equation (Equation 1),
also called Bragg's Law represented in Figure 1b.
where
A powder sample is considered polycrystalline if, for any angle 𝜃ℎ𝑘𝑙 , there are always crystallites in
one orientation, allowing diffraction according to Bragg's law. For a given wavelength of X-rays, the
positions of the diffraction peaks (also referred to as 'lines', 'reflections' or 'Bragg reflections') are
characteristic of the crystal structure (d spacings). The main characteristics of the diffraction line
profiles are the 2𝜃position, height, area and shape of the peak (characterized, for example, by peak
width or asymmetry, analytical function, empirical representation). Figure 2 represents an example
of the type of powder X-ray diffraction patterns obtained for five different solid phases of the same
substance.
Form D
Form C
Form B
Form A
Amorphous
2Ɵ(λCu)-Scale
Figure 2 - Examples of X-ray powder diffraction patterns collected for
five different solid phases of a substance.
In addition to the diffraction peaks, an X-ray diffraction experiment also generates a baseline, over
which the peaks overlap. Factors contributing to the baseline are air diffuse scattering, apparatus and
the presence of amorphous (Figure 2). The ratio of peak intensities to baseline can be increased by
minimizing the baseline and choosing longer exposure times.
APPARATUS
X-ray diffraction experiments are usually performed using powder diffractometers. A powder
diffractometer generally consists of five main parts: an X-ray source; incident beam optics (set of slits
for collimation and beam focusing); sample port; diffracted beam optics (set of slits for collimation,
beam focusing and convenient filter for radiation) and a detector. Data collection and processing
systems are also required and comprise the X-ray diffraction measurement device. Currently, the
Bragg-Brentano configuration is the most commonly used.
A given instrument can provide either a horizontal or vertical 𝜃/2𝜃 geometry or a vertical geometry
𝜃/𝜃. For both geometries, the X-ray beam is incident at an angle 𝜃 with the surface plane of the
sample and the diffracted X-ray beam forms an angle 2𝜃 with the direction of the incident X-ray
beam (an angle𝜃 with the sample surface plane). The basic diffraction geometry is shown in Figure
3. The divergent radiation beam from the X-ray tube (the so-called 'primary beam') passes through
the parallel plate collimators, a divergence slit and illuminates the flat surface of the sample. All rays
diffracted by the crystallites properly oriented in the sample at an angle of 2𝜃 converge to a receiving
slit. A second set of parallel plate collimators and a scattering slit can be placed behind or before the
receiving slit. The axes of the focus of the X-ray source and the receiving slit are at equal distances
from the axis of the goniometer. X-ray quanta are counted by a radiation detector, usually a
scintillation counter, a gas-sealed proportional counter or a position-sensitive solid-state detector such
as an image plate or a CCD detector. The receiving slit and detector are coupled and move tangentially
to the focus circle. For 𝜃/2𝜃 sweeps the goniometer rotates the sample about the same axis as the
detector, but at half the rotation speed, in a 𝜃/2𝜃 motion. Thus, the sample surface remains tangential
to the focus circle. The parallel plate collimator limits the axial divergence of the beam and therefore
partially controls the shape of the diffracted line profile.
A diffractometer can also be used in transmission mode. The advantage with this technology is the
effects reduction due to the preferential orientation. A capillary about 0.5 to 2 mm thick can also be
used for small amounts of sample.
A – X-ray tube; B – Divergence slit; C - Sample; D – Anti-scatter slit; E – Receiving slit; F – Monochromator; G –
Detector receiving slit; H – Detector; J – Diffractometer circle; K – Focusing circle.
X-RAY RADIATION
In the laboratory, X-rays are obtained by bombarding a metal anode with electrons emitted by the
thermoionic effect and accelerated in a strong electric field (using a high-voltage generator). Most of
the kinetic energy of the electrons is converted into heat, which limits the power of the X-ray tubes
and requires anode efficient cooling. A 20- to 30-fold increase in brightness can be obtained using
rotating anodes and through X-ray optics. Alternatively, X-ray photons can be produced in a large-
scale installation (synchrotron).
The spectrum emitted by an X-ray tube operating with sufficient voltage consists of a continuous
background of polychromatic radiation and additional characteristic radiation that depends on the
type of anode. Only this characteristic radiation is used in X-ray diffraction experiments. The main
radiation sources used for X-ray diffraction are vacuum tubes, using copper, molybdenum, iron,
cobalt or chromium as anodes; X-rays produced by copper (𝐶𝑢𝐾𝛼), molybdenum or cobalt are most
commonly used for organic substances (the use of cobalt anodes may be especially preferred to
separate different X-ray lines). The choice of radiation to be used depends on the absorption
characteristics of the sample and the potential fluorescence caused by atoms present in the sample.
The wavelengths used in diffraction generally correspond to the radiation 𝐾𝛼 from the anode.
Consequently, it is advantageous to make the X-ray beam 'monochromatic', eliminating all other
components of the emission spectrum. This can be achieved in part using𝐾𝛽 filters, i.e. metallic filters
selected as having an
absorption discontinuity between the wavelengths 𝐾𝛼 and 𝐾𝛽 emitted by the tube. The filter is usually
inserted between the X-ray tube and the sample. Another method often used to obtain a
monochromatic X-ray beam is by means of a monochromator crystal. This crystal can be placed in
the incident beam, obtaining a pure monochromatization Kα1, or after the sample, obtaining Kα1,2 at
different angles, so that only one of them can be selected to focus on the detector.
RADIATION PROTECTION
Exposure of any part of the human body to X-rays can be harmful to health. Therefore, it is essential
that proper precautions are taken to protect the operator and anyone else in the vicinity of X-ray
equipment in use.
SAMPLE PREPARATION
The pulverized sample is often pressed into a sample holder made of aluminum, glass or polymer. As
a rule, crystallites must be randomly oriented. The samples must be ground in an agate mortar to a
fine powder.
In general, the morphology of many crystalline particles tends to generate a sample that has some
degree of preferential orientation in the sample holder. This is particularly evident for needle or plate-
shaped crystals when reducing the size of the crystals produces smaller needles or plates. The
preferred orientation of the sample influences the intensities of various reflections. Thus, some are
more intense whereas others less, compared to what would be expected in a sample with completely
random crystallites. Various methods can be employed to minimize the randomness in crystallite
orientation (and therefore to minimize the preferred orientation), but particle size reduction is often
the best and simplest. In some cases, particle sizes of 10 µm will provide satisfactory results in phase
identification. However, reducing this particle size may be convenient if no phase changes or
amorphization of the material occur. Therefore, it is advisable to compare the diffraction pattern of
the unground sample with that corresponding to a sample of smaller particle size (ground sample).
The goniometer and optical system corresponding to the incident and diffracted X-ray beams have
many mechanical parts that need adjustment. The degree of alignment or misalignment directly
influences the quality of the results of a DRXP investigation. Therefore, the different components of
the diffractometer must be carefully adjusted (optical systems and mechanisms, etc.) to minimize
systematic errors, optimizing the intensities received by the detector. The pursuit of maximum
intensity and maximum resolution are always antagonistic when aligning a diffractometer.
Accordingly, the best equilibrium must be sought while performing the alignment procedure. Each
device has its own configuration and requires a specific alignment procedure.
The overall performance of the diffractometer should be periodically tested and monitored using
properly certified reference materials. Depending on the type of analysis, other well-defined reference
materials may also be employed, although the use of certified reference materials is preferred.
The identification, by XRPD, of the phases that constitute an unknown sample is based on a visual or
computer-aided comparison with the peaks of a reference chemical substance, well characterized or
calculated, from the crystal structure model or from certified databases. Ideally, these diffraction
patterns are obtained on well-characterized single-phase specimens. This approach makes it possible,
in most cases, to identify a crystalline substance through the spacings 𝑑 and their relative intensities.
The list of spacing 𝑑 and normalized intensities𝐼𝑛𝑜𝑟𝑚 , also called list (𝑑, 𝐼𝑛𝑜𝑟𝑚) extracted from the
pattern, is the crystallographic fingerprint of the material and can be compared with the lists(𝑑, 𝐼𝑛𝑜𝑟𝑚)
of single-phase reference samples.
For most organic crystals, when 𝐶𝑢𝐾𝛼 radiation is used, it is useful to record the diffraction pattern
in a 2𝜃 range of 2°to not less than50°. The variation of the 2𝜃 diffraction angles between sample
and reference must be lower than 0,2°for the same crystal form, while the relative intensities between
sample and reference can vary considerably due to preferential orientation effects. By their very
nature, hydrates and solvates are recognized to have variations in unit cell dimensions, so changes
can occur in the peak positions of the DRXP standards measured for these materials. In these cases,
variation of 2𝜃 positions higher than0,2° are expected.
It is sometimes difficult or even impossible to identify phases in the following cases: amorphous or
non-crystallized substances; when the components to be identified are in low concentration; when the
phase is not present in certified databases or does not have a determined crystal structure; or when
the sample comprises many phases.
If the sample under investigation is a mixture of two or more known phases, of which no more than
one is amorphous, the percentage (by volume or mass) of each crystalline phase and the amorphous
phase can, in many cases, be determined. Quantitative phase analysis can be based on integrated
intensities, on the heights of several individual diffraction lines, or on the complete pattern. These
integrated intensities; heights or data from complete standards are compared with corresponding
values from reference materials. These reference materials must be single-phase or a known mixture
of phases. Difficulties encountered during quantitative analysis are due to sample preparation (the
accuracy and precision of the results require special homogeneity of all phases and an adequate
particle size distribution in each phase) and matrix effects. If crystal structures of all components are
known, the Rietveld method can be used to quantify them with acceptable precision. In favorable
cases, amounts of crystalline phases as small as 10% in solid matrices can be determined.
Nuclear magnetic resonance (NMR) spectroscopy is an analytical procedure that is based on the
magnetic properties of certain atomic nuclei. It is similar to other spectroscopic methods in which
energy is absorbed and emitted at a certain frequency, providing analytical information. NMR differs
from other methods as it creates discrete levels of energy between the transitions of the nucleus of
atoms in a molecule when subjected to a magnetic field.
Atomic nuclei, when magnetically charged, rotate about the nuclear axis, creating a magnetic dipole
moment (µ) along this axis. Those that exhibit this behavior are called isotopes. The angular
momentum of this nuclear spin is characterized by the nuclear spin quantum number (I). If the mass
number is odd, the value of I is ½ or an integer plus ½; otherwise, it has a value of zero or an integer.
When nuclei have a non-zero spin quantum number (I ≠ 0) and are subject to a static and uniform
external magnetic field of force (H0), they align with the respective field with (2I + 1) possible
orientations. However, for nuclei with I = ½, there will be two possible orientations, which
correspond to two different energy states. Thus, a nuclear resonance is the transition between these
spin states, caused by the absorption and emission of the corresponding amount of energy. In Table
1 spin quantum numbers of some nuclei are presented.
In a static magnetic field, the nuclear magnetic axis undergoes a precession movement (Lamor
precession) around the axis of the external field. The precession angular velocity (ωo) is related to the
strength of the magnetic field through the formula ωo = γH0; where γ is the gyromagnetic constant
and is intrinsic to all nuclei of a given isotope. With the introduction of oscillating radiofrequency
energy, the absorption of radiation by the paramagnetic core takes place according to the formula:
ΔE = hυ = µH0/I
Therefore, when frequency (υo) of external energy field (E = hυ) is the same as the precession
angular velocity, resonance occurs.
The difference in energy between the two levels corresponds to a specific electromagnetic radiation
within the range of radio frequencies used. This is a function of γ, which is a property of the nucleus,
and Ho which represents the strength of the external field. The resonant frequency of a nucleus rises
when the strength of the magnetic field increases.
The signal characteristics in the spectra that provide analytical information are: chemical shift,
multiplicity, peak width, coupling constant and relative intensity.
NMR spectroscopy has a wide range of applications, such as structure elucidation; thermodynamic
studies; kinetics, mechanics and in quantitative analysis.
APPARATUS
Currently, the most used spectrometer is the Fourier transform. The main components of an NMR
spectrometer are: magnet to provide a constant magnetic field (B0); temperature-controlled probe that
receives the sample; conducts the radio frequency pulse and detects the radiation emitted by the
sample; and electronic console (computer) for generating high energy radiofrequency pulses,
collecting and digitizing the induced free decay signal (FID – free induction decay).
The devices use a single pulse of radio frequency energy to simultaneously excite all the nuclei. The
excited nuclei return to the lowest energy level, generating an accumulation of FID signals at a given
time. The decay time and frequency form a Fourier transform, generating a graph of amplitude versus
frequency (spectrum). After the time in which the excited nuclei relax is possible, the pulse can be
repeated and thus the response obtained accumulates in the computer memory, promoting greater
resolution.
Figure 1 shows the instrumental parts constituting a high-resolution pulse spectrometer (NMR).
Computer
Probe Accumulation
Spectrum
Conversor
Receptor
Exposure to magnetic fields and radio waves can be harmful to health. Thus, it is essential that proper
precautions must be taken to protect the operator and anyone else in the vicinity of NMR equipment
in use.
SPECTRUM
Peaks in an NMR spectrum are characterized by: frequency, multiplicity and relative intensity. The
analytical utility of the NMR method lies in the fact that the same nuclei, when found in different
molecular environments, show different resonance frequencies. The reason for this difference is that
the electromagnetic field experienced by a particular nucleus is composed of an external field
provided by the instrument and the field generated by the circulation of its electrons. The latter
opposes the external field and the coupling phenomenon. Thus, it is possible to accurately measure
the frequency difference between the resonant signals (peaks). The position of a signal in a NMR
spectrum is described by its separation from another resonant signal taken as a reference. This
separation is called chemical shift.
The chemical shift is directly proportional to the strength of the magnetic field (the frequency of the
radio frequency emitter). However, the ratio of chemical shift (in frequency units) to instrument
frequency is constant. This enables the definition of a dimensionless chemical shift parameter (δ) that
is independent of the instrument frequency:
δ = (υs – υr)/υp + δr
where
υs = frequency of the substance being analyzed;
υr = reference frequency;
υp = equipment frequency (in MHz);
δr = chemical shift from the reference.
The formula above is applicable to nearly all methods, with few exceptions. Tetramethylsilane (TMS)
is the chemical shift reference most used to obtain hydrogen and carbon spectra since it is chemically
inert, has a single signal at a higher field than most signals, and is volatile, enabling rapid sample
recovery. Using the formula, it is possible to use the chemical shift of any species known as the
chemical reference shift, for example, deuterated solvents that contain 1H residue. Some care is
necessary when TMS is not used as a solvent.
In NMR spectra, the strength of the magnetic field increases from left to right. Nuclei that resonate
under high magnetic field strengths (to the right) are better protected (higher electronic density) than
those that resonate under lower magnetic field strengths.
In Figure 2, the hydrogen NMR spectrum of benzoyl acetate is shown. This substance contains
hydrogens in methyl, methylene and aromatic groups. These groups are located in distinct molecular
environments, observed in the spectrum as three different hydrogen peaks referring to methyl (CH3),
methylene (CH 2), in addition to the peak corresponding to the resonance of aromatic hydrogens (H-
Ar) (a, b and c, respectively).
Another information to be obtained in the NMR spectrum is the phenomenon of the spin-spin
interaction. Accordingly, the coupling between the nuclei, called spin-spin coupling (J), corresponds
to the separation (in Hertz) between the individual peaks of the signal (multiplet). When the
interaction of the nuclei occurs in a reciprocal manner, the coupling constants observed in the
multiplets are equal. In addition, J is independent of the magnetic field strength.
In a relatively simple first-order spin system, the number of individual peaks expected in a multiplet
and the relative peak intensities are predictable. The number of peaks is determined by 2n + 1 (only
when J is equal), where n is the number of nuclei in adjacent groups that share the same signal. For
hydrogen it is convenient (n + 1) peaks. In general, relative intensity of each peak is the multiplet
signal followed by the binomial expansion coefficient (a + b)n. These coefficients can be found using
Pascal's triangle, which produces the following relative areas for the related signals: doublet (1:1),
triplet (1:2:1), quartet (1:3:3:1), quintet (1:4:6:4:1), sextet (1:5:10:10:5:1), and heptet
(1:6:15:20:15:6:1). This ordered system, usually Dv referred to a first-order behavior, can be expected
when the ratio and J is higher than 10; Dv is the chemical shift difference between the nuclei and the
equivalent nuclei groups. Two examples of first-order coupled spectra are shown in Figure 3.
In Figure 4, a spectrum with triplet and quartet signals is presented. We can note that the methylene
hydrogens are split into a quartet (four peaks) and that the methyl group is split into a triplet (three
peaks).
Relative intensity is another feature of the experiment that has wide analytical applications. The area
of a signal is directly proportional to the number of hydrogens present in a spectrum.
As a result, it is possible to determine the relative ratio of different types of hydrogens, or other nuclei,
in a sample.
The NMR spectrum may contain signals unrelated to the sample due to the inhomogeneity of the
magnetic field. These signals, called high rotation sidebands, indicate that it is necessary to adjust the
compensation coils and are easily identifiable. The separation of the signals is equal to the frequency
of the rotation speed of the sample tube.
METHOD
Sample preparation or incorrect instrumental settings and parameters can lead to decreased sensitivity
(low resolution), spectral artifacts, and erroneous data. The user must be familiar with NMR theory,
sample properties, and instrument operating principles. The instruction manuals provided by the
manufacturers must be strictly followed and frequent checks on the equipment calibration and
operation must be carried out.
The procedures described herein refer specifically to hydrogen (1H NMR) and fluorine (19F NMR)
NMR, and can be applied, with some modifications, to other nuclei. The NMR spectrum is obtained
from liquid or solid samples dissolved in an appropriate solvent.
Solvent selection – Appropriate solvents, in addition to having good dissolving properties, should not
present resonance peaks that interfere with those originated by the sample under analysis. The most
used solvents in hydrogen and carbon NMR are described in Table 2. Deuterated solvents also
provide their signals to heteronuclear systems, enabling field fixation. The isotopic purity of the
solvent should be as high as possible to avoid peaks of these impurities making it difficult to see any
signal from the sample. Deuterium (J = 1) does not resonate under 1H conditions, but can cause J
coupling.
Table 2 – Chemical shift values of 1H (ppm) for some solvents commonly used in NMR.
Solvent Deuterated form Chemical Shift (Multiplicity)
Acetone Acetone-d6 2.05 – 5
Acetonitrile Acetonitrile-d3 1.93 – 5
Benzene Benzene-d6 7.15 (wide)
Carbon tetrachloride ---- ----
Chloroform Chloroform-d 7.25 – 1
Dimethylsulfoxide Dimethylsulfoxide-d6 2.49 – 5
Water Deuterium oxide 4.82 – 1
Methanol Metanol-d6 4.84 (1) hydroxyl
3.30 (5) methyl
Methylene chloride Methylene chloride-d2 5.32 – 3
In some solvents (D2O and CD3OD), rapid exchanges of deuterium with the hydrogen in the sample
can occur, eliminating the signal of a series of groups: -COOH, -OH and -NH2. The hydrogens of
alcohols and amines are not exchanged quickly, except in the presence of D2O and some other
solvents (CD3OD), and can be restored with small concentrations of acid or base.
For 19F NMR, most solvents used in 1H NMR can be used, the most common being CHCl 3, CCl4,
H2O, CS7, aqueous acids and bases, and dimethylacetamide. In general, any non-fluorinated solvent
can be used whenever spectroscopic calibration is to be performed. Obviously, there is no interference
of protic functional groups with the solvent. However, protic and 19F functional groups in the sample
are J-coupled unless they are uncoupled.
Sample preparation – Solution is prepared in a suitable container and transferred to NMR analysis
tube. Volume required depends on the analysis tube size and the instrument geometry. The solution
level in the test tube should extend above the coils as it is inserted into the probe and rotated. Solute
concentration depends on the experiment objective and type of instrument. Detecting small amounts
of contaminants may require more concentrated solutions.
NMR sample tubes must strictly comply with the tolerance specifications for diameter, wall thickness
and curvature. The most commonly used tubes have an external diameter of 5mm and measure
between 15 and 20 cm. There are microtubes for analyzing small amounts of samples.
Procedure – The tube containing sample is introduced into a probe perpendicular to the magnetic
field. The probe contains an electronic circuit that includes a radio frequency emitter, and accessories
for rotating the tube containing the sample.
The instrument adjusts before each experiment. The rotation speed of the tube containing the sample
is adjusted in such a manner that the rotating sidebands do not interfere with the peaks of interest and
the vortex must not exceed the probe coils. To optimize the instrument performance, the magnetic
compressor gradients can be adjusted in the NMR spectrometers so that the oscillation phenomenon
does not occur.
The computer-aided operation of a NMR spectrometer enables to control the equipment; the
programming of the experiment; data collection and processing. Programming the experiment
involves recording the values of a large number of variables (peaks), including the width of the
spectrum that will be examined (expansion); the duration of the excitation pulse; the data acquisition
time and the waiting period between data acquisition of one sample and the next. The analysis time
for an accumulated is in the order of seconds. The number of accumulations to be acquired depends
on the concentration of the sample; the type of nucleus and the objective with the experiment. At the
end of the experiment, the FID is digitally stored in memory, appearing on the video monitor. This
FID can be processed mathematically to improve resolution or sensitivity and can be converted to
frequency range spectra using Fourier transform. The integration of the peaks results in a graph with
staggered lines. More accurate signals can be obtained when they are integrated separately.
Using NMR spectrometers, qualitative and quantitative data can be obtained. In quantitative
experiments, special precautions must be taken so that the signal areas are proportional to the number
of hydrogens. The waiting times between pulses must be sufficient to allow the total relaxation of all
excited nuclei. This considerably increases the analysis time and some resolution is lost. Qualitative
analysis is usually performed under non-quantitative conditions, with an experiment designed to
obtain a rapid analysis with maximum resolution and sensitivity.
QUALITATIVE ANALYSIS
Comparison of a spectrum described in the literature or that of a reference substance with that of a
sample under analysis can be used to confirm the identity of a compound and detect the presence of
impurities. The NMR spectra of simple structures can be adequately described using numerical values
for chemical shifts, coupling constants and the number of hydrogens corresponding to each signal
(the instruments include programs that generate simulated spectra of substances with this data) .
Experimental details such as solvent, sample concentration and chemical shift reference can also be
added to the spectra.
For unknown samples, NMR analysis, usually accompanied by other analytical information, is a
powerful method for structural elucidation. Chemical shifts provide information about the chemical
environment of the nuclei. There are many publications with correlation tables and rules for analyzing
these chemical shifts. The multiplicity of signals provides important stereochemical information. The
mutual partition of signals from functional groups indicates their proximities. The magnitude of the
coupling constant J between residual hydrogens in substituted aromatic, olefinic or cycloalkyl
structures is used to identify the relative position of the substituents.
There are several special methods (double resonance; chemical exchange; use of shift reagents; two-
dimensional analysis; etc.) to simplify some of the more complex spectra; identify certain functional
groups and determine coupling correlations.
In the double resonance method, in a simple hydrogen system often referred to as the AX system,
each hydrogen appears as a doublet. If we introduce a fluent radiofrequency field at the frequency of
X, while the normal radiofrequency field that maintains the frequency responsible for the resonance
of A, the shift between A and X will be nullified (homonuclear shift). Accordingly, the A signal will
not be coupled, and it now appears as a singlet. Routine 13C spectra are obtained under proton
decoupling conditions that nullify all 13C-1H. heteronuclear couplings. As a result of this decoupling,
carbon signals appear as singlets unless other nuclei that are not uncoupled are present (e.g. 19F, 31P).
Functional groups containing interchangeable hydrogens bonded to heteroatoms such as -OH, -NH2
or -COOH can be identified by quickly exchanging the hydrogens with D2O. To determine the
presence and position of these groups it is necessary to test the substance in CDCl 3 or DMSO-d6
and then add a few drops of D2O to the sample tube, shake and analyze again. The resonance peaks
of these groups collapse in this second analysis and are replaced by singlet HDO between 4.7 and 5.0
ppm.
This chemical exchange serves to exemplify the speed effect of the intermolecular and intramolecular
processes on NMR spectra. If a hydrogen can experience different environments as a result of this
process (tautomerism; rotation around an axis; exchange equilibria; ring inversion; etc.), the
appearance of the spectrum will be a function of the process speed. Slow processes (time scale in
NMR) provide more than one signal, whereas fast processes provide narrow signals, and other
intermediate processes large signals.
The computing programs in NMR devices contain a sequence of varied pulses with the repetitive
accumulation of transients described above. These experiments include two-dimensional
homonuclear or heteronuclear analyses, which determine the correlation of couplings and can
simplify the interpretation of more complex spectra.
QUANTITATIVE ANALYSIS
If the instrument is correctly calibrated for quantitative analysis, the areas under the peaks are
proportional to the total number of hydrogens that generate them.
A1/A2 = N1/N2
If the peaks originate from functional groups of the same molecule, the formula can be simplified
A1/A2 = N1/n2
Where n1 and n2 are the number of hydrogens in the respective functional groups.
Where m1 and m2 are the number of moles; W 1 and W2 are the masses, and M 1 and M2 are the molar
masses of compounds 1 and 2 respectively.
The analysis of the formulas above makes it possible to verify that the quantitative analysis by NMR
can be performed in an absolute or relative manner. In the absolute method, an internal standard must
be added to the sample and the area under the resonance peak arising from the test substance must be
compared with the area under the resonance peak of the internal standard. If such substances are
exactly equivalent, the quantity of the substance can be calculated. A good internal standard must
have the following properties: present a reference resonance peak, preferably singlet, in a field
position distinct from all peaks in the sample; be soluble in the solvent used; no proton equivalent
weight (when the weight divided between the number of hydrogens that generate a reference peak is
low) and does not interact with the compound under analysis. The choice of internal standard will be
dictated by the spectrum of the sample.
The relative method can be used to determine the molar fraction of an impurity in a sample (or
components of a mixture) using the aforementioned formula.
Quantitative analyses and detection of impurity traces have improved with the development of
modern instruments.
Generally, tests for residual solvents are not mentioned in the individual monographs when the limits
to be applied are in accordance with those indicated below, as the solvents employed may vary from
one manufacturer to another.
The purpose of this chapter is to inform the acceptable amounts of residual solvents in
pharmaceuticals for patient safety. The chapter recommends the use of less toxic solvents and
describes levels considered toxicologically acceptable for some residual solvents.
For pharmacopoeial purposes, residual solvents in pharmaceuticals are defined as volatile organic
chemicals that are used or produced during the manufacture of active pharmaceutical ingredients or
excipients, or in the preparation of finished products. Residual solvents are not completely removed
during manufacturing process.
This chapter does not deal with solvents that are used as excipients or with solvates. However, the
solvent content in such products must be evaluated and justified.
Pharmaceutical products must not contain amounts of residual solvents higher than those allowing
for safety data. Avoid the use of solvents that cause unacceptable toxicity (Class 1, Table 3) in the
production of active pharmaceutical ingredients, excipients or finished products, unless their use can
be strongly justified by a risk-benefit assessment. The use of solvents associated with less severe
toxicity (Class 2, Table 4) should be limited to protect patients from potential adverse effects. In an
ideal situation, the least toxic solvents (Class 3, Table 5) should be used. In Appendix 1, the complete
list of solvents included in this chapter is presented. These tables and list are not mutually exclusive.
APPLICATION SCOPE
Active pharmaceutical ingredients, excipients and finished products must be analyzed to detect the
presence of residual solvents when it is known that purification or production processes may result in
the presence of such solvents.
It is necessary to carry out the tests for solvents that are used or produced in the purification or
manufacture of active pharmaceutical ingredients, excipients or finished products, even when the test
is not indicated in the individual monograph.
Although manufacturers may choose to test the finished product, a cumulative procedure can be used
to calculate the levels of residual solvents present in the finished product from the levels in the
ingredients used to produce the finished product. If the calculations result in a level equal to or lower
than that given in this general chapter, carrying out the residual solvent test on the finished product is
not required.
However, if the calculated level is above the recommended level, the finished product must be
analyzed to determine if the formulation process has reduced the corresponding solvent level to the
acceptable amount. A finished product must also be analyzed if any solvent is used during its
manufacture.
GENERAL PRINCIPLES
The term permitted daily exposure (PDE) is defined as the maximum allowable intake of residual
solvents from pharmaceuticals.
Residual solvents that are evaluated in this chapter are listed in Appendix 1 according to their
chemical structure and common name. They were evaluated according to the risk they pose to human
health and placed in one of the three classes below:
There are two options to set the limits of Class 2 residual solvents.
Option 1 – Concentration limits in ppm shown in Table 4 are used. These limits were calculated using
the formula below, assuming a product weight of 10 g, administered daily.
In this case, PDE is expressed in mg per day and the dose is expressed in g per day.
These limits are considered acceptable for all active pharmaceutical ingredients, excipients and
finished products. Therefore, this option can be applied if the daily dose is not known or has not been
defined. If all active pharmaceutical ingredients and excipients in a formulation comply with the
limits given in Option 1, these components can be used in any proportion. It is not necessary to
perform additional calculations as long as the daily dose does not exceed 10 g. Products that are
administered in doses higher than 10 g per day are listed in Option 2.
Option 2 - Each component of the finished product is not required to comply with the limits set in
Option 1. PDE, expressed in mg per day, as indicated in Table 4, with the maximum known daily
dose and the formula mentioned above, can be used to determine the concentration of residual solvent
allowed in a finished product.
Such limits are considered acceptable if it can be proved that the residual solvent has been reduced to
the minimum possible. Limits must be realistic regarding analytical accuracy, manufacturability, and
reasonable variation in the manufacturing process. The limits must also meet current manufacturing
standards.
Option 2 can be applied by adding the amount of residual solvents present in each of the components
of the finished product. The sum of the amount of solvent per day must be lower than indicated by
the PDE.
Below is an example of the application of Option 1 and Option 2 for the concentration of acetonitrile
in a finished product. The permitted daily exposure for acetonitrile is 4.1 mg per day; therefore,
Option 1 limit is 410 ppm. Maximum administered daily weight of a finished product is 5.0 g, which
contains two excipients. The composition of the finished product and the calculated maximum
amount of residual acetonitrile are shown in Table 1.
Table 1 – Example of application of Options 1 and 2 for acetonitrile concentration in a finished product.
Quantity in formulation Acetonitrile content Daily Exposure
Component
(g) (ppm) (mg)
API 0.3 800 0.24
Excipient 1 0.9 400 0.36
Excipient 2 3.8 800 3.04
Finished product 5.0 728 3.64
Excipient 1 complies with Option 1 limit, but API, Excipient 2 and finished product do not comply
with Option 1 limit. However, finished product complies with Option 2 limit of not more than 4.1
mg acetonitrile per day and therefore complies with acceptance criteria in this chapter.
Below is another example using acetonitrile as the residual solvent. Maximum administered daily
weight of a finished product is 5.0 g, which contains two excipients. Composition of finished product
and calculated maximum amount of residual acetonitrile are shown in Table 2.
Table 2 –Example of application of Options 1 and 2 for acetonitrile concentration in a finished product.
Quantity in formulation Acetonitrile content Daily Exposure
Component
(g) (ppm) (mg)
Drug 0.3 800 0.24
Excipient 1 0.9 2000 1.80
Excipient 2 3.8 800 3.04
Pharmaceutical product 5.0 1016 5.08
In this example, finished product does not meet Option 1 or Option 2 limit according to this sum. The
manufacturer must analyze finished product to determine if the formulation process has reduced the
acetonitrile concentration.
If, during formulation, acetonitrile concentration has not been reduced to allowable limits, the
product does not meet the residual solvent limits as described in this chapter, and the pharmaceutical
manufacturer must take other measures to reduce the amount of acetonitrile in the pharmaceutical
product .
Analytical procedures
Typically, residual solvents are determined using chromatographic methods such as gas
chromatography. The official methods for analyzing the content of residual solvents are described in
the item Identification, control and quantification of residual solvents in this chapter.
If Class 3 solvents are present, a non-specific method such as loss on desiccation can be used.
Finished product manufacturers need certain information about the content of residual solvents in
APIs or excipients to meet the criteria in this general chapter. The following statements are provided
as acceptable examples of the information that a manufacturer of APIs or excipients could provide to
a manufacturer of finished products. The manufacturer may choose one of the options below, as
appropriate:
• It is likely that only Class 3 solvents are present. The loss on desiccation is less than 0.5%.
• It is likely that only X, Y, ... Class 2 solvents are present. All are below the Option 1 limit (here
the manufacturer would mention Class 2 solvents, represented by X, Y, ...)
• It is likely that only X, Y, ... Class 2 and Class 3 solvents are present. Class 2 residual solvents are
below the Option 1 limit and Class 3 residual solvents are below 0.5%.
The phrase "is likely to be present", as used in the examples above, refers to the solvent used or
produced in the final manufacturing step and the solvents used or produced in the initial
manufacturing steps that are not uniformly removed by a validated process.
If Class 1 solvents are likely to be present, these should be identified and quantified. If Class 2 or 3
solvents are present in an amount that exceeds the Option 1 or 0.5% limits, respectively, these must
be identified and quantified.
Class 1 residual solvents (Table 3) should not be used in the manufacture of APIs, excipients or
finished products due to unacceptable toxicity or their harmful environmental effects. However, if its
use in the manufacture of a drug with a significant therapeutic advantage is unavoidable, its levels
should be restricted, as shown in Table 3, unless otherwise indicated in the individual monograph.
The 1,1,1-trichloroethane solvent was included in Table 3 because it represents an environmental
hazard. The stated limit of 1500 ppm is based on review of safety data.
When Class 1 residual solvents are used or produced in the manufacture or purification of APIs,
excipients or finished products and they are not removed during the process, these must be identified
and quantified. The procedures described in item Identification, control and quantification of residual
solvents in this chapter must be applied whenever possible. If this is not possible, a validated
procedure must be used.
Class 2 residual solvents (Table 4) should be limited in APIs, excipients and finished products due
to their inherent toxicity. EDP is supplied to an approximate 0.1 mg per day and concentrations to an
approximate 10 ppm. The values indicated do not reflect the necessary analytical precision of the
determination process. Accuracy should be determined as part of procedure validation.
If Class 2 residual solvents are present in an amount that exceeds the Option 1, these must be identified
and quantified. The procedures described in item Identification, control and quantification of residual
solvents in this chapter must be applied whenever possible. If this is not possible, a validated
procedure must be used.
Note: The following Class 2 residual solvents are not easily detected under the gas phase injection
conditions described in the item Identification, control and quantification of residual solvents in this
chapter: formamide, 2-ethoxyethanol, 2-methoxyethanol, ethylene glycol, N-methylpyrrolidone and
sulfolane. Other appropriate validated procedures for quantification of these residual solvents must
be employed.
Class 3 residual solvents (Table 5) are considered to be less toxic and pose a lower risk to human
health when compared to Class 1 and Class 2 residual solvents. Class 3 does not include solvents that
pose a risk to human health at levels normally accepted in pharmaceutical products. However, there
are no long-term carcinogenicity or toxicity studies for many of the Class 3 residual solvents.
Available data indicate that they are less toxic in acute or short-term toxicity studies and negative in
genotoxicity studies.
Residual solvent amounts of 50 mg per day or less (corresponding to 5000 ppm or 0.5% in Option 1)
would be considered acceptable without justification. Higher amounts may also be acceptable, where
authorized by the relevant regulatory authority, taking into account, among other things, process
capability and good manufacturing practices.
If the limit of a Class 3 solvent in an individual monograph is greater than 50 mg per day, such residual
solvent must be identified and quantified. The procedures described in item Identification, control
and quantification of residual solvents in this chapter must be applied whenever possible with the
required changes of the reference solutions. If this is not possible, another validated procedure must
be used.
The residual solvents listed in Table 6 may also be of interest to manufacturers of APIs, excipients
or finished products. However, adequate toxicological data to support PDE have not yet been found.
Whenever possible, the analyte needs to be dissolved to release the residual solvent. In some cases,
it may be acceptable that some of the components of the formulation do not fully dissolve. In such
cases, it may be necessary to first reduce the pharmaceutical product to a fine powder to release any
residual solvent that may be present. This operation must be carried out as soon as possible to avoid
the loss of volatile solvents during the procedure.
Note: these procedures must be carried out with water free of organic substances to avoid the
presence of peaks that could significantly interfere with the chromatogram.
The following procedures are useful to identify and quantify residual solvents when you do not have
information about which ones might be present in the material, when information about them is not
available. When information on the presence of specific residual solvents is available, it is only
necessary to perform Procedure C to quantify the residual solvents present. Figure 1 presents a flow
diagram for the application of residual solvent limit tests.
PROCEDURE A
No
PROCEDURE B
No
PROCEDURE C
Calculate the amount of
SR found
Yes
No
Abbreviations:
SR-residual solvents
Doe not comply with the
test. SA-sample solution
SP-standard solution
EDP-permitted daily exposure
Figure 1 - Flowchart referring to the identification of residual solvents and the application of limit tests.
Water-soluble substances
Procedure A
Class 1 stock standard solution: [Note: when transferring solutions, place the pipette tip just below
the liquid surface and mix]. Transfer 1.0 mL of the reference standard Class I residual solvent mixture
to a 100 mL volumetric flask to which approximately 9 mL of dimethylsulfoxide has been previously
added, adjust volume with water and homogenize. Transfer 1.0 mL of this solution to a 100 mL
volumetric flask, to which about 50 mL of water were previously added, adjust volume with water
and homogenize. Transfer 10.0 mL of this solution to a 100 mL volumetric flask, to which about 50
mL of water were previously added, complete the volume with water and homogenize.
Class 1 Standard Solution: transfer 1.0 mL of Class 1 Stock Standard Solution to a suitable gas phase
sampling flask containing 5.0 mL of water (place the pipette tip just below the liquid surface for
dispensing), cap and homogenize.
Class 2 stock standard solutions: transfer 1.0 mL of mixture A –Class 2 Residual Solvents reference
standard to a 100 mL volumetric flask, adjust volume with water and homogenize. This is Class 2
stock A Standard Solution. Transfer 1.0 mL of mixture B – Class 2 Residual Solvents reference
standard to a 100 mL volumetric flask, adjust volume with water and homogenize. This is Class 2
stock B Standard Solution.
Class 2 Standard Solution A: transfer 1.0 mL of Class 2 Stock A Standard Solution to a suitable gas
phase sampling flask containing 5.0 mL of water), cap and homogenize.
Class 2 Standard Solution B: transfer 5.0 mL of Class 2 Stock B Standard Solution to a suitable gas
phase sampling flask containing 1.0 mL of water, cap and homogenize.
Stock sample solution: transfer approximately 250 mg of the material under analysis, accurately
weighed, into a 25 mL volumetric flask, dissolve and adjust volume with water and homogenize.
Sample Solution: Transfer 5.0 mL of Stock Sample Solution to a suitable gas phase sampling flask,
add 1.0 mL of water, cap and homogenize.
Class 1 System Suitability Solution: Transfer 1.0 mL of Class 1 Reference Stock Solution to a suitable
gas phase sampling flask, add 5.0 mL of Stock Sample Solution, cap and homogenize.
Chromatographic system: gas chromatograph equipped with flame ionization detector and 0.32mm
× 30 m fused silica column, coated with a phase layer of 6% cyanopropyl phenyl – 94% 1.8 μm
dimethylpolysiloxane, or column of 0.53 mm × 30 m macrocapillary layer, coated with a phase layer
of 6% cyanopropyl phenyl – 94% dimethylpolysiloxane 3.0 μm. The carrier gas is nitrogen or helium
at a linear velocity of approximately 35 cm/s and a partition ratio of 1:5 [Note: the partition ratio can
be modified to optimize sensitivity]. Keep the column temperature at 40°C for 20 minutes; then raise
the temperature to 240°C at a heating rate of 10°C per minute and hold at 240°C for 20 minutes.
Maintain the injector and detector temperatures at 140°C and 250°C, respectively. Inject Class 1
Standard Solution, Class 1 System Suitability Solution, and Class 2 Standard Solution A into the
chromatograph and record the chromatogram as indicated in Procedure. The signal/noise ratio of
1,1,1-trichloroethane in the Class 1 Standard Solution is minimum 5; the signal/ noise ratio of each
peak in the Class 1 System Suitability Solution is minimum 3; and the resolution R between the peaks
of acetonitrile and methylene chloride in Class 2 Standard Solution A is minimum 1.0.
Procedure: [Note: It is recommended to increase the transfer line temperature between runs to
eliminate any potential condensation from the solvents.]. Inject, separately, into the chromatograph
(following the operating parameters for the gas phase injector, as described in Table 7) equal volumes
of the gas phase (1 mL) of Class 1 Standard Solution, Class 2 Standard Solution A, Class 2 standard
solution B and Sample Solution, record the chromatograms and measure the main peak responses. If
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.33-00
the response of any peak other than the 1,1,1-trichloroethane peak in the Sample Solution is higher or
equal to the corresponding peak obtained with the Class 1 Standard Solution or with any peak
obtained with the Class 2 Standard Solutions ( A and B), or if the response of the 1,1,1-trichloroethane
peak is higher or equal to 150 times the corresponding peak response of 1,1,1-trichloroethane obtained
with the Class 1 standard solution, follow as Procedure B to verify peak identity; if no peak is
detected, within the criteria specified above, the sample meets the requirements of this assay.
Procedure B
Class 1 stock standard solution, Class 1 standard solution, Class 2 stock standard solution, Class 2
standard solution A, Class 2 standard solution B, Stock sample solution, Sample solution and Class
1 system suitability solution: prepare as indicated in Procedure A.
Chromatographic system: gas chromatograph equipped with a flame ionization detector and a
0.32 mm × 30 m fused silica column, coated with a 0.25 μm layer of polyethylene glycol
(approximate molecular weight 15 000), or a column 0.53 mm × 30 m macrocapillary, coated with a
0.25 μm polyethylene glycol phase layer (approximate molecular weight 15 000). The carrier gas is
nitrogen or helium at a linear velocity of approximately 35 cm/s and a partition ratio of 1:5 [Note: the
partition ratio can be modified to optimize sensitivity]. Keep the column temperature at 50°C for 20
minutes; then raise the temperature to 165°C at a heating rate of 6°C per minute and hold at 165°C
for 20 minutes. Maintain the injector and detector temperatures at 140°C and 250°C, respectively.
Inject Class 1 Standard Solution, and Class 1 System Suitability Solution into the chromatograph and
record the chromatogram as instructed in Procedure. The benzene signal/noise ratio , in Class 1
Standard Solution, is minimum 5; the signal/noise ratio of each peak in the Class 1 System Suitability
Solution is minimum 3; and the resolution R between the acetonitrile and cis-dichloroethene peaks in
Class 2 Standard Solution A is minimum 1.0.
Procedure: [Note: It is recommended to increase the transfer line temperature between runs to
eliminate any potential condensation from the solvents.]. Inject, separately, into the chromatograph
(following the operating parameters for the gas phase injector, as described in Table 7) equal volumes
of the gas phase (1,0 mL) of Class 1 Standard Solution, Class 2 Standard Solution A, Class 2 standard
solution B and Sample Solution, record the chromatograms and measure the main peak responses. If
responses of the peaks obtained with the Sample Solution, identified in Procedure A, are equal or
higher than the corresponding peaks obtained with the Class 1 Standard Solution or with either of the
two Class 2 Standard Solutions (A and B), proceed according to Procedure C to quantify analytes; if
no peak is detected, within the criteria specified above, the sample meets the assay requirements
Procedure C
Class 1 stock standard solution, Class 1 standard solution, Class 2 stock A standard solution, Class
2 standard solution A, Stock sample solution, Sample solution and Class 1 system suitability solution:
prepare as indicated in Procedure A .
Stock Standard Solution: [Note: Prepare, separately, a Stock Standard Solution for each identified
and confirmed peak as per Procedures A and B. For Class 1 solvents other than 1,1,1-
trichloroethane, prepare the first dilution as described for the first dilution of Class 1 Stock Standard
Solution, Procedure A]. Transfer an accurately measured volume of each reference standard
corresponding to each residual solvent peak identified and confirmed after performing Procedures A
and B to a suitable flask and dilute quantitatively with water to obtain a solution with a final
concentration of 1/20 of the value given in Table 3 or Table 4 (under Concentration Limit).
Standard Solution: Transfer 1.0 mL of the Stock Standard Solution to a suitable gas phase sampling
flask, add 5.0 mL of water, cap and homogenize.
Sample Solution with a known amount added: [Note: separately prepare a Sample Solution with the
addition of a known amount of the analyte from each identified and verified peak as per Procedures
A and B]. Transfer 5.0 mL of Stock Sample Solution to an appropriate vial, add 1.0 mL of Stock
Standard Solution, cap and homogenize.
Chromatographic System: [Note: If it is confirmed that the chromatographic analysis results for
Procedure A are inferior to those observed for Procedure B, the Chromatographic System for
Procedure B may be replaced]. Use a gas chromatograph equipped with a flame ionization detector
and a 0.32 mm × 30 m fused silica column, covered with a 6% cyanopropyl phenyl-94% 1.8 μm
dimethylpolysiloxane phase layer, or a macrocapillary column 0.53 mm × 30 m, overlaid with a phase
layer of 6% cyanopropyl phenyl-94% dimethylpolysiloxane of 3.0 μm. The carrier gas is nitrogen or
helium at a linear velocity of approximately 35 cm/s and a partition ratio of 1:5 [Note: the partition
ratio can be modified to optimize sensitivity]. Keep the column temperature at 40°C for 20 minutes;
then raise the temperature to 240°C at a heating rate of 10°C per minute and keep at 240°C for 20
minutes. Maintain the injector and detector temperatures at 140°C and 250°C, respectively. Inject
Class 1 Standard Solution, Class 1 System Suitability Solution, and Class 2 Standard Solution A into
the chromatograph and record the chromatogram as indicated in Procedure. The signal/noise ratio of
1,1,1-trichloroethane in the Class 1 Standard Solution is minimum 5; the signal/ noise ratio of each
peak in the Class 1 System Suitability Solution is minimum 3; and the resolution R between the peaks
of acetonitrile and methylene chloride, in Class 2 Standard Solution A, is minimum 1.0.
Procedure: [Note: It is recommended to increase the transfer line temperature between runs to
eliminate any potential condensation from the solvents.]. Inject, separately, into chromatograph
(following the operating parameters for the gas phase injector described in Table 7), equal volumes
of the gas phase (1.0 mL) of each standard, Sample Solution and Sample Solution with a known
amount added, record the chromatograms and measure the main peak responses. Calculate the
amount, in ppm, of each residual solvent found in the material under analysis, using the formula:
where
C = concentration, in µg per mL, of the reference standard corresponding to the Stock standard
solution;
W = weight, in g, of the material under analysis, weighed to prepare the Stock Sample Solution;
rU and rST = peak responses of each residual solvent obtained from the Sample Solution and the
Sample Solution with a known added amount, respectively.
Water-insoluble substances
Procedure A
Class 1 stock standard solution: transfer 1.0 mL of the reference standard Class I residual solvent
mixture to a 100 mL volumetric flask to which approximately 80 mL of dimethylformamide has been
previously added, adjust volume with the same solvent and homogenize. Transfer 1.0 mL of this
solution to a 100 mL volumetric flask, to which approximately 80 mL of dimethylformamide has
been previously added, complete the volume with the same solvent and homogenize (reserve a portion
of this solution to prepare the Class 1 System Suitability Solution). Transfer 1.0 mL of this solution
to a 10-mL volumetric flask, adjust volume with dimethylformamide and homogenize.
Class 1 Standard Solution: transfer 1.0 mL of Class 1 Reference Stock Solution to a suitable gas phase
sampling vial, add 5.0 mL of water, cap and homogenize.
Class 2 stock standard solutions: transfer 1.0 mL of Mixture A – Class 2 Residual solvents reference
standard to a 100 mL volumetric flask, to which approximately 80 mL of dimethylformamide has
been previously added, adjust volume with the same solvent and homogenize. This is Class 2 stock
A Standard Solution. Transfer 0,5 mL of Mixture B – Class 2 Residual Solvents reference standard
to a 10 mL volumetric flask, adjust volume with dimethylformamide and homogenize. This is Class
2 stock B Standard Solution.
Class 2 Standard Solution A: Transfer 1.0 mL of Class 2 Stock A Standard Solution to a suitable gas
phase sampling vial, add 5.0 mL of water, cap and homogenize.
Class 2 Standard Solution B: transfer 1.0 mL of Class 2 Stock B Standard Solution to a suitable gas
phase sampling vial, add 5.0 mL of water, cap and homogenize.
Stock sample solution: transfer approximately 500 g of the material under analysis, accurately
weighed, into a 10 mL volumetric flask, dissolve and adjust volume with dimethylformamide and
homogenize.
Sample Solution: Transfer 1.0 mL of the Stock Sample Solution to a suitable gas phase sampling vial,
add 5.0 mL of water, cap and homogenize.
Class 1 System Suitability Solution: homogenize 5 mL of the Stock Sample Solution with 0.5 mL of
the reserved Intermediate dilution of the Class 1 Stock Standard Solution. Transfer 1.0 mL of this
solution to a suitable gas phase sampling vial containing 5.0 mL of water, cap and homogenize.
Chromatographic system: gas chromatograph equipped with a flame ionization detector and a
0.53mm × 30m macrocapillary column, covered with a 6% cyanopropyl phenyl- 94%
dimethylpolysiloxane phase layer of 3.0μm. The carrier gas is helium at a linear velocity of
approximately 35 cm/s and a partition ratio of 1:3 [Note: the partition ratio can be modified to
optimize sensitivity]. Keep the column temperature at 40°C for 20 minutes; then raise the temperature
to 240°C at a heating rate of 10°C per minute and keep at 240°C for 20 minutes. Maintain the injector
and detector temperatures at 140°C and 250°C, respectively. Inject Class 1 Standard Solution, Class
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.2.33-00
1 System Suitability Solution, and Class 2 Standard Solution A into the chromatograph and record the
chromatogram as indicated in Procedure. The signal/noise ratio of 1,1,1-trichloroethane in Class 1
Standard Solution is minimum 5; the signal/ noise ratio of each peak in Class 1 System Suitability
Solution is minimum 3; and resolution R between acetonitrile and methylene chloride, in Class 2
Standard Solution A, is minimum 1.0.
Procedure: [Note: It is recommended to raise the transfer line temperature between runs to eliminate
any potential condensation of solvents.] Inject separately into the chromatograph (use the operating
parameters for the gas phase injector described in column 3 of Table 7, with a vial pressure of 10
psi), equal volumes of gas phase (1.0,mL) of Class 1 Standard Solution, Class 2 Standard Solution
A, Class 2 Standard Solution B, and Sample Solution, record the chromatograms and measure the
main peak responses. If the response of any peak other than the 1,1,1-trichloroethane peak in the
Sample Solution is superior or equal to the corresponding peak obtained with the Class 1 Standard
Solution or with any peak obtained with the Class 2 Standard Solutions ( A and B), or if the response
of the 1,1,1-trichloroethane peak is higher than or equal to 150 times the corresponding peak response
of 1,1,1-trichloroethane obtained with the Class 1 standard solution, follow as per Procedure B to
verify peak identity; if no peak is detected, within the criteria specified above, the sample meets the
requirements of this assay.
Procedure B
Class 1 Stock Standard Solution, Class 1 Standard Solution, Class 1 System Suitability Solution, Class
2 Stock Standard Solutions, Class 2 Standard Solution A, Class 2 Standard Solution B, Stock Sample
Solution and Sample Solution: prepare as described in Procedure A.
Chromatographic system: proceed as described in Procedure B for Water Soluble Materials with a
1:3 partition ratio. Note: The partition ratio can be modified to optimize sensitivity.
Procedure: [Note: It is recommended to increase transfer line temperature between runs to eliminate
any potential condensation from solvents]. Inject, separately, into chromatograph (use the operating
parameters for the gas phase injector described in column 3 of Table 7 with a vial pressure of 10 psi),
equal volumes of the gas phase (approximately 1.0 mL) of Class 1 standard solution, Class 2
Standard Solution A, Class 2 Standard Solution B, and Sample Solution, record the chromatograms
and measure the main peak responses. If responses of the peaks obtained with the Sample Solution,
identified in Procedure A, are equal to or higher than the corresponding peaks obtained with the Class
1 Standard Solution or with either of the two Class 2 Standard Solutions (A and B), proceed according
to Procedure C to quantify analytes; if no peak is detected, within the criteria specified above, the
sample meets the assay requirements.
Procedure C
Class 1 Stock Standard Solution, Class 1 Standard Solution, Class 1 System Suitability Solution, Class
2 Stock A Standard Solution, and Class 2 Standard Solution A: Proceed as described in Procedure A.
Stock Standard Solution: [Note: separately prepare a Stock Standard Solution for each identified and
verified peak as per Procedures A and B. For Class 1 solvents other than 1,1,1-trichloroethane,
prepare the first dilution as described for the first dilution of Class 1 Stock Standard Solution in
Procedure A.] Transfer an accurately measured volume of each individual reference standard
corresponding to each residual solvent peak identified and verified in Procedures A and B into a
suitable container and dilute quantitatively with water to obtain a solution with a final concentration
of 1/20 of the value specified in Table 3 or Table 4 (Concentration Limit).
Standard Solution: Transfer 1.0 mL of the Stock Standard Solution to a suitable gas phase sampling
flask, containing 5.0 mL of water, cap and homogenize.
Sample Solution: Transfer 1.0 mL of the Stock Sample Solution to a suitable gas phase sampling vial,
containing 5.0 ml of water, cap and homogenize.
Sample Solution with a known amount added: [Note: separately prepare a Sample Solution with the
addition of a known amount to each peak identified and verified as per Procedures A and B]. Transfer
1.0 mL of the Stock Sample Solution to a suitable gas phase sampling flask, add 1 mL of Standard
solution and 4.0 mL of water, cap and homogenize.
Procedure: [Note: It is recommended to increase transfer line temperature between runs to eliminate
any potential condensation from solvents. Inject, separately, into chromatograph (use the operating
parameters for the gas phase injector described in column 3 of Table 7 with a vial pressure of 10 psi),
equal volumes of the gas phase (approximately 1.0 mL) of Standard Solution, Sample Solution and
Sample Solution with a known amount added, record the chromatograms and measure the main peak
responses. Calculate the amount, in ppm, of each residual solvent found in the material under analysis,
using the formula:
where
C = concentration, in µg per mL, of the reference standard corresponding to Stock standard solution;
W = weight, in g, of the material under analysis to prepare Stock Sample Solution;
rU and rST =peak responses of each residual solvent obtained from Sample Solution and Sample
Solution with a known added amount, respectively.
If Class 3 solvents are present, level of residual solvents can be determined according to the Loss on
Desiccation method when the analyte monograph includes a loss on desiccation procedure that
specifies an upper limit of maximum 0. 5% (according to Option 1 in this general chapter), or can be
carried out by solvent specific determination. If analyte monograph does not include a loss on
desiccation procedure or if Class 3 solvent limit in the individual monograph is higher than 50mg per
day (which corresponds to 5000ppm or 0.5% - Option 1), the individual residual solvent of Class 3
or solvents present in the test substance must be identified and quantified, applying the procedures
described above, with the necessary modifications in the standard solutions, whenever possible. If
this is not the case, an appropriate validated procedure must be employed.
Chlorobenzene Class 2
Classic methods for identification of functions or certain chemical groups present in drugs consist of
reactions that result in precipate formation, colored product, gas release, discoloration of the used
reagent or any other easily noticeable phenomenon. Employ one of the methods described below for
each ion, group, or function.
Acetate
1) Heat sample with an equal amount of oxalic acid; Acid vapors are released with a characteristic
odor of acetic acid.
2) Heat sample with sulfuric acid RS and ethyl alcohol; ethyl acetate is released, with a characteristic
odor.
3) Treat neutral sample solution with ferric chloride RS; a dark red coloration is produced which
disappears when mineral acids are added.
4) Dissolve sample in water, add five drops of lanthanum nitrate RS, two drops of 0.1 M iodine and
one drop of concentrated ammonia solution. Carefully heat to boiling. After a few minutes, a blue
precipitate forms or an intense blue color appears.
Acetyl
Place sample in a test tube and add three drops of phosphoric acid RS. Close the tube with a lid
crossed by another smaller test tube filled with water and on the outside of which a drop of lanthanum
nitrate RS has been deposited. Heat in water bath for five minutes (certain acetylation substances
hydrolyze with difficulty; in this case, the mixture must be heated slowly up to boiling over direct
flame). Transfer the lanthanum nitrate RS drop to a porcelain dish and homogenize with a drop of
iodine RS. Place a drop of 2 M ammonium hydroxide on the edge of the mixture. In the contact zone
of the two liquids, a blue color slowly appears and persists for a short time.
Alkaloid
Dissolve a few milligrams of the sample in 5 mL of water, add hydrochloric acid RS until solution
becomes acidic, add 1 mL of potassium iodobismuthate solution; an orange or red-orange precipitate
is immediately formed.
Aluminum, ion
2) Transfer to sample sodium hydroxide M or sodium sulfide RS; a white gelatinous precipitate is
formed, soluble in excess of the same reagent.
3) Transfer 5 M ammonium hydroxide to sample solution until turbidity is formed. Then add three
to four drops of the freshly prepared solution of 0.05% quinalizarin in 1% sodium hydroxide (w/v).
Heat to boiling, cool and acidify with excess 5 M acetic acid; a reddish-violet color is produced.
Acidify sample solution with 2 M hydrochloric acid and add four drops of sodium nitrite RS. After
one to two minutes, add 1 mL of 2-naphthol RS; an intense orange or red color arises, generally
forming a precipitate.
Dissolve the sample in a test tube, add magnesium oxide and heat if necessary; alkaline vapors are
gradually released, which darkens the silver-manganese paper placed in the upper part of the tube.
Ammonium, ion
Transfer excess M sodium hydroxide cold to sample; ammonia is released, with a characteristic odor,
which changes litmus paper red color to blue. Decomposition is accelerated by heating.
Antimony(III), ion
1) Treat sample solution, strongly acidified with hydrochloric acid (maximum 2 M), with hydrogen
sulfide RS; an orange precipitate of antimony sulfide forms, insoluble in 6 M ammonium hydroxide,
but soluble in ammonium sulfide RS, 2 M sodium hydroxide and concentrated hydrochloric acid.
2) Dissolve sample in potassium sodium tartrate RS; after cooling, add, dropwise, sodium sulfide
RS1; a red-orange precipitate is formed soluble in 2 M sodium hydroxide.
Arsenic
1) To a sample ammoniacal solution, transfer sodium sulfide RS and acidify with dilute hydrochloric
acid; a yellow precipitate forms, insoluble in hydrochloric acid, but soluble in alkaline solutions.
2) Heat 5 mL of sample solution, strongly acidified with hydrochloric acid, in water bath with an
equal volume of sodium hypophosphite RS; a brown to black precipitate is formed. In As(V), the
reduction is slower; addition of potassium iodide RS will exert a catalytic effect.
To a sample methanolic solution, transfer a few drops of a solution containing 10% (w/v) cobalt(II)
nitrate and 10% (w/v) calcium chloride, homogenize and add, while shaking, a few drops of 2M
sodium hydroxide; a blue-violet precipitate is formed.
Barium ion
1) Treat sample solution with M sulfuric acid; a white precipitate is formed, insoluble in hydrochloric
and nitric acids.
2) Place sample in the flame reducing zone; it takes on a yellowish-green color, which appears blue
when viewed through green glass.
Benzoate
1) Treat neutral sample solution with ferric chloride RS; a dark yellow precipitate is formed, soluble
in ethyl ether.
2) Acidify moderately concentrated sample solution with M sulfuric acid; a precipitate of benzoic
acid is formed, freely soluble in ethyl ether.
Bicarbonate
1) Treat sample with mineral acid; effervescence is produced with the release of colorless gas which,
when reacted with calcium hydroxide RS, immediately forms a white precipitate.
2) To a cold sample solution transfer phenolphthalein TS; the solution remains unchanged or is only
slightly colored.
Bismuth, ion
Dissolve sample in a slight excess of nitric or hydrochloric acid and dilute with water; a white
precipitate is formed which, treated with hydrogen sulfide, turns brown. The resulting compound is
soluble in a hot mixture of equal parts of nitric acid and water, but insoluble in ammonium sulfide
RS.
Bisulfite
Treat sample with 3 M hydrochloric acid; sulfur dioxide is released, recognized for its characteristic
pungent odor and for darkening filter paper moistened with mercury(I) nitrate RS.
Borate
1) To a sample solution acidified with hydrochloric acid, transfer a few drops of 0.1% iodine solution
(w/v) and 2% polyvinyl alcohol solution (w/v); an intense green color is produced. The reaction is
altered by oxidizing or reducing agents.
2) Treat sample with sulfuric acid, add methyl alcohol and ignite the mixture; it burns with green
edges flame.
Bromide
1) Transfer chlorine water RS to the sample solution acidified with sulfuric acid RS; bromine is
released, which gives a brown color to the solution; by shaking with chloroform, solvent becomes red
to reddish-brown in color whereas aqueous layer remains colorless.
2) Treat sample solution with nitric acid RS and silver nitrate RS; a slightly yellowish white caseous
precipitate is formed, insoluble in nitric acid and slightly soluble in 6 M ammonium hydroxide.
Calcium, ion
1) Moisten sample with hydrochloric acid and take it to the flame reducing area; a transient red-
orange color appears.
2) Dissolve the sample, add two drops of methyl red TS, neutralize with 6 M ammonium hydroxide,
add 3 M hydrochloric acid, drop by drop, until solution becomes acidic and pour ammonium oxalate
RS; a white precipitate of calcium oxalate is formed, insoluble in 6 M acetic acid, but soluble in
hydrochloric acid RS.
Carbonate
1) Treat the sample with mineral acid; effervescence is produced with the release of colorless gas
which, when reacted with calcium hydroxide RS, immediately forms a white precipitate.
2) To a cold solution of the soluble sample, transfer phenolphthalein TS; red color is formed.
Lead, ion
1) Treat sample solution with M sulfuric acid; a white precipitate forms, insoluble in 3 M
hydrochloric acid or 2 M nitric acid, but soluble in heated M sodium hydroxide, 10% (w/v)
ammonium acetate and in an excess of M sulfuric acid.
2) Treat sample solution, free of mineral acids, with potassium chromate RS; a yellow precipitate is
formed, insoluble in 6 M acetic acid, but soluble in hot M sodium hydroxide and nitric acid.
Cyanide
Treat the sample solution with ferrous sulfate RS, sodium hydroxide RS and ferric chloride RS, heat
to boiling and acidify with hydrochloric acid; a blue color or precipitate is formed. If the amount of
cyanide present is small, a blue-greenish colloidal solution is formed.
Citrate
Chlorate
1) Treat sample solution with silver nitrate RS in nitric acid RS medium; no precipitate is formed.
Pour sulfurous acid or fresh sodium nitrite RS solution into this mixture; a white precipitate forms,
insoluble in nitric acid RS, but soluble in 6 M ammonium hydroxide.
3) In a fume hood, treat the dry sample with sulfuric acid; crackles occur with greenish-yellow gas
being released. For this test, use a small amount of chlorate, and extreme care must be taken when
carrying it out, as the gas formed decomposes explosively above 45°C.
Chloride
1) With silver nitrate RS, chloride solutions produce a white lumpy precipitate, which is insoluble in
nitric acid but soluble in a slight excess of 6 M ammonium hydroxide.
2) When analyzing amine hydrochlorides, including alkaloids, which do not respond to the above
test, one drop of diluted nitric acid and 0.5 mL of silver nitrate RS in 2 mL of the solution under
analysis containing approximately 2 mg of chloride ion. A white, lumpy precipitate should form.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.1-00
Immediately centrifuge the mixture and decant the supernatant layer. Wash precipitate with three
1 mL portions of nitric acid solution (1 in 100) and discard supernatants. Transfer a few drops of
ammonia RS to the precipitate. The precipitate will quickly dissolve.
3) When a monograph specifies that the solid substance responds to the tests for chlorides,
homogenize the sample with the same quantity of manganese dioxide, moisten with sulfuric
acid and moderately heat the mixture. If chlorine is produced, it is recognized by the production of a
blue color on paper moistened with iodized starch.
1) Treat sample solution with potassium ferrocyanide RS; a reddish-brown precipitate is formed,
insoluble in dilute acids but soluble in ammonium hydroxide.
2) Treat sample solution with hydrochloric acid and metallic iron filings; a red metallic copper film
is deposited.
3) Treat sample solution with 6 M ammonium hydroxide excess; a bluish precipitate is formed first
and then a strongly bluish solution.
Ester
Transfer to sample a 7% (w/v) hydroxylamine hydrochloride solution in methyl alcohol and 10%
(w/v) potassium hydroxide solution in ethyl alcohol, heat to boiling, cool, acidify with hydrochloric
acid RS and add ferric chloride TS solution; a bluish-red or red color is produced.
Iron
Treat sample with ammonium sulfide RS; a black precipitate is formed, which dissolves in 3 M
hydrochloric acid, with the release of hydrogen sulphide gas, characterized by lead acetate paper.
Ferric, ion
1) Treat acidic sample solution with potassium ferrocyanide RS; a dark blue precipitate is formed,
which does not dissolve by addition of hydrochloric acid RS, but is decomposed by 2 M sodium
hydroxide.
2) Treat sample with ammonium thiocyanate RS; it produces an intense red color that does not
disappear with the addition of dilute mineral acids, but can be extracted with ethyl ether, passing the
red color to the ether layer.
Ferrous, Ion
1) Treat sample solution with potassium ferricyanide RS; a dark blue precipitate is formed, insoluble
in 3 M hydrochloric acid, but decomposed by M sodium hydroxide.
2) Treat sample solution with M sodium hydroxide; a greenish-white precipitate is formed, which
rapidly turns green and then, when shaken, brown.
1) Treat sample neutral solution with silver nitrate RS; a yellow precipitate is formed, soluble in 2 M
nitric acid or 6 M ammonium hydroxide.
2) Treat sample nitric solution with ammonium molybdate RS; a yellow precipitate is formed, soluble
in 6 M ammonium hydroxide; the reaction is accelerated by heat.
Hypophosphite
1) Heat sample solution, acidified with sulfuric acid RS, with cupric sulfate RS; a red precipitate is
formed.
2) Treat sample solution with mercuric chloride RS; a white precipitate is formed, which turns gray
in the presence of hypophosphite excess.
Iodide
1) Treat sample solution with chlorine water RS, drop by drop; iodine is released, which changes the
color of the solution from yellow to red; shaking this solution with chloroform makes it violet in
color.
2) Treat acidified sample solution with nitric acid RS, with silver nitrate RS; a yellow caseous
precipitate is formed, insoluble in nitric acid RS and 6 M ammonium hydroxide.
Lactate
Treat sample solution, acidified with sulfuric acid RS, with potassium permanganate RS and heat the
mixture; acetaldehyde is released, identified by the characteristic odor.
Lithium, ion
1) Treat sample solution moderately concentrated and made alkaline by sodium hydroxide RS with
sodium carbonate RS; a white precipitate is formed on heating, soluble in ammonium chloride RS.
2) Moisten sample with hydrochloric acid and heat in the flame reducing zone; this acquires an
intense red color.
Magnesium, ion
1) Treat sample solution with sodium hydroxide RS; a white precipitate is formed, which dissolves
with the addition of ammonium chloride RS.
2) Treat sample solution, in the presence of ammonium chloride RS, with ammonium carbonate RS;
no precipitate is formed, but when dibasic sodium phosphate heptahydrate RS is added, a white
crystalline precipitate is formed, insoluble in 6 M ammonium hydroxide.
Mercury
1) Treat sample solution with hydrogen sulfide RS; a black precipitate is formed, insoluble in
ammonium sulfide RS and in boiling 2 M nitric acid.
2) Apply sample solution, without nitric acid excess, on a shiny copper slide; a deposit is formed
which, when polished, becomes shiny and silvery.
2) Treat sample neutral solution with potassium iodide RS; a scarlet precipitate is formed, very
soluble in excess of reagent.
1) Treat sample with M sodium hydroxide; decomposition occurs, generating black color.
2) Treat sample solution with hydrochloric acid RS; a white precipitate is formed, which darkens
when treated with 6 M ammonium hydroxide.
3) Treat sample solution with potassium iodide RS; a yellow precipitate is formed which, over time,
may turn green.
Nitrate
1) In a fume hood, heat sample with sulfuric acid and metallic copper; brown red vapors are released.
2) Treat sample solution with an equal volume of sulfuric acid, cool the mixture and add 0.5 mL of
0.5 M ferrous sulfate solution; a brown to purple color is produced on the interface.
Nitrite
1) In a fume hood, treat sample with diluted mineral acids or 5 M acetic acid; brown vapors are
released.
2) Treat iodized starch paper with sample solution; the indicator turns blue.
Oxalate
1) Treat neutral or alkaline solution of the sample with calcium chloride RS; a white precipitate is
formed, insoluble in 6 M acetic acid but soluble in hydrochloric acid.
2) Treat hot acidified sample solution with potassium permanganate RS; the color fades.
Permanganate
1) Treat sample solution, acidified by sulfuric acid RS, with 3% hydrogen peroxide (w/v) RS; the
color fades when cold.
2) Treat sample solution, acidified by sulfuric acid RS, with oxalic acid RS in a heated solution; the
color fades.
Peroxide
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.1-00
Treat sample solution, slightly acidified by sulfuric acid RS, with potassium dichromate RS; an
intense blue color appears. Shaking the mixture with an equal volume of ethyl ether and letting the
liquids separate, the blue color passes into the ether layer.
Potassium, ion
1) Treat sample alkaline solution with 1% sodium tetraphenylborate (w/v); a white precipitate is
formed.
2) Treat sample solution with acetic acid RS and 1 mL of sodium cobaltinitrite RS; a yellow or
orange-yellow precipitate is formed immediately, in the absence of ammonium ions.
3) Place sample solution, acidified with hydrochloric acid RS, in the flame reducing zone; it acquires
a violet color; the presence of a small amount of sodium masks the color.
4) Treat sample solution with perchloric acid RS; a white crystalline precipitate is formed.
Silver, ion
1) Treat sample solution with hydrochloric acid; a white caseous precipitate is formed, insoluble in
nitric acid RS, but freely soluble in 6 M ammonium hydroxide.
2) Treat sample solution with 6 M ammonium hydroxide and a small amount of formaldehyde
solution; by heating, a metallic silver mirror is deposited on the surface of the container.
Salicylate
1) Treat the diluted sample solution with ferric chloride RS; violet color is produced.
2) Treat moderately concentrated sample solution with mineral acid; a white crystalline precipitate
of salicylic acid is formed, which melts at 156 to 160°C.
Sodium, ion
1) Place the sample solution, acidified, with hydrochloric acid RS, in the flame reducing zone; it
acquires an intense yellow color.
2) Treat the sample solution with hydrochloric or nitric acid and then with uranyl acetate and zinc
RS; a yellow-gold crystalline precipitate is formed after shaking for a few minutes.
Succinate
1) Treat neutral sample solution with ferric chloride RS; a light brown precipitate is formed.
2) Treat sample neutral solution with silver nitrate RS; a white precipitate is formed, freely soluble
in 6 M ammonium hydroxide.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.1-00
Sulfate
1) Treat sample solution with barium chloride RS; a white precipitate is formed, insoluble in
hydrochloric acid RS and nitric acid RS.
2) Treat sample solution with lead acetate RS; a white precipitate is formed, soluble in ammonium
acetate RS, but insoluble in hydrochloric or nitric acid RS.
3) Treat sample solution with hydrochloric acid RS; no precipitate is formed (distinction from
thiosulfate).
Sulfite
1) Treat sample with 3 M hydrochloric acid; sulfur dioxide is released, recognized for its
characteristic pungent odor and for darkening filter paper moistened with mercury(I) nitrate RS.
2) Acidify sample solution with hydrochloric acid RS, heat with a few drops of potassium
permanganate RS and add drops of barium chloride RS; a white precipitate is formed.
Tartrate
1) Dissolve a few milligrams of the sample in water, acidified with acetic acid RS, add one drop of
ferrous sulfate solution at 1% (w/v) and one drop of hydrogen peroxide at 3% (w/v); it produces a
fleeting yellow color. Add 2 M sodium hydroxide drop by drop; an intense blue color is produced.
2) Acidify sample solution with M sulfuric acid, add a few drops of resorcinol 2% (w/v) and sulfuric
acid, carefully, so as to form two layers; heating in water bath for a few minutes, a red ring appears
on the interface.
Thiocyanate
Treat sample solution with ferric chloride RS; it produces a red color, which does not disappear with
the addition of moderately concentrated mineral acids and can be extracted with ethyl ether, passing
the red color to the ether layer.
Thiosulfate
1) Treat sample solution with hydrochloric acid; a white precipitate is formed, which soon turns
yellow, and sulfur dioxide is released, recognized by the odor.
2) Treat sample acetic solution with ferric chloride RS; it produces a dark violet color that quickly
disappears.
Xanthine
Treat sample with two drops of concentrated solution of concentrated hydrogen peroxide solution and
five drops of 2 M hydrochloric acid, and heat to dryness in water bath; a yellowish-red residue is
obtained which, treated with 2 M ammonium hydroxide, changes to red-violet.
Zinc, ion
1) Treat sample solution with potassium ferrocyanide RS; a white precipitate is formed, insoluble in
3 M hydrochloric acid
2) Treat neutral or alkaline solution of the sample with ammonium sulfide RS; a white precipitate is
formed.
3) Treat sample solution with 2 M sodium hydroxide solution, dropwise; a white, flaky precipitate is
formed, soluble in excess of sodium hydroxide RS.
Prepare chromatoplate using Kieselguhr G as support. Introduce chromatoplate into the tank
containing the impregnation solvent and allow to develop until the solvent reaches the chromatoplate
top. Remove chromatoplate from the tank and allow solvent to evaporate. Prepare 0.25% (w/v)
sample solution and 0.25% (w/v) standard solution using, as solvent, a mixture of nine volumes of
chloroform and one volume of methyl alcohol. If not specified in the monograph, apply to
chromatoplate 2 μL of sample solution, 2 μL of standard solution and 2 μL of the 1:1 mixture of
sample and standard solutions. Develop the chromatogram with the mobile phase specified in the
monograph, letting it rise in the same direction as the impregnation solvent. Remove chromatoplate
from the tank, allow mobile phase to evaporate, heat chromatoplate at 120°C for 15 minutes and
nebulize with a 10% (v/v) sulfuric acid solution in 96% ethyl alcohol. Heat at 120°C for another 10
minutes, allow to cool and examine under normal visible and ultraviolet light (366nm). The main spot
of the chromatogram obtained with the sample solution will correspond to the main spot obtained in
the chromatogram of the standard solution. The main stain resulting from the application of the
mixture of sample and standard solutions will appear as single and compact.
Impregnation solvents:
I - Mixture of formamide and acetone (1:9).
II - Mixture of 1,2-propanediol and acetone (1:9).
III - Mixture of liquid paraffin and petroleum ether with a boiling range of 40°C to 60°C (1:9).
Mobile phases:
A – Chloroform.
B – Mixture of toluene and chloroform (3:1). C – Toluene
D – Mixture of cyclohexane and toluene (4:1).
E – Mixture of cyclohexane and petroleum ether with a boiling range of 40°C to 60°C (1:1).
F – Mixture of glacial acetic acid and water (2:3).
G – Mixture of hexane and dioxane (8:2).
PROCEDURE I
Proceed as described in Thin Layer Chromatography (5.2.17.1), using silica gel G as support. Prepare
three solutions using, as a solvent, a mixture of chloroform and methyl alcohol (9:1) in the following
concentrations: Solution (1): 1.5% (w/v) sample solution; Solution (2): Chemical Reference
Substance (CRS) solution corresponding to 1.5% (w/v) and Solution (3): Prednisolone CRS solution
and 0.03% (w/v) cortisone acetate CRS solution. Apply 1 μL of each newly prepared solution to the
chromatoplate separately. Develop the chromatogram using, as a mobile phase, a mixture of
methylene chloride, ethyl ether, methyl alcohol, water (77:15:8:1.2). Conduct chromatogram.
Remove the plate and allow to air dry, heat at 105ºC for 10 minutes and nebulize with alkaline
tetrazolium blue RS solution. Examine under visible light. The main spot of the chromatogram
obtained with Solution (1) corresponds, in position, color and intensity, to the main spot of the
chromatogram obtained with Solution (2). Any secondary spot obtained with Solution (1) is not more
intense than the corresponding spot in the chromatogram obtained with Solution (3).
PROCEDURE II
Chromatograph using silica gel G as support and, as mobile phase, a mixture of 1,2-dichloroethane,
methyl alcohol and water (95:5:0.2). Apply on the chromatoplate, separately, 1 μL of each of the
three solutions in a mixture of chloroform and methyl alcohol (9:1), as in Procedure I, except for
Solution 3, in which CRS deoxycortone acetate is added.
PROCEDURE I
Proceed as described in Thin Layer Chromatography (5.2.17.1), using silica gel H as support. Prepare
two solutions using a mixture of ethyl alcohol and 13.5 M ammonium hydroxide (9:1) as a solvent:
Solution (1): 0.005% (w/v) sample solution and Solution (2): 0.005% (w/v) sulfanilamide CRS
solution. Apply 10 μL of each prepared solution to chromatoplate separately. Develop chromatogram
using a mixture of butyl alcohol and M ammonium hydroxide (15:3). Remove the plate and allow to
air dry, heat at 105ºC for 10 minutes and nebulize with a 0.1% (w/v) solution of 4-
dimethylaminobenzaldehyde in ethyl alcohol, containing 1% hydrochloric acid (v/v). Examine under
visible light. Any secondary stain obtained in the chromatogram with Solution 1, different from the
main spot, is not more intense than that obtained in the chromatogram with Solution 2.
PROCEDURE II
Proceed as described in Thin Layer Chromatography (5.2.17.1), using silica gel H as support. Apply
on chromatoplate, separately, 10μL of each of the following solutions prepared in a mixture of ethyl
alcohol and 13.5 M ammonium hydroxide (9:1): Solution (1): 0.25% (w/v) sample solution and
Solution (2): 0.00125% (w/v) sulfanilamide CRS solution. Develop the chromatogram using a
mixture of chloroform, methyl alcohol and dimethylformamide (20:2:1) as the mobile phase. Remove
plate and allow to air dry. Reveal as prescribed in Procedure I: any secondary spot obtained with
Solution 1, other than the main spot, is not more intense than that obtained in the chromatogram with
Solution 2.
corresponding reference chemical solution, operating under nitrogen atmosphere and reduced light.
Develop the chromatogram using, as mobile phase, a mixture of diethylamine and petroleum ether
with a boiling range 40 –60 ºC saturated with 2-phenoxyethanol (2:100). Remove plate from the
chamber and allow to air dry. Examine under ultraviolet light with maximum intensity at 366 nm:
fluorescence is observed, produced in a few minutes. Then nebulize chromatoplate with 10% (v/v)
sulfuric acid solution in ethyl alcohol. The main stain in the chromatogram, obtained with Solution 1,
corresponds in position, color and fluorescence intensity to that obtained in the chromatogram with
Solution 2 and has the same stability for a period of minimum 20 minutes after nebulization.
Proceed as described in Thin Layer Chromatography (5.2.17.1), using silica-gel GF254 as support,
operating in a nitrogen atmosphere and protected from light. Prepare solutions, using a mixture of
methyl alcohol and diethylamine (95:5) with solvent: Solution (1): 2.0% sample solution (w/v) and
Solution (2): 0.01% sample solution (w/v). Apply separately to chromatoplate 10 μL of each fresh-
prepared solution. Develop chromatogram using the mobile phase specified in the monograph up to
12 cm above application point. Remove plate and allow to air dry. Examine under ultraviolet light (
254 nm). Discard any stain over the baseline. Any secondary stain obtained in the chromatogram with
Solution (1), except the main spot, is not more intense than the stain obtained with Solution (2), unless
monograph establishes differently.
Mobile phases:
A – Mixture of cyclohexane, acetone and diethylamine (80:10:10).
B – Mixture of hexane, acetone and diethylamine (85:10:5).
C – Mixture of butyl alcohol and M ammonium hydroxide (15:3).
Fixing the volume of standard solution at 1 mL, m (sample mass in g) can be calculated using the
formula:
354,6
𝑚=
𝑙
Standard preparation: Transfer the volume of standard hydrochloric acid (0.01 M HCl VS), indicated
in the monograph, in Table 1, or calculated, and a volume of 30 to 40 mL of distilled water, to a
Nessler tube.
Procedure: Transfer 1 mL of nitric acid RS to the Nessler tubes containing standard preparation and
sample preparation. If, after acidification, preparation is not perfectly clear, filter through a chloride-
free filter paper, transfer filtrate and 1 mL of 0.1 M silver nitrate to Nessler tube. Adjust volume to
50 mL with distilled water and homogenize. Allow to stand for five minutes protected from light.
Turbidity of sample preparation must not be greater than that of standard preparation.
Table 1 – Chloride impurity limits and corresponding quantities of raw material to carry out the test
-4
considering constant use of 1.0 mL of standard solution containing 3.546 x 10 g of chloride.
Sample quantity Chloride limit Sample quantity Chloride limit
(g) (ppm) (g) (ppm)
0.10 3546 (= 0.355%) 3.8 93
0.15 2364 (=0.236%) 4.0 88
0.20 1773 (=0.180%) 4.2 84
0.25 1418 (= 0.l42%) 4.4 80
0.30 1182 (=0.120%) 4.6 77
0.35 1013 (=0.100%) 4.8 74
0.40 886 5.0 71
0.45 788 5.2 68
0.50 709 5.4 65
0.55 645 5.6 63
0.60 591 5.8 61
0.65 545 6.0 59
0.70 506 6.2 57
0.75 473 6.4 55
0.80 443 6.6 53
The amount of chloride (3.546 x 10-4 g) in standard preparation being fixed, if chloride limit in a
given substance is, for example, 354 ppm, 1.0 g of the substance should be used to obtain up to the
same standard turbidity; if limit is 71 ppm of chloride, 5.0 g of sample should be used, and so on.
1200,8
𝑚=
𝑙
Standard preparation: Transfer the volume of standard sulfuric acid (0,005 M H2SO4 VS), indicated
in the monograph, in Table 2, or calculated, and a volume of 30 to 40 mL of distilled water, to a
Nessler tube.
Table 2 – – Sulfate impurity limits and corresponding quantities of raw material to carry out the test
considering the constant use of 2.5 mL of standard solution containing 1.2008 x 10 -3 g of sulfate.
Sample quantity Sulfate limit Sample quantity Sulfate limit
(g) (ppm) (g) (ppm)
0.50 2401 (=0.240%) 4.6 261
0.55 2183 (=0.220%) 4.8 250
0.60 2001 (=0.200%) 5.0 240
0.65 1847 (=0.185%) 5.2 231
0.70 1715 (=0.171%) 5.4 222
0.75 1601 (=0.160%) 5.6 214
0.80 1501 (=0.150%) 5.8 207
0.85 1412 (=0.141%) 6.0 200
0.90 1334 (=0.133%) 6.2 194
0.95 1264 (=0.126%) 6.4 187
1.00 1200 (=0.120%) 6.6 182
1.2 1001 (=0.100%) 6.8 177
1.4 858 7.0 171
1.6 750 7.2 166
1.8 667 7.4 162
2.0 600 7.6 158
2.2 546 7.8 154
2.4 500 8.0 151
2.6 462 8.2 146
2.8 429 8.4 143
3.0 400 8.6 139
3.2 375 8.8 136
3.4 353 9.0 133
3.6 333 9.2 130
3.8 316 9.4 127
4.0 300 9.6 125
4.2 286 9.8 122
4.4 273 10.0 120
Sulfate amount being fixed (1.2008 x 10-3 g), if sulfate limit in a given substance is, for example, 500
ppm, 2.4 g of sample should be used to obtain up to the same standard turbidity; if limit is 151 ppm
of sulfate, 8 g of sample should be used, and so on.
Determination of heavy metals can be carried out by two methods: limit test by formation of solid
sulfide particles or determination by atomic spectrometry.
Limit test consists of the formation of solid particles of heavy metal sulfides, in suspension, and
subsequent visual comparison of the color intensity in sample and standard preparations in a Nessler
tube. The test is semi-quantitative and makes it possible to infer whether sample passes the test or
not, representing the sum of the concentration of contaminating elements in the sample.
Atomic spectrometry method enables to quantify each contaminating element in the sample and
differentiated limits are established for each element according to its toxicity, pharmaceutical
preparation and route of administration. Elements such as As, Cd, Pb and Hg, due to their high
toxicity, have lower limits than the others. Due to the greater bioavailability of elements eventually
present in substances used in the manufacture of parenteral products, the specified limits are lower
than those related to oral use.
Special Reagents
Lead Nitrate Stock Solution: Accurately dissolve 159.8 mg of lead nitrate in 100mL of water and
1mL of nitric acid. Dilute with water to 1000 mL and homogenize. Prepare and store this solution in
glass containers free from soluble lead salts.
Standard lead solution (10 ppm Pb): dilute 10 mL of lead nitrate stock solution to 100 mL with water.
Each milliliter of this fresh-prepared solution contains the equivalent of 10 µg of lead (10 ppm Pb).
Preparation of thioacetamide reagent: see thioacetamide RS. Heat in water bath for 20 seconds, cool
and use immediately.
METHOD I
Sample preparation: transfer to a suitable tube sample solution prepared as specified in the
monograph and dilute to 25 mL with water, or dissolve and dilute with water to 25 mL the sample
amount, in g, specified in the monograph or calculated according to the formula:
2 / (1000l)
where
l = limit of heavy metals in sample in percentage (w/w).
Adjust pH between 3.0 and 4.0 with M acetic acid or 6 M ammonium hydroxide using narrow range
indicator paper as external indicator. Dilute with water to 40 mL and homogenize.
Standard preparation: transfer 2 mL of standard lead solution (10 ppm Pb) to a suitable tube and
dilute to 25 mL with water. Adjust pH between 3.0 and 4.0 with M acetic acid or 6 M ammonium
hydroxide using narrow range indicator paper as external indicator. Dilute with water to 40 mL and
homogenize.
Control preparation: transfer to a third tube volume of sample solution prepared as described in the
monograph or in sample preparation and 2 mL of standard lead solution (10 ppm Pb). Adjust pH
between 3.0 and 4.0 with M acetic acid or 6 M ammonium hydroxide using narrow range indicator
paper as external indicator. Dilute with water to 40 mL and homogenize.
Procedure: for each preparation, transfer 2 mL of acetate buffer pH 3.5 and 1.2 mL of thioacetamide
RS. Dilute with water to 50 mL, homogenize and allow to stand for two minutes. After two minutes,
a shade ranging from yellow to black will be produced. Observe preparations from top to bottom,
along the tube vertical axis, on a white background. The color produced in the sample preparation
must not be more intense than in the standard preparation. Test is only valid if intensity of the color
produced in the control preparation is equal to or greater than that of the standard preparation.
METHOD II
Sample preparation: transfer to a suitable tube the sample solution prepared as specified in the
monograph and dilute to 25 mL with organic solvent (dioxane or acetone, containing not less than
15% v/v of water), or dissolve and dilute with the same solvent for 25 mL the sample amount, in g,
specified in the monograph or calculated according to the formula:
2 / (1000l)
where
l = limit of heavy metals in sample in percentage (w/w).
Adjust pH between 3.0 and 4.0 with M acetic acid or 6 M ammonium hydroxide using narrow range
indicator paper as external indicator. Dilute with water to 40 mL and homogenize.
Standard preparation: transfer 2 mL of standard lead solution (10 ppm Pb) to a suitable tube and
dilute to 25 mL with the same solvent used to dissolve sample. Adjust pH between 3.0 and 4.0 with
M acetic acid or 6 M ammonium hydroxide using narrow range indicator paper as external indicator.
Dilute with the same solvent used to dissolve sample to approximately 40 mL and homogenize.
Control preparation: transfer to a third tube volume of sample solution prepared as described in the
monograph or in sample preparation and 2 mL of standard lead solution (10 ppm Pb). Adjust pH
between 3.0 and 4.0 with M acetic acid or 6 M ammonium hydroxide using narrow range indicator
paper as external indicator. Dilute with the same solvent used to dissolve sample to approximately
40 mL and homogenize.
Procedure: for each preparation, transfer 2 mL of acetate buffer pH 3.5 and 1.2 mL of thioacetamide.
Dilute with water to 50 mL, homogenize and allow to stand for two minutes. After two minutes, a
color ranging from yellow to black will be produced. Observe preparations from top to bottom, along
the tube vertical axis, on a white background. The color produced in the sample preparation must not
be more intense than in the standard preparation. The test is only valid if intensity of the color
produced in the control preparation is equal to or greater than that of the standard preparation.
METHOD III
Sample preparation: use sample amount, in g, specified in the monograph or calculated according to
the formula:
2 / (1000l)
where
l = limit of heavy metals in sample in percentage (w/w).
Transfer sample to a suitable crucible, with enough sulfuric acid to moisten the substance, and
carefully incinerate at low temperature. Transfer 2 mL of nitric acid and five drops of sulfuric acid to
the carbonized mass. Heat, carefully, until no more white vapors are released. Incinerate in muffle
furnace at 500 –600 ºC until carbon is completely combusted.
Cool at room temperature, add 4 mL of 6 M hydrochloric acid, cover, digest in water bath for 15
minutes, uncover and slowly evaporate in water bath until dry. Moisten residue with a drop of
hydrochloric acid, 10 mL of hot water and digest in water bath for two minutes. Make litmus paper
alkaline with 6 M ammonium hydroxide added dropwise. Dilute with water to 25 mL and adjust pH
between 3.0 and 4,0 with M acetic acid, using narrow range indicator paper as external indicator.
Filter if necessary, wash crucible and filter with 10 mL of water and combine filtrate and washing
water in a suitable tube for color comparison. Dilute with water to 40 mL and homogenize.
Standard preparation: transfer 2 mL of standard lead solution (10 ppm Pb) to a suitable tube and
dilute to 25 mL with the same solvent used to dissolve sample. Adjust pH between 3.0 and 4.0 with
M acetic acid or 6 M ammonium hydroxide using narrow range indicator paper as external indicator.
Dilute with the same solvent used to dissolve sample to approximately 40 mL and homogenize.
Control preparation: transfer to a third tube volume of sample solution prepared as described in the
monograph or in sample preparation and 2 mL of standard lead solution (10 ppm Pb). Adjust pH
between 3.0 and 4.0 with M acetic acid or 6 M ammonium hydroxide using narrow range indicator
paper as external indicator. Dilute with the same solvent used to dissolve sample to approximately
40 mL and homogenize.
Procedure: for each preparation, transfer 2 mL of acetate buffer pH 3.5 and 1.2 mL of thioacetamide.
Dilute with water to 50 mL, homogenize and allow to stand for two minutes. After two minutes, a
color ranging from yellow to black will be produced. Observe preparations from top to bottom, along
the tube vertical axis, on a white background. The color produced in the sample preparation must not
be more intense than that in the standard preparation. The test is only valid if intensity of the color
produced in the control preparation is equal to or greater than that of the standard preparation.
METHOD IV
Sample preparation: accurately weigh sample amount specified in the monograph or calculated
according to the formula:
2 / (1000l)
where
l = limit of heavy metals in sample in percentage (w/w).
Transfer to a 100 mL borosilicate glass digestion tube with about 10 mL nitric acid. Proceed with the
digestion on a heating plate or block digester at a temperature of 120°C, for three hours. It is
recommended to heat the system slowly to avoid sample projection. If acid evaporates, add another
5 mL aliquot. If a clear preparation is not obtained, add, after cooling, 2 mL of 30% hydrogen
peroxide (w/w) and heat at 140 °C for another hour. Cool and dilute cautiously with a small volume
of water. Transfer, with washing, to a 50 mL Nessler tube, without exceeding 25 mL.
Standard preparation: transfer 2 mL of standard lead solution (10 ppm Pb) to a suitable tube and
dilute to 25 mL with water. Adjust pH between 3.0 and 4.0 with M acetic acid or 6 M ammonium
hydroxide using narrow range indicator paper as external indicator. Dilute with water to 40 mL and
homogenize.
Control preparation: transfer to a third tube volume of sample solution prepared as described in the
monograph or in sample preparation and add 2 mL of standard lead solution (10 ppm Pb). Adjust pH
between 3.0 and 4.0 with M acetic acid or 6 M ammonium hydroxide using narrow range indicator
paper as external indicator. Dilute with water to 40 mL and homogenize.
Procedure: for each preparation, transfer 2 mL of acetate buffer pH 3.5 and 1.2 mL of thioacetamide.
Dilute with water to 50 mL, homogenize and allow to stand for two minutes. After two minutes, a
color ranging from yellow to black will be produced. Observe preparations from top to bottom, along
the tube vertical axis, on a white background. The color produced in the sample preparation must not
be more intense than in the standard preparation. The test is only valid if intensity of the color
produced in the control preparation is equal to or greater than that of the standard preparation.
METHOD V
Sample preparation: in cases where the previous sample preparation methods are not efficient,
proceed as described in Wet decomposition in closed system or Method of microwave-assisted
combustion in pressurized system described in Atomic spectrometry method.
Standard preparation: transfer 2 mL of standard lead solution (10 ppm Pb) to a suitable tube and
dilute to 25 mL with water. Adjust pH between 3.0 and 4.0 with M acetic acid or 6 M ammonium
hydroxide using narrow range indicator paper as external indicator. Dilute with water to 40 mL and
homogenize.
Control preparation: transfer to a third tube volume of sample solution prepared as described in the
monograph or in sample preparation and 2 mL of standard lead solution (10 ppm Pb). Adjust pH
between 3.0 and 4.0 with M acetic acid or 6 M ammonium hydroxide using narrow range indicator
paper as external indicator. Dilute with water to 40 mL and homogenize.
Procedure: for each preparation, transfer 2 mL of acetate buffer pH 3.5 and 1.2 mL of thioacetamide.
Dilute with water to 50 mL, homogenize and allow to stand for two minutes. After two minutes, a
color ranging from yellow to black will be produced. Observe preparations from top to bottom, along
the tube vertical axis, on a white background. The color produced in the sample preparation must not
be more intense than that in the standard preparation. The test is only valid if intensity of the color
produced in the control preparation is equal to or greater than that of the standard preparation.
Use atomic spectrometry methods to determine As, Cd, Cr, Cu, Hg, Ir, Mn, Mo, Ni, Os, Pb, Pd, Pt,
Rh, Ru and V, according to Atomic spectrometry (5.2.13). However, different sample preparation
procedures can be applied, as shown in Figure 1.
Yes
Yes
In water-soluble substances, there is no need to decompose the sample beforehand, it can be analyzed
directly after dissolution. If it is not soluble in water and presents solubility in another solvent, the
substance can be analyzed directly after dissolution if there is no incompatibility between solvent and
the atomic spectrometry method used. When none of the above conditions are met, it is recommended
to decompose the sample beforehand. In these cases, two procedures are recommended:
Accurately weigh the amount of sample between 0.1 and 0.5 g of sample and add nitric acid as
recommended by the manufacturer and proceed with digestion in closed system with conventional
heating or microwave at temperature of 180 °C or higher. In systems that use conventional heating
and microwaves, when there is no specification in the monograph, it is recommended to digest for
240 minutes and 20 minutes, respectively.
In principle, the two decomposition procedures described can be used interchangeably. However, the
use of wet decomposition is recommended due to its higher simplicity and sample processing
capacity. Other reagents such as hydrochloric acid, sulfuric acid, hydrogen peroxide and hydrofluoric
acid (cannot be used in quartz flasks) can also be used in the digestion step, depending on the need.
Decomposition by microwave-assisted combustion is recommended in cases where wet digestion is
not efficient for organic samples.
The maximum allowed limits for each element are described in Table 1.
Iron Standard Solution (10 ppm Fe): dilute 10 mL of Iron Standard Solution (100 ppm Fe) with
distilled water and adjust to 100 mL.
Iron Standard Solution (2 ppm Fe): dilute 2 mL of Iron Standard Solution (100 ppm Fe) with distilled
water and adjust to 100 mL.
METHOD I
Sample preparation: weigh the sample amount specified in the monograph, or in Table 1, or
calculated, dissolve in a suitable solvent, transfer to a Nessler tube (capacity of 50 mL and 22 mm
internal diameter). Add distilled water, or the solvent indicated in the monograph, in an amount
sufficient for 40 mL. Add 2 mL of 20% citric acid (w/v).
Fixing the volume of Iron standard solution (100 ppm Fe) in 1 mL, the value of m (sample mass in g)
can be calculated using the formula:
100
𝑚=
𝑙
Standard preparation: use 10 mL of Iron Standard Solution (10 ppm Fe) or 1 mL of Iron Standard
Solution (100 ppm Fe), according to Table 1, or calculated volume, and add distilled water, or the
solvent indicated in the monograph , in sufficient quantity for 40 mL. Add 2 mL of 20% citric acid
(w/v).
Procedure: at the same time, add two drops of thioglycolic acid to the tubes containing the sample
and standard preparations. Homogenize, make alkaline with ammonium hydroxide, adjust to 50 mL
with distilled water and homogenize. Allow to stand for five minutes. The pink color produced in the
sample preparation should not be more intense than in the standard preparation.
METHOD II
Sample preparation: weigh sample quantity specified in the monograph, or calculated, dissolve in
suitable solvent, or use volume of sample solution as specified in the monograph. Transfer 2 mL of 2
M hydrochloric acid and 0.5 mL of bromine water RS. After five minutes, remove bromine excess by
air current in a fume hood (CAUTION!) TOXIC REAGENT) and transfer to a Nessler tube (50 mL
capacity and 22 mm internal diameter).
Standard preparation: submit the volume of Iron Standard Solution (2 ppm or 10 ppm Fe) indicated
in the monograph, or the calculated volume, as described in the sample preparation.
Procedure: at the same time, add to the tubes containing the sample and standard preparations, 3 mL
of potassium thiocyanate M, complete the volume to 50 mL, homogenize and allow to stand for five
minutes. The color produced in the sample preparation must not be more intense than in the standard
preparation.
METHOD III
Sample preparation: transfer to a Nessler tube (50 mL capacity and 22mm internal diameter) the
amount of sample specified in the monograph, or calculated, or the volume of sample solution
indicated in the monograph. Dilute to 40 mL with distilled water. Add 2 mL of M hydrochloric acid
and homogenize.
Standard preparation: transfer the volume of Iron Standard Solution (10 ppm Fe) indicated in the
monograph, or calculated volume, to a Nessler tube and proceed as described in the sample
preparation.
Procedure: transfer 50mg of ammonium peroxydisulfate crystals to the tubes containing sample and
standard preparations. Add 3 mL of ammonium thiocyanate RS, adjust to 50 mL with distilled water
and homogenize. The color produced in the sample preparation must not be more intense than in the
standard preparation.
Table 1 – Limits of iron impurity and corresponding amount of raw material to carry out the test considering
-4
the constant use of 1.0 mL of the iron standard 100 ppm solution, which contains 10 g of iron, in the standard
preparation.
Sample quantity Iron limit Sample quantity Iron limit
(g) (ppm) (g) (ppm)
0.100 1000 0.4 250
0.105 950 0.5 200
0.111 900 0.667 150
0.116 850 1 100
0.125 800 1.111 90
0.133 750 1.250 80
0.143 700 1.429 70
0.154 650 1.667 60
0.167 600 2 50
0.182 550 2.5 40
0.200 500 3.333 30
0.222 450 5 20
0.250 400 10 10
The amount of iron (10-4 g of Fe) in the Standard Preparation being fixed, if the limit of iron in a
given substance is, for example, 1000 ppm, 0.1 deg of sample should be used to obtain the same
coloration of the standard preparation; if the limit is 200 ppm iron, 0.5 g of sample should be used,
and so on.
METHOD IV
Alternatively, for iron determination, proceed with the preparation of the sample solution as described
in Limit test for heavy metals (5.3.2.3) and carry out the determination by one of the Atomic
spectrometry methods (5.2.13).
The method is based on the reaction between arsine (AsH3) released and silver diethyldithiocarbamate
that form a red complex; radiation absorption can be measured in a spectrophotometer or colorimeter.
Two methods can be used, differing only in sample and standard preparation. Method I is generally
used for inorganic substances, whereas Method II is used for organic substances.
The system used – Figure 1 – comprises: (a) arsine generator; (b) and (d) together; (c) ground unit;
(e) absorption tube. Another adapted system that has the essential characteristics of the presented one
can, eventually, be used.
Arsenic standard stock solution: dry arsenic trioxide for one hour at 105 °C. Accurately weigh 132mg
and dissolve in 5mL of sodium hydroxide solution (1:5) in a 1000mL volumetric flask. Neutralize
with M sulfuric acid and then add another 10 mL of M sulfuric acid. Adjust volume with freshly
boiled and cooled water.
Arsenic standard solution: transfer 1 mL (or 0.5; or 0.25; or 0.1 mL) of the arsenic standard stock
solution to a 100 mL (or 50, or 25, or 10 volumetric flask) mL, as required by the laboratory) –
Preserve the environment. Add 1 mL of M sulfuric acid and complete the volume with freshly boiled
water and, subsequently, cooled. Homogenize. Store the solution in a glass container and use within
three days. Each mL of the solution obtained contains 1 µg of arsenic.
METHOD I
Sample preparation: transfer to the arsine generator flask the amount of substance indicated in the
monograph, or the calculated amount. Fixing the volume of the standard arsenic solution at 3 mL, m
(mass in g of the sample) can be calculated using the formula:
3
𝑚=
𝑙
Dissolve with distilled water, adjusting the volume to 35 mL. Transfer 20 mL of sulfuric acid M, 2
mL of potassium iodide RS, 0.5 mL of strongly acidic stannous chloride RS and 1 mL of isopropyl
alcohol. Homogenize. Allow to stand for 30 minutes at room temperature. In unit (c) of the device
described, place two pieces of cotton soaked in a saturated solution of lead acetate, leaving a space
of 2mm between them. Solution excess must be eliminated by squeezing the cotton pieces and drying
them under reduced pressure at room temperature. The joints (b) and (d) must be lubricated with
petroleum jelly and joined as in Figure 1.
Standard preparation: transfer 3 mL of Arsenic Standard Solution to the arsine generator vial. Dilute
with distilled water to 35 mL. Proceed in the same manner as described for sample preparation.
METHOD II
This method additionally employs hydrogen peroxide in sample digestion. With certain substances it
can cause a violent reaction. Therefore, it is important to proceed carefully at all stages. Caution must
also be taken in the presence of halogenated compounds, especially when heating the sample with
sulfuric acid and subsequently adding 26% hydrogen peroxide (v/v). Heating should be gentler
preventing it from reaching the boiling temperature of the mixture and charring to prevent arsenic
loss.
Sample preparation: transfer to the generator flask the quantity of sample specified in the monograph,
or calculated. Fixing the volume of the standard arsenic solution at 3 mL, m (mass in g of the sample)
can be calculated using the formula:
3
𝑚=
𝑙
Add 5 mL of sulfuric acid and glass beads. If necessary, use a larger amount of acid to completely
moisten the substance, taking care that the volume does not exceed 10 mL. Proceed with the digestion
in fume hood, preferably using a hotplate with a temperature not exceeding 120°C for the time
necessary to start the digestion. Once sample decomposition begins, add dropwise and carefully
concentrated hydrogen peroxide. Wait for the reaction to slow down and then heat between addition
of each drop. If there is foam excess, stop heating. As soon as the reaction intensity decreases, heat it
carefully with flask shaking to promote homogeneous heating. It is necessary to maintain the
oxidizing conditions throughout digestion. To do this, add small amounts of concentrated hydrogen
peroxide whenever the mixture turns brown or darkens. Once the organic matter is destroyed,
gradually increase the heating temperature allowing the sulfur trioxide vapors to be released and the
solution to become colorless or slightly beige. Cool, carefully add 10 mL of distilled water, evaporate
until the sulfur trioxide is again released and cool. If necessary, repeat the operation, removing traces
of hydrogen peroxide. Cool and add 10 mL of distilled water. Wash the flask and dilute with distilled
water, bringing the volume to 35 mL. Proceed as in the sample preparation of Method I starting with
“Transfer 20 mL of sulfuric acid M...”.
Note: antimony interferes with the reaction, as it forms stibine (SbH 3) providing a falsely positive
result in color development with silver diethyldithiocarbamate RS. In these cases, the preparations
at wavelengths of 535 and 540 nm should be compared, in which the interference of the stibine is
negligible.
Proceed with sample preparation as described in item Wet decomposition in a closed system – Limit
test for heavy metals (5.3.2.3) and determine by Atomic absorption spectrometry with hydride
generation (5.2.13.1.2). Proceed according to manufacturer specifications using a wavelength of
193.7 nm and monochromator resolution of (0.5 ±0.1) nm.
Proceed with sample preparation as described in item Wet decomposition in a closed system – Limit
test for Heavy Metals (5.3.2.3) and determine by Inductively coupled plasma optical emission
spectrometry (5.2.13.2.2). Proceed according to manufacturer’s specifications. It is recommended to
use the wavelength of 188.979 to 189.042 nm.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.2-01
Ammonia standard solution (1 ppm NH 3 ): dilute 40 mL of ammonia standard solution (2.5 ppm NH
3) to 100 mL with distilled water.
Sample preparation: dissolve the indicated amount of the test substance in 12 mL of distilled water,
make alkaline, if necessary, with 2 M sodium hydroxide. Transfer to a 15 mL volumetric flask, add
0.3 mL of alkaline potassium tetraiodomercurate (II) solution and adjust volume with distilled water.
Homogenize and allow to stand for five minutes. Transfer to a Nessler tube with a capacity of 50 mL
and an internal diameter of 22 mm.
Standard preparation: transfer 10 mL of ammonia standard solution (1 ppm NH 3), or the calculated
volume, to a 15 mL volumetric flask, add 4.0 mL of distilled water, 0.3 mL of alkaline
tetraiodomercurate solution ( II) potassium and adjust volume with distilled water. Homogenize and
allow to stand for five minutes. Transfer to a Nessler tube.
Procedure: compare the color produced in the preparations. The yellow color produced in the sample
preparation must not be more intense than in the standard preparation.
Calcium Standard solution (10 ppm Ca): accurately weigh 0.624 g of calcium carbonate and transfer
to a 250 mL volumetric flask with 3 mL of acetic acid. Dissolve and complete the volume with
distilled water. Immediately before use, transfer 10 mL of this solution to a 1000 mL volumetric flask
and complete the volume with water.
Sample preparation: transfer 1 mL of ammonium oxalate RS to a Nessler tube (50 mL capacity and
22 mm internal diameter) containing 0.2 mL of the calcium standard solution alcoholic(100 ppm Ca).
Wait one minute, add a mixture of 1 mL of diluted acetic acid and 15 mL of the sample solution
prepared as described in the monograph.
Standard preparation: transfer to a Nessler tube the same amounts of ammonium oxalate RS and the
standard calcium solution alcoholic (100 ppm Ca) as per sample preparation. Wait one minute, add a
mixture of 10 mL of the calcium standard solution (10 ppm Ca), 1 mL of diluted acetic acid and 5
mL of distilled water.
Procedure: homogenize the preparations in Nessler tubes. After 15 minutes, the turbidity of the
sample preparation should not be more intense than that of the standard preparation.
Alternatively, proceed with the sample preparation as indicated in the monograph and carry out the
determination of calcium by Flame atomic absorption spectrometry (5.2.13.1.1) using an aracetylene
type flame, wavelength of 422.7 42nm and resolution of the monochromator of (0.7 ± 0.1) nm; or
Inductively Coupled Plasma Optical Emission Spectrometry (5.2.13.2.2) using the wavelength of
393.366 nm.
Procedure: Transfer the sample preparation to a separating funnel and extract twice, shaking for one
minute each time, with 5 mL of a 0.1% (w/v) solution of hydroxyquinoline in chloroform. Discard
the organic phases and transfer 0.4 mL of butylamine and 0.1 mL of triethanolamine to the aqueous
phase. Adjust pH between 10.5 to 11.5 if necessary. Add 4 mL of 0.1% (w/v) hydroxyquinoline
solution in chloroform and shake for one minute. Use the lower phase for comparison. Proceed in the
same manner with the standard preparation. The color produced in the sample preparation must not
be more intense than in the standard preparation.
Aluminum Standard Solution (10 ppm Al): transfer, immediately before use, 5 mL of Aluminum
Standard Solution (200 ppm Al) to a 100 mL volumetric flask; adjust volume with distilled water and
homogenize.
Aluminum Standard Solution (2 ppm Al): transfer, immediately before use, 1 mL of Aluminum
Standard Solution (200 ppm Al) to a 100 mL volumetric flask; adjust volume with distilled water and
homogenize.
Nitric acid diluent solution: transfer 40 mL of nitric acid to a 1000 mL volumetric flask; adjust
volume with distilled water and homogenize.
METHOD I
Sample preparation: use the specified amount of the sample, or calculated, prepared as specified in
the monograph.
Standard Preparation: Use the specified or calculated volume of Aluminum Standard Solution (10
ppm or 2 ppm).
Procedure: transfer the sample and standard preparations to separating funnels and extract with three
portions (20, 20 and 10 mL) of the 0.5% (w/v) hydroxyquinoline solution in chloroform. Add the
chloroform extracts and dilute to 50 mL with chloroform. Carry out a blank preparation using the
same solvent. Measure the fluorescence intensity (5.2.15) of the sample preparation (I1), the standard
preparation (I2) and the blank preparation (I3) using an excitation wavelength of 392 nm and
monochromator set at 518 nm. The fluorescence of the sample preparation (I1), deducted from the
blank preparation (I3) must not be greater than that of the standard preparation (I2), deducted from
the blank preparation (I3).
METHOD II
Sample preparation: transfer the quantity of the sample specified in the monograph, or calculated,
and 50 mL of distilled water to a 100 mL plastic volumetric flask and submit to an ultrasonic bath for
30 minutes. Add 4 mL of nitric acid; adjust volume with distilled water and homogenize.
Standard preparations: prepare solutions containing 0.01, 0.02 and 0.04 ppm of aluminum,
immediately before use, by diluting the Aluminum Standard Solution (1 ppm Al) with Nitric Acid
Diluent Solution in a 100 mL volumetric flask.
Procedure: determine the absorbances of the standard preparations and the sample preparation by
Graphite furnace atomic absorption spectrometry (5.2.13.1.4) equipped with a hollow aluminum
cathode lamp. Adjust the wavelength to 309.3 nm using a monochromator resolution of
(0.7 ±0.1) nm. Use the Nitric Acid Diluent Solution as a blank and proceed with the calibration as
described in (5.2.13.1.4) Method I (Direct Calibration). Determine the Al concentration in the sample
preparation in ppm. Calculate the amount of Al in the sample in ppm by multiplying the concentration
of the sample preparation in ppm by 100/P where P is the mass in g of the substance used in the
sample preparation.
METHOD III
Proceed as described in Method II and carry out the determination by Optical Emission Spectrometry
with Inductively Coupled Plasma (5.2.13.2.2). Proceed according to manufacturer’s specifications. It
is recommended to use the wavelength of 396.153 nm.
Phosphate standard solution (5 ppm): dissolve 0.716 g of monobasic potassium phosphate in distilled
water and adjust to 1000 mL. Transfer 10 mL of this solution to a 1000-mL volumetric flask and
adjust the volume with distilled water.
Sample preparation: transfer the specified, calculated amount of sample or the volume of sample
solution prepared as described in the monograph to a 100 mL volumetric flask and adjust volume
with the appropriate solvent. Transfer this solution, 4 mL of sulfomolybdic reagent, 0.1 mL of
stannous chloride RS to a beaker and homogenize.
Procedure: wait 10 minutes, transfer 20 mL of the contents of the sample and standard preparations
to Nessler tubes (capacity of 50 mL and 22 mL of internal diameter) and compare the color of the
preparations. The color produced in the sample preparation must not be more intense than in the
standard preparation.
Note: Store all reagent solutions in borosilicate glass containers. Rinse the entire glassware with a
20% (v/v) nitric acid solution and then with distilled water.
Sample preparation: in the absence of specification in the monograph, prepare the sample solution
as follows. Proceed in a fume hood, as some substances can react violently when digested with
hydrogen peroxide. Transfer 1.0 g of the sample to a suitable flask, add 5 mL of sulfuric acid, some
glass beads and heat in a hotplate, in a hood, until the fumes evolve. Other suitable means of heating
can be used. If necessary, add excess sulfuric acid to completely wet the sample not exceeding a total
of 10 mL. Carefully add dropwise concentrated hydrogen peroxide, heating between additions,
allowing the reaction to take place. Add the first drops slowly and very slowly, mixing carefully to
prevent rapid reaction and stopping heating if excessive foaming occurs. Shake the solution in the
vial to allow the sample adhering to the walls to react. Add hydrogen peroxide whenever the mixture
turns brown or darkens. Continue digestion until sulfur trioxide vapors are released abundantly so
that the reaction is complete and the solution becomes colorless. Cool, cautiously, with the addition
of 10 mL of distilled water, evaporate again until the sulfur trioxide is fully released and cool. Repeat
this procedure with 10 mL of distilled water to remove any traces of hydrogen peroxide. Carefully
dilute with 10 mL of distilled water and cool.
Note: if, before heating, the sample reacts very quickly and starts to smoke with 5 mL of sulfuric acid,
use 10 mL of cold 50% sulfuric acid (v/v) and add a few drops of peroxide hydrogen before heating.
Standard Preparation: Use the specified or calculated volume of Lead diluted standard solution (1
ppm Pb). Subject to the same treatment as the sample preparation.
Procedure: Transfer the Sample Preparation and Standard Preparation to a separating funnel using
10 mL of distilled water. Add 6 mL of ammonium citrate RS and 2 mL of hydroxylamine
hydrochloride RS1 (for the determination of lead in iron salts use 10 mL of ammonium citrate RS).
Add two drops of 0.1% phenol red (w/v) in ethyl alcohol, make alkaline with ammonium hydroxide
until red color and homogenize. Cool the solution, if necessary, and add 2 mL of potassium cyanide
RS. Immediately extract with 5 mL portions of the dithizone extraction solution and collect each
extract into another separating funnel until the dithizone solution maintains its green color. Shake the
combined dithizone solutions for 30 seconds with 20 mL of 1% nitric acid (v/v) and discard the
organic phase. Transfer 5 mL of dithizone standard solution and 4 mL of cyanide ammonia RS to the
acid solution and shake for 30 seconds. The violet color produced in the organic phase of sample
preparation must not be more intense than in the standard preparation.
Alternatively, prepare the sample as described in Limit Test for Heavy Metals (5.3.2.3) and determine
lead by one of the Atomic Spectrometry methods (5.2.13).
Proceed as described in Gas chromatography (5.2.17.5). Use a gas chromatograph equipped with a
flame ionization detector; column of fused silica 25 m long and 0.32 mm internal diameter, covered
with a 0.52 µm thick cross-linked polymethylphenylsiloxane film, maintained at a temperature of
150°C for five minutes, then increase the temperature in the ratio of 20°C per minute to 275°C and
keep at this temperature for three minutes. The injector temperature should be 220 °C and the detector
300 °C. Use helium as carrier gas with a flow split ratio of 1:20, column head pressure of 50 kPa and
flow divider of 20 mL per minute. The flow divider jacket consists of a column approximately 1 cm
in length, filled with diatomaceous earth for gas chromatography impregnated with 10%
polydimethylsiloxane.
Sample Solution: Transfer approximately 0.50 g of accurately weighed sample to a centrifuge tube
and add 30 mL of water. Add 1.0 mL of Internal Standard Solution and adjust the solution
temperature between 26 and 28 °C. Add 1.0 mL of 10.5 M sodium hydroxide and shake until complete
dissolution. Add 2.0 mL of trimethylpentane. Shake for two minutes and wait for phase separation.
Use the clear supernatant solution.
Procedure: Separately inject equal volumes (approximately 1 µL) of Standard Solution and Sample
Solution into the chromatograph, record the chromatograms and main peak responses. Retention
times should be approximately 3.6 minutes for N,N-dimethylaniline and 5.0 minutes for N,N-
diethylaniline. The ratio between the peak responses of dimethylaniline and diethylaniline, obtained
from the Sample solution, must not be greater than that obtained from the Standard solution (0.002%).
METHOD II
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.2-01
Proceed as described in Gas chromatography (5.2.17.5). Use gas chromatograph equipped with a
flame ionization detector, a 2 m long and 2 mm internal diameter glass column, packed with a
silanized diatom support for gas chromatography impregnated with 3% polymethylphenylsiloxane,
kept at a temperature of 120°C and the temperature of the injector and detector at 150°C. Use nitrogen
as carrier gas (30 mL/minute flow).
Sample Solution: Transfer approximately 1.0 g of accurately weighed sample to a centrifuge tube and
add 5 mL of M sodium hydroxide until complete dissolution. Add 1.0 mL of the Internal standard
solution, shake vigorously for one minute and centrifuge. Use the clear supernatant solution.
Procedure: Separately inject equal volumes (approximately 1 µL) of Standard Solution and Sample
Solution into the chromatograph, record the chromatograms and main peak responses. The ratio
between the peak responses of dimethylaniline and naphthalene, obtained from the Sample solution,
must not be greater than that obtained from the Standard solution (0.002%).
In Method I, iodine starch solution or iodine starch paper is used as indicator. Excess nitrous acid
converts iodide to iodine, which in contact with starch results in the characteristic blue color.
In Method II, the titration endpoint is determined potentiometrically. In this method, platinum-
calomel or platinum-platinum electrodes with adequate potential difference and sensitivity are used.
After use, the electrodes should be immersed for a few seconds in nitric acid RS to which 1mg/mL
of ferric chloride was added and then wash with distilled water.
METHOD I
Procedure – Accurately weigh approximately 500mg of the sulfonamide or the amount specified in
the monograph for other primary aromatic amines and transfer to a 250 mL Erlenmeyer flask. Add,
while shaking, 100 mL of hydrochloric acid RS to dissolve the sample. Then add about 30 mL of
water and cool in ice bath to approximately 15 ºC. Titrate, under constant agitation, with a 0.1 M
sodium nitrite solution VS previously standardized with CRS sulfanilamide. The titration endpoint is
reached when a drop of the Erlenmeyer solution immediately turns blue with a iodine starch solution
TS on a spot plate or on moist iodine starch TS paper. To check the titration completion, repeat the
spot test two minutes after the last addition. This one should remain positive.
The weight, in mg, of the sample corresponding to each mL of 0.1 M sodium nitrite VS is described
in the monograph of each drug.
METHOD II
Procedure – Accurately weigh approximately 500mg of the sulfonamide, or the equivalent in mass
of the active ingredient for pharmaceutical specialties, or the amount specified in the monograph for
other primary aromatic amines. In injectables or other liquid forms, an amount equivalent to 500 mg
of active ingredient or the amount specified in the monograph must be used. Transfer to an
Erlenmeyer flask and add 20 mL of hydrochloric acid RS and 50 mL of water. Shake until dissolved.
Cool to approximately 15°C maintaining this temperature over the course of the titration. Add suitable
catalyst when specified. Titrate, slowly and under constant agitation, with a 0.1 M sodium nitrite
solution VS previously standardized with CRS sulfanilamide.
The weight, in mg, of the sample corresponding to each mL of 0.1 M sodium nitrite VS is described
in the monograph of each drug.
Note: The tip of the burette must remain just above the surface of the solution to avoid oxidation of
the sodium nitrite. Shake carefully, avoiding the formation of a vortex of air below the surface. When
the titration is approximately 1 mL from the calculated endpoint, add 0.1 mL volumes at ranges of
not less than one minute.
In the presence of nitrates or nitrites, accurately transfer the weighed amount of the sample containing
about 150mg of nitrogen, 25 mL of sulfuric acid containing 1g of dissolved salicylic acid to a 500
mL Kjeldahl flask. Homogenize and wait for about 30 minutes shaking frequently. Add 5 g of sodium
thiosulfate, homogenize and then add 0.5 g of cupric sulfate. Proceed as indicated in the previous
procedure starting from “Lean the flask approximately 45°...”.
When the nitrogen content in the sample exceeds 10%, add, prior to digest, 0.5 to 1.0 g of benzoic
acid to facilitate the decomposition of the substance.
Distill until the volume of distillate reaches 80 to 100 mL; remove the collecting flask, wash the walls
with a small amount of water and titrate with 0.005 M sulfuric acid VS. Carry out blank test and make
the necessary corrections. Each mL of 0.005 M sulfuric acid VS is equivalent to 0.1401 mg of
nitrogen.
Apparatus
It comprises a conical flask made of resistant refractory borosilicate glass, with an internal volume of
500 mL and a ground glass cap. For determination of fluoride, a quartz flask is used. The base of the
ground cap that accompanies the flask has a glass extension on which a platinum wire is fixed with
an end composed of a platinum support where the sample is introduced (Figure 1).
Solid samples
Weigh the amount specified in the monograph onto a piece of filter paper of appropriate shape and
dimensions, fold and hold to the platinum mesh, leaving part of the edge free. Place the specified
absorber solution inside the flask and bubble oxygen into this solution to saturate the interior of the
flask. Ignite the end of the paper (see Note 1) and, without delay, place the cap on the flask, holding
it firmly in place to prevent its displacement due to the pressure exerted by the combustion gases.
Invert the flask to ensure liquid seal at the cap, taking care to prevent incompletely burnt material
from falling into the liquid. Once combustion is complete, shake the flask until the gases formed in
the process disappear. After 15 to 30 minutes, place a small amount of water on the rim of the flask
and remove the cap, allowing this water to flow into the flask, washing the neck walls. Wash stopper,
neck, wire and platinum mesh with water and transfer washing water to the absorbent solution. The
solution obtained by this procedure is called sample solution. To prepare the blank, proceed likewise,
omitting the sample (Note 2).
Liquid samples
Pack a small amount of absorbent cotton in a piece of filter paper and weigh, in this device, the
specified amount of the sample, which is absorbed into the cotton. After fixing the cotton wrapped in
the filter paper to the platinum mesh, proceed with combustion as described for solid samples.
Burn the specified amount of the substance under examination, using as an absorbent solution 20 mL
of water plus 1 mL of concentrated hydrogen peroxide and 3 mL of 0.1 M sodium hydroxide. After
absorption, add two drops of bromophenol blue and sufficient amount of 0.1 M nitric acid to turn the
indicator from blue to yellow, incorporating 0.5 mL of excess. If the test substance contains sulfur,
add a few drops of 0.005 M barium nitrate. Add 100 mL of ethyl alcohol, using the addition to wash
the inner walls of the flask, and then 15 drops of diphenylcarbazone TS. Titrate with 0.005 M mercury
(II) nitrate VS until permanent pink color. Each mL of 0.005 M mercury (II) nitrate VS is equivalent
to 0.3550 mg of chlorine or to 0.79904 mg of bromine.
Determination of iodine
Burn the specified amount of the substance under examination as described, using as an absorbent
liquid 10 mL of water plus 2 mL of M sodium hydroxide. After absorption, add 1 mL of 4 M hydrazine
hydrate solution in water, cap the flask again and shake until the solution is pale. Then proceed as
described in Determination of Chlorine and Bromine from “Once the absorption is completed...”.
Each mL of 0.005 M mercury (II) nitrate VS is equivalent to 1.269 mg of iodine.
Determination of fluorine
Burn the specified amount of the substance under examination as described, using 15 mL of water as
an absorbing solution. Once the operation is completed, wash the stopper, platinum wire, platinum
mesh and flask sides (Note 3) with 40 mL of water. Add 0.6 mL of alizarin TS and then add dropwise
0.1 M sodium hydroxide until the color changes from pink to yellow. Add 5 mL of acetate buffer
solution – hydrochloric acid pH 3.5 and titrate with 0.005 M thorium nitrate VS until yellow color
changes to pinkish yellow. Each mL of 0.005 M thorium nitrate VS is equivalent to 0.380 mg of
fluorine. If a difficulty arises when identifying the changeover, carry out a preliminary test with a
standardized inorganic fluorine solution.
Determination of sulfur
Burn the specified amount of the substance under examination as described, using 12.5 mL of
hydrogen peroxide RS as absorbing solution. Once the absorption is complete, add 40 mL of water,
using it to wash the stopper, platinum wire and mesh and the flask sides. Boil the solution for 10
minutes, cool, add 2 mL of acetic acid RS and 20 mL of ethyl alcohol. Titrate with 0.01 M barium
nitrate VS, using two drops of thorin TS and two drops of methylthioninium chloride TS as indicator
until the yellow color changes to pink. Each mL of 0.01 M barium nitrate VS is equivalent to 0.3206
g of sulfur.
Notes:
1. It is recommended that the analyst wear safety glasses and adequate protection to prevent vial
splinters from reaching her/him in the event of an accident. Currently, there are commercially systems
that avoid manual ignition, using infrared radiation or electric current, reducing the risks to the
operator.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.3-00
2. Ensure that combustion vials are clean and free from traces of organic solvents.
3. Substances containing fluorine provide low contents if combustion is carried out in borosilicate
glass vials. Satisfactory results are obtained in boron-free soda-glass flasks, but the ideal
performance implies the use of quartz flasks.
wick
sample wrapped in
filter paper
platinum mesh
absorbent solution
ground stopper
Apparatus
It comprises a quartz flask with an internal volume of 80 mL and an operating pressure of 80 atm.
The lid that comes with the flask is made of fluorinated polymer, which has an orifice to release gases
in case of wet decomposition, which is used to pressurize the system with oxygen. A quartz sample
holder is inserted inside the decomposition flask.
Solid samples
Weigh the specified amount of substance and press into tablet form (approximately 1.2 cm in
diameter). Place the sample on the quartz support containing a piece of filter paper (approximately
10mg) moistened with 6M ammonium nitrate. Place the specified absorbent solution inside the flask
and insert the holder containing the sample and paper into the flask. Close the system properly, as per
manufacturer’s specifications, and pressurize with 20 atm of oxygen. Insert the decomposition flasks
into the microwave oven rotor and, without delay, place the rotor in the oven cavity, immediately
starting irradiation. Once the ignition is started, using maximum power, the irradiation can be
continued for another five minutes, so that the reflux of the absorbent solution takes place, allowing
the complete absorption of the analytes in the solution. After cooling (20 minutes), the decomposition
flask can be opened and the solution transferred to an appropriate container with the aid of water and
measured to a known volume, for the subsequent identification or determination of the analytes of
interest. The solution obtained by this procedure is called sample solution. To prepare the blank,
proceed in the same manner, omitting the sample.
Proceed as described in “Determination of Chlorine and Bromine” in the Atmospheric Pressure Flask
Combustion Method.
Determination of iodine
Determination of fluorine
Determination of sulfur
Many complexants known as chelators are capable of forming cyclic structures through the
simultaneous coordination of several groups with the metallic ion. Edetic acid
(ethylenediaminetetraacetic acid, EDTA) is the typical example. This acid is the most used
complexing agent. EDTA forms 1:1 complexes with many metals with an oxidation state greater than
+1 and these complexes are highly soluble in water.
The stability of EDTA complexes is pH dependent for different metals. Therefore, ideal pH conditions
must be established for the complexation analysis for each metal.
PROCEDURES
Aluminum
Accurately weigh the amount of the substance indicated in the monograph, add 50 mL of water and
acidify, if necessary, with a minimum amount of hydrochloric acid M, unless the monograph indicates
another type of solvent. Add 25 mL of 0.1 M disodium edetate VS and 10 mL of the mixture, in equal
volumes, of 2 M ammonium acetate with 2 M acetic acid. Heat the solution to boiling and keep for
two minutes. Cool down. Add 50 mL of ethyl alcohol and 3 mL of fresh- prepared solution of 0.025%
(w/v) dithizone in ethyl alcohol. Titrate excess disodium edetate with 0.1 M zinc sulfate VS until the
color changes from blue-green to violet-pink. Each mL of 0.1 M disodium edetate VS is equivalent
to 2.698 mg of aluminum.
Bismuth
Accurately weigh the amount of the substance indicated in the monograph and dissolve in a minimum
amount of 2 M nitric acid. Add 50 mL of water and concentrated ammonia solution, drop by drop
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.3-00
while shaking, until the preparation becomes turbid. Add 0.5 mL of nitric acid and heat at 70 °C until
the turbidity of the preparation disappears. Add a few drops of xylenol orange TS. Titrate slowly with
0.05 M disodium edetate VS until color changes from pink-violet to yellow. Each mL of 0.05 M
disodium edetate VS is equivalent to 10.45 mg of bismuth.
Calcium
Accurately weigh the amount of the substance indicated in the monograph, dissolve in a few milliliters
of water and acidify, if required, with a minimum amount of 2 M hydrochloric acid. Dilute to 100 mL
with water. Titrate with 0.05 M disodium edetate VS to approximately 2 mL before predicted
equivalence point. Add 4 mL of 10 M sodium hydroxide and drops of chalcone TS. Continue titration
until the color changes from pink to deep blue. Each mL of 0.05 M disodium edetate VS is equivalent
to 2.004 mg of calcium.
Lead
Accurately weigh the amount of the substance indicated in the monograph and dissolve in 5 to 10 mL
of water, or in a minimum amount of 5 M acetic acid. Dilute to 50 mL with water. Add drops of
xylenol orange TS and enough methenamine (about 5 g) for the solution to turn violet. Titrate with
0.05 M disodium edetate VS, or 0.1 M VS as indicated in the monograph until color changes from
violet to yellow. Each mL of 0.05 M SV disodium edetate is equivalent to 10.36 mg of lead. Each mL
of 0.1 M disodium edetate VS is equivalent to 20.72 mg of lead.
Magnesium
Accurately weigh the amount of the substance indicated in the monograph and dissolve in 5 to 10 mL
of water, or in a minimum amount of 2 M hydrochloric acid. Dilute to 50 mL with water. Add 10 mL
of ammonium chloride buffer pH 10.0, and a few drops of eriochrome black T TS. Titrate with 0.05
M disodium edetate VS, or 0.1 M VS as indicated in the monograph until color changes from violet
to blue. Each mL of 0.05 M disodium edetate VS is equivalent to 1.215 mg of magnesium. Each mL
of 0.1 M disodium edetate VS is equivalent to 2.431 mg of magnesium.
Zinc
Accurately weigh the amount of the substance indicated in the monograph and dissolve in 5 to 10 mL
of water, or in a minimum amount of 5 M acetic acid. Dilute to 50 mL with water. Add drops of
xylenol orange TS and enough methenamine (about 5 g) for the solution to turn violet. Titrate with
0.05 M disodium edetate VS, or 0.1 M VS as indicated in the monograph until color changes from
violet to yellow. Each ml of 0.05 M disodium edetate VS is equivalent to 3.268 mg of zinc. Each mL
of 0.1 M disodium edetate VS is equivalent to 6.536 mg of zinc.
Drugs that are weak bases or acids cannot be quantified in an aqueous medium, but can be in a non-
aqueous medium. Titration in a non-aqueous medium is based on the Brönsted-Lowry acid/basic
concept, in which the acid is a substance that donates protons whereas the base is the one that receives
protons. Potentially acidic substances are acidic only in the presence of a base to which they can
donate protons and vice versa.
The solvent therefore plays a very important role in determining the acid/base character of a
substance, as the strength of the acid or base depends on the solvent ability to receive or donate
protons. Water should be the solvent of choice due to its easy availability. However, the strongest
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.3-00
acid that can exist in an aqueous medium is the hydronium ion (H 3O+) whereas the strongest base is
the hydroxide ion (OH-), this is known as the solvent leveling effect. For assay of very weak acids or
bases, the titrant must be a very strong base or acid, respectively, for the acid-base reaction to take
place; however, due to water leveling effect, it is not possible to titrate such substances in an aqueous
medium.
Using weakly protophilic solvents such as acetic acid, titration of very weak bases is possible as the
acetonium ion (CH3COOH2+) is a much stronger acid than the hydronium ion. Acids stronger than
hydronium ion cannot be differentiated in aqueous media, but they can in acetic acid showing that the
decreasing order of strength of acids is perchloric, hydrobromic, sulfuric, hydrochloric and nitric.
Similarly, titration of weak acids is possible using basic solvents such as n-butylamine. Amidite (CH
-
3CH2CH2CH2NH ) is a much stronger base than hydroxide.
The solvents used for titration in a non-aqueous medium must meet certain requirements: (1) not react
with the substance or the titrant; (2) dissolve the substance, allowing at least the preparation of a 0.01
M solution; (3) dissolve the titration product and, if precipitation is unavoidable, the precipitate must
be compact and crystalline; (4) easily enable the visualization of the endpoint, whether it is measured
with the use of indicators or potentiometers; (5) be inexpensive and easy to purify.
For the titration of substances of a basic character (amines, nitrogenous heterocyclics, quaternary
ammonium compounds, alkaline salts of organic and inorganic acids and some amine salts) solvents
of a relatively neutral or acidic nature are used, with glacial acetic acid being the most used. Acetic
anhydride is reserved for very weak bases such as amides. The mixture of dioxane with acetic acid
can occasionally be used to reduce the dielectric constant and consequently lower the ionization
potential of acids favoring the neutralization reaction. As a titrant, a solution of perchloric acid in
acetic acid is generally used. Other useful titrants are perchloric acid in dioxane; p-toluenesulfonic
acid (tosic acid) and fluorosulfonic acid are commonly used with aprotic solvents such as chloroform.
For assay of salts of halogenated acids (hydrochloride, hydrobromide and hydroiodide), mercury
acetate must be added; it does not dissolve in acetic acid solution. Halide ion is too weak a base to
quantitatively react with perchloric acid in acetic acid. This ion can be quantitatively replaced by the
acetate ion being removed as a mercuric complex that does not dissociate. Acetate, which is a
relatively strong base in acetic acid, can be accurately titrated with perchloric acid.
For the titration of substances that behave like acids (acid halides, acid anhydrides, carboxylic acids,
amino acids, enols, imides, phenols, pyrroles and sulphates) solvents of a basic or aprotic nature are
used. For assay of substances with intermediate acidity, the use of dimethylformamide is common.
Whereas for assay of weak acids, stronger bases such as morpholine, ethylenediamine and n-
butylamine are used. Properly selected basic solvents can enable the selective determination of acid
mixtures. Two classes of titrants can be used for the determination of acidic substances: the alkali
metal alkoxides and the quaternary alkylammonium hydroxides. Sodium methoxide is the most used
alkoxide in a mixture of methyl alcohol and toluene or methyl alcohol and benzene. Lithium
methoxide in methyl alcohol and benzene is used for compounds that form a gelatinous precipitate in
titrations with sodium methoxide. The most used among hydroxides is tetrabutylammonium. With
quaternary ammonium hydroxides such as tetrabutylammonium hydroxides and
trimethylhexadecylammonium hydroxides (in a mixture of benzene and methyl alcohol or isopropyl
alcohol) there is the advantage that the salt of the titrated acid is, in general, soluble in the titration
medium.
It is important to protect solvents for the titration of acidic substances from excessive exposure to the
atmosphere due to CO2 interference. Therefore, an inert atmosphere or special apparatus can be used
during the titration. To determine the absorption of CO 2 proceed to the titration of the blank which
should not consume more than 0.01 mL of 0.1 M sodium methoxide VS per milliliter of solvent.
The assay endpoint can be determined potentiometrically or visually by color change. Generally the
choice of method is based on the pKa of the analytes in water. For bases with a pKa of the order of
4, detection is, in general, through indicators; for those whose pKa is between 1 and 4, detection is
potentiometric. In this case, the glass/calomel electrode is useful. In acetic acid, such an electrode
works as theoretically expected. For calomel electrode as reference, it is recommended to replace the
aqueous potassium chloride salt bridge with 0.1 M lithium perchlorate in glacial acetic acid for acid
solvent titration or with potassium chloride in methyl alcohol for basic solvent titration. The
determination of the endpoint in the quantification of acids whose pKa in water is around 7 can be
done with the use of an indicator. For acids with pKa between 7 and 11, potentiometric determination
is recommended, although in certain cases indicators such as azoic violet or o-nitroaniline are used
with less precision.
With the use of organic solvents, the high coefficient of cubic expansion of most of these in relation
to that of water must be considered. This is due to the possibility of variation in the titrant content in
a non-aqueous medium depending on the temperature. The titrant volume must be corrected,
multiplying it by the correction factor below:
where
t0= titrant standardization temperature,
t= titrant utilization temperature.
The most used systems for titration in non-aqueous medium are listed in Table 1.
Accurately weigh the amount of the substance indicated in the monograph and dissolve it in a
specified amount of solvent, or mixture of suitable solvents. In titration of salts of halogenated
acids,10 mL of mercury acetate RS should be added. Use the appropriate indicator or, in
potentiometric determination, use a suitable electrode titrating with 0.1 M perchloric acid VS in acetic
acid. To prepare the blank, proceed in the same manner, omitting the sample. If t0 is different from t
correct the volume by:
[1 + 0.0011(t0 – t)]
where
t0 = temperature at which the titrant was standardized;
t = temperature at which the titration was carried out.
METHOD I
Accurately weigh the amount of the substance indicated in the monograph and dissolve it in the
solvent, or mixture of suitable solvents. Use the recommended indicator or, if applicable, use the
appropriate electrode for potentiometric determination. Titrate with 0.1 M sodium methoxide VS
previously standardized with benzoic acid. Avoid carbon dioxide absorption. Carry out titration on
the blank preparation. Make the necessary corrections.
METHOD II
Accurately weigh the amount of the substance indicated in the monograph and dissolve it in the
solvent, or mixture of suitable solvents. Titrate with 0.1 M tetrabutylammonium hydroxide VS using
burette equipped with carbon dioxide absorber. Potentiometrically determine the endpoint. Carry out
titration on the blank preparation. Make the necessary corrections.
APPARATUS
The device (Figure 1) used in the determination of methoxyl consists of a round-bottomed flask with
a capacity of 50 mL to which a capillary side-arm with 1 mm of internal diameter is sealed for the
inflow of inert carrier gas - nitrogen or carbon dioxide. A vertical condenser 24 cm in height and
12 mm in external diameter is connected by ground joints to the flask, on the top of which a curved
tube is affixed, whose capillary end with 3mm in diameter is immersed in a scrubbing vial. The outlet
of the scrubber consists of a tube of about 10mm in diameter that ends in a removable tube of 6mm
in diameter immersed in the absorbent liquid.
PROCEDURE
Absorbent liquid: weigh 15 g of potassium acetate and dissolve in 150 mL of a mixture of glacial
acetic acid and acetic anhydride (9:1). Add 5 g of bromine to 145 mL of this solution. Prepare
immediately before use.
Add enough washer preparation to cover half of the gas scrubber. Transfer 20 mL of the absorbent
liquid to the absorption tube. Transfer to the flask the sample quantity corresponding to 6.5 mg of
methoxyl or the quantity indicated in the monograph, together with glass beads and 6 mL of hydriodic
acid. Moisten the ground joint with hydriodic acid and connect to the air condenser. Connect the two
parts of the device by the ball joint using silicone grease for sealing. Adjust the gas inflow through
tube B so as to form two bubbles per second in the gas scrubber E. Gradually heat the flask for 20 -
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.3-00
30 minutes to 150 ºC and keep heating at this temperature for 60 minutes. After cooling the flask to
room temperature under gas flow, pour the preparation contained in the absorption tube into an
Erlenmeyer flask with a capacity of 500 mL with a ground cap containing 10 mL of the aqueous
solution of sodium acetate trihydrate (1:5). Wash the tube walls with water, transfer the wash water
to the Erlenmeyer flask and dilute to 200 mL with water. Add formic acid dropwise while shaking
until the reddish color of bromine disappears, then 1 mL of formic acid. Add 3 g of potassium iodide
and 15 mL of M sulfuric acid; cap, shake gently and allow to stand for five minutes.
Titrate the released iodine with 0.1 M sodium thiosulfate VS, using starch TS as indicator. Carry out
titration on the blank preparation proceeding as described, omitting the sample and correcting if
necessary. Each mL of 0.1 M Na 2S2O3 VS is equivalent to 0.5172 mg of methoxyl (CH3O).
APPARATUS
The apparatus (Figure 1) used in the determination of sulfur dioxide consists of a three-neck round-
bottom flask with a capacity of 1000 to 1500 mL. A device designed for the inflow of carbon dioxide
is attached to one of the flask side outlets. A 100 mL capacity addition funnel and vertical reflux
condenser, both fitted with ground joints, are coupled to another side outlet and to the central outlet,
respectively. At the upper end of the condenser, the absorption tube D is connected.
PROCEDURE
Transfer approximately 300 mL of water to the flask, fix the flask to the device and promote a slow
and uniform inflow of carbon dioxide for 15 minutes. Transfer 20 mL of 3% (w/v) hydrogen peroxide
RS, previously neutralized with 0.1 M sodium hydroxide, to the absorption tube using bromophenol
blue TS as indicator. Without interrupting the inflow of gas, momentarily remove the funnel and
accurately transfer to the flask about 50 g of sample and 200 mL of water. Add, dropwise, 50 mL of
6 M hydrochloric acid through the funnel and reflux for 45 minutes. Exactly transfer, by washing with
water, the liquid contained in the absorption tube to a 250 mL Erlenmeyer flask and titrate with 0.1
M sodium hydroxide VS using bromophenol blue TS as indicator. Carry out titration on the blank
preparation proceeding as described, omitting the sample and correcting if necessary. Each mL of 0.1
M sodium hydroxide VS is equivalent to 3.203 mg of sulfur dioxide.
PROCEDURE
Notes:
1 - A distilling flask with a capacity of two to four times the volume of the liquid to be heated must
be used.
2 - During all manipulations, take care to minimize the loss of alcohol through evaporation. 3 – To
avoid the occurrence of violent boiling, add fragments of insoluble and porous material, such as
silicon carbonate or glass beads.
4 - Liquids that form too much foam during the distillation must be previously treated with
phosphoric, sulfuric or tannic acid, up to a strong acid reaction or with a slight excess of calcium
chloride solution, or with a small amount of paraffin or silicone oil, before starting the distillation.
5 - The speed of distillation must be such as to allow the production of clear distillates. Turbid
distillates should be clarified by shaking with talcum powder or calcium carbonate, precipitated and
filtered. Adjust the temperature of the filtrate and determine the alcohol content by density.
METHOD 1
Liquids with less than 30% alcohol – Transfer to a suitable distillation apparatus, accurately, a sample
volume of minimum 35 mL of the liquid in which the alcohol content is being determined, record the
temperature at which the volume was measured. Add an equal amount of water, distil and collect a
volume of distillate that is about 2 mL smaller than the initial sample volume. Adjust the temperature
of the distillate to that at which the sample was measured and add enough water to obtain the initial
volume of the sample and homogenize. The distillate should be clear or, at most, slightly turbid.
Determine the density of the liquid at 20°C. With the result, evaluate the percentage, in volume, of
C2H5 OH contained in the examined liquid, using the Table of Alcohol.
METHOD 2
Liquids with more than 30% alcohol – Proceed as indicated in the previous method, with the
following modification: dilute the sample with twice the volume of water and collect a volume of
distillate approximately 2 mL less than twice the initial volume of the sample. Adjust the temperature
of the distillate to that at which the sample was measured and complete with water at a volume equal
to twice the initial volume of the sample. Homogenize and determine density at 20°C. The proportion
of C2H5OH, by volume, in this distillate, evaluated by density, is equal to half that of the liquid
examined.
Special treatments
Volatile Acids and Bases – Liquids containing volatile bases should be treated with dilute sulfuric
acid RS until a slightly acidic reaction. If volatile acids are present, sodium hydroxide RS should be
added to the preparation until slightly alkaline reaction.
Glycerol – Liquids containing glycerol must be added in such a volume of water that the residue, after
distillation, contains minimum 50% of water.
Iodine – Solutions containing free iodine should be treated prior to distillation with pulverized zinc
or bleached with a sufficient amount of 10% (w/v) sodium thiosulfate solution followed by the
addition of a few drops of sodium hydroxide RS.
Other volatile substances – Elixirs, tinctures and similar preparations that contain significant
proportions of volatile substances, in addition to alcohol and water, such as: volatile oils, chloroform,
ether, camphor etc., must undergo, before distillation, one of the following treatments .
1) Liquids with less than 50% alcohol – Weigh accurately 35 mL of the sample, and homogenize
with an equal volume of water, in a separating funnel, saturating this mixture with sodium chloride.
Extract the volatile components by shaking with a 25 mL portion of hexane. Transfer the lower layer
to a second separating funnel and repeat the extraction with two more portions of hexane. Collect the
hexane portions and treat with 3 portions of 10 mL saturated sodium chloride solution. Collect the
saline solutions and distil, collecting a volume of distillate corresponding to twice the initial volume
of the sample.
2) Liquids with more than 50% alcohol – Measure a sample and dilute with water so that it contains
approximately 25% alcohol and its final volume is approximately 35 mL. Then proceed as indicated
for liquids with less than 50% alcohol, proceeding from “...saturating this mixture with sodium
chloride”.
When preparing collodion for distillation, use water instead of the saturated sodium chloride solution
indicated above. If treatment with hexane was not used in the sample and the distillate obtained is
turbid (due to the presence of volatile oils present in small proportions), it can be clearer and suitable
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.3.3-00
for density determination, by shaking with about 1/5 of its volume of hexane or by filtration through
a thin layer of talcum powder.
Standard solution
For liquids containing more than 10% alcohol, prepare two standard solutions of alcohol in water so
that the concentrations are respectively about 5% below (Standard solution 1) and about 5% above
(Standard solution 2) of the expected alcohol concentration in the sample under analysis. Determine
the density of each of the standard solutions at 20 ºC (5.2.5) and obtain the exact concentration of
C2H5 OH from the Table of Alcohol. For liquids containing less than 10% alcohol, accurately prepare
two standard alcohol solutions so that the concentrations are respectively about 1% lower and about
1% higher than the expected concentration, diluting with water. Determine the densities of the
solutions in the same procedure as above.
APPARATUS
Under typical conditions, the instrument contains a 2 m x 4 mm column loaded with 20% macrogol
(polyethylene glycol) 400 on calcined chromatographic silica. The column is kept at a temperature of
100°C; the injector is equipped with a filter for solids and is kept at 160°C; as a conductor, inert gas
such as helium is used, flowing at a flow rate of about 60 mL per minute.
PROCEDURE
Proceed with the sample and each of the standard solutions as follows: transfer 25 mL to a suitable
ground-stopper container, add 1.0 mL of the internal standard (acetone, unless otherwise specified in
the monograph) for each 6% alcohol estimated in the sample and homogenize. Add water only if
necessary to make the solution. Inject the appropriate amount of the solution into the apparatus.
Calculate the ratio between the area under the alcohol peak and the area under the peak of the internal
standard in the chromatograms. Calculate the percentage of alcohol in the sample using the formula
𝑃1 (𝑌 − 𝑍) + 𝑃2 (𝑍 − 𝑋)
(𝑌 − 𝑍)
where
P1 = percentage of alcohol in standard solution 1,
P2 = percentage of alcohol in standard solution 2,
X = ratio between the area under the alcohol peak and the area under the peak of the internal standard
of Standard solution 1,
X = ratio between the area under the alcohol peak and the area under the peak of the internal standard
of Standard solution 2,
Z = ratio between the area under the alcohol peak and the area under the peak of the internal standard
of Sample solution.
If the value obtained is outside the range of the values included by the standard solutions, repeat the
procedure using those that provide a range that includes the sample value.
Accurately weigh the amount of sample containing 4 to 10 mg of protein and transfer to a 20 x 150
mm test tube with screw cap and polytetrafluoroethylene disc previously washed with 0.2 M sodium
hydroxide, rinsed and dried in oven. If the sample is solid, add 5 mL of hydrochloric acid and 5 mL
of water. If the sample is liquid, add hydrochloric acid so that the final concentration of hydrochloric
acid is 6 M. Remove oxygen from the tube by nitrogen flow for two to three minutes and then close
the tube with a disc and screw cap. Place the tube in a vertical position in an oven regulated between
108 ºC and 112 ºC, keeping it for 22 hours. Time elapsed, remove the tube from the oven and, while
still standing, cool it in running water or ice bath. Transfer the mixture to a 10-mL volumetric flask,
quantitatively, adjust the volume with distilled water. If there is any residue or precipitate, remove it
by centrifugation and filtration on a sintered glass plate or a 0.45 mm porosity filter membrane.
Accurately measure 5.0 mL of the solution, transfer to a round-bottomed flask and remove the solvent
under reduced pressure at a maximum of 50 ºC. Transfer 10 mL of distilled water to the flask residue
and re-evaporate. This operation must be repeated twice more, or until the residue does not present
an odor of hydrochloric acid. Dissolve the dry film formed by the hydrolyzate in an appropriate
volume of pH 2.2 citrate buffer (0.20 M in Na +). The resulting amino acid solution must then be kept
in a glass flask, capped and refrigerated until the analysis is performed.
Accurately weigh the amount of sample containing 10mg of protein and transfer to a 150 mL round-
bottomed flask and ground mouth. Add 40 mL of 6 M hydrochloric acid and some glass beads to the
medium. Connect a reflux condenser and start heating the flask using heating mantle. Keep the
suspension under constant and gentle boiling for 24 hours. Cool to room temperature and
quantitatively transfer the contents to a 50 mL volumetric flask, completing the volume with distilled
water, proceeding from “...If there is any residue or precipitate...” of the procedure described in
Method for hydrolysis of isolated proteins and peptides.
Properly dilute the solution with pH 2.2 citrate buffer (0.20 M in Na+) and then analyze it. If it is in
powder or tablet form, dissolve the sample in 0.1 M hydrochloric acid. Transfer the material to a
volumetric flask and complete the volume with the same buffer as above. Filter the preparation and
keep refrigerated (4°C) until analyzed.
Due to losses during the acid hydrolysis of proteins, sulfur amino acids are preferably analyzed by
means of their respective oxidized derivatives. Oxidation is promoted by performic acid, which
converts cystine and cysteine into cysteic acid and methionine into methionine/sulfone, both resistant
to hydrolysis conditions.
Accurately weigh the sample quantity containing 10mg of protein and transfer to a 25 mL round
bottom flask and add 2 mL of performic acid in ice bath. If the sample is soluble, keep the mixture in
an ice bath for four hours and, if the sample is insoluble, for 16 hours. Add 0.5 mL of 40%
hydrobromic acid to remove excess performic acid. Couple the flask to a rotary evaporator and
remove the residual bromine by means of reduced pressure, passing the vapors through M sodium
hydroxide solution. Proceed with the hydrolysis as described above.
The separation of amino acids into hydrolysates is usually performed by ion exchange
chromatography using sulfonated polystyrene resins in amino acid analyzers. In these devices, after
separation, the eluted amino acids from the chromatographic columns form blue/violet colored
substances by reaction with ninhydrin and the quantitative determination is made
spectrophotometrically. When using autoanalyzers of amino acids, the specifications of the respective
manufacturers must be followed.
Standard solution: accurately weigh the quantity of the chemical reference substance (CRS),
previously dried, specified in the individual monograph, and dissolve using the solvent described in
Table 1 or as described in the monograph. Quantitatively dilute with the same solvent to obtain a
solution with known final concentration, specified in Table 1 or as described in the monograph.
Transfer 2.0 mL of this solution to a 250 mL erlenmeyer with lid.
Sample solution: if not specified in the individual monograph, accurately weigh the sample quantity
and dissolve using the solvent described in Table 1. Quantitatively dilute with the same solvent to
obtain a solution with known final concentration, specified in Table 1. Transfer 2.0 mL of this
solution to a 250 mL erlenmeyer with lid.
*If not specified, Solution 1 is the one defined in the section Solutions in Microbiological Assay of Antibiotics
(5.5.3.3), except that sterilization is not required.
PROCEDURE
Inactivation and titration: to each erlenmeyer containing, respectively, 2.0 mL of the Standard
Solution and the Sample Solution, add 2 mL of 1.0 M sodium hydroxide, homogenize with circular
movements and allow to stand for 15 minutes. Add 2 mL of 1.2 M hydrochloric acid, 20.0 mL of
0.005 M iodine VS, cap immediately and allow to stand for 15 minutes. Titrate with 0.01 M sodium
thiosulfate VS. Close to the titration endpoint, add three drops of starch TS and proceed with titration
until the blue color disappears.
Blank assay: Transfer 20.0 mL of 0.005 M iodine VS to each erlenmeyer flask containing 2.0 mL of
Standard solution. If the Standard Solution contains amoxicillin or ampicillin, immediately add 0.1
mL of 1.2 M hydrochloric acid. Titrate with 0.01 M sodium thiosulfate VS. Close to the titration
endpoint, add three drops of starch TS and proceed with titration until the blue color disappears.
Proceed similarly for an Erlenmeyer flask containing 2.0 mL of Sample Preparation.
Calculations: if not specified in the individual monograph, calculate potency, in µg or units per mg
of the sample (active pharmaceutical ingredient or dosage form) using formula 1 and formula 2, or
only formula 3, described below.
Calculate the equivalence factor (F), in micrograms or Unit, for each milliliter of 0.01 M sodium
thiosulfate VS consumed by the standard preparation according to formula 1:
2(𝐶𝑝 × 𝑃𝑝 )
𝐹= (Formula 1)
𝑉𝑏𝑝 − 𝑉𝑝
where
Calculate the potency, in µg or Units per mg of the sample (active pharmaceutical ingredient or
pharmaceutical preparation) according to formula 2:
𝐹(𝑉𝑏𝑎 × 𝑉𝑎 )
(Formula 2)
2𝐶𝑎
where
Calculate the potency, in µg or Units per mg of the sample (active pharmaceutical ingredient or
pharmaceutical form) according to Formula 3:
(𝑉𝑏𝑎 − 𝑉𝑎 ) × 𝑃𝑝 × 𝐶𝑝
𝑃= (Formula 3)
(𝑉𝑏𝑝 − 𝑉𝑝 ) × 𝐶𝑎
where
5.4.1.1 SAMPLING
Due to the characteristics of herbal drugs, in particular the lack of homogeneity, special procedures
are required in relation to the tests to be carried out. The sampling procedures take into account three
aspects: number of packages that contain the drug; degree of drug division and amount of drug
available.
NUMBER OF PACKAGES
Examine the integrity of the packaging containers and the nature of the drug contained therein. If
external examination of the packages and labels indicates that the batch is homogeneous, take
individual samples from a number of randomly selected packages, as indicated in Table 1. If the
batch is not homogeneous, it should be divided into sub batches as uniformly as possible. Carry out
sampling with each fraction as a batch.
Carry out sampling of the top, middle and bottom of each package from top to bottom and bottom to
top (vertical direction) and laterally (horizontal direction).
Fragments smaller than 1 cm: remove the sample with the aid of a sampler (tube fitted with a closing
device at the base). Collect samples of at least 250 g for batches of up to 100 kg of drug. For batches
larger than 100 kg, take 250 g samples for every 100 kg of drug and obtain a final 250 g sample by
quartering.
Fragments larger than 1 cm: remove samples manually. Homogenize the samples taken from each
open package, taking care not to increase the degree of fragmentation or significantly modify the
moisture content during handling.
For drug quantities up to 100 kg, the sample must consist of at least 500 g. If there is more than 100
kg of drug, proceed with sampling followed by selection by quartering, generating a 500 g sample at
the end of the process.
In both cases, drugs with dimensions less than or more than 1 cm, it is permitted to sample quantities
lower than those specified above provided that the total amount of available drug is less than 10 kg.
However, the final sample should not be inferior to 125 g.
In case of large bales or packages, samples must be collected from more than 10 cm from the edges,
as the surface moisture content is different in relation to the inner layers.
QUARTERING
Combine and homogenize the samples taken from each open package, taking care not to increase the
degree of fragmentation or significantly modify the moisture content during handling.
Evenly distribute the sample in the shape of a square, divide it into four equal parts and discard the
portions into two opposite squares on one of the diagonals. Add the remaining two portions and repeat
the process, until the indicated amount is obtained. If there is a marked difference in fragment
dimensions, perform manual separation and record the approximate percentages of components with
different degrees of division found in the sample.
Size
Length, width and thickness measurements must coincide with those quoted in the monographs. Small
fruits and seeds require a sample of ten units and further calculation of the mean and standard
deviation.
Color
Examine the sample before any treatment, in daylight or under a lamp with a wavelength similar to
that of daylight. The color of the sample must be compared to the reference material.
Examine the untreated sample. When necessary, use a magnifying glass from five to ten times. When
indicated in the monograph, moisten with water or a specified reagent to observe fracture surface
characteristics. Touch the material to check whether it is soft or hard, bending and breaking the
material to obtain information on the fragility and appearance of the fracture, whether fibrous,
smooth, rough, grainy, among others.
Odor
Before checking the odor of the material, make sure there is no risk to health. Place a small sample
in the palm of your hand or in a glass container and inhale slowly and repeatedly. If the odor is
indistinct, press some of the material between your fingers and inhale again. When the monograph
indicates a toxic risk, place some crushed material in hot water. Determine the intensity of the odor
and classify it according to characteristics: none, weak, distinct or strong; and then in relation to the
sensation caused by the odor: aromatic, fruity, musty or rancid. When possible, it is important to
compare the odor with a defined substance, such as peppermint, which should have an odor similar
to menthol and cloves, similar to eugenol.
Taste
Plant organs or their parts are normally dry, and to be sectioned and observed under an optical
microscope, it is convenient to first soften them by treatment with hot water or a hydration solution.
The time required for softening each plant organ or its parts varies according to its texture. In fresh
organs, only those with firmer consistency need such treatment.
Place the sample in a suitable container: a) on a heating plate, or metallic mesh with water, in an
amount of 20 to 30 times the volume of the sample, gently heating until boiling, keeping for five
minutes and if softening is not enough, add detergent and boil for another five minutes; or b) in a
hydration solution, prepared with five parts of water, four parts of ethyl alcohol, one part of glycerol
and five drops of commercial detergent for each 200 mL of solution, in an oven at 60 ºC, for a variable
period, according to the material texture. Flowers and leaves tend to hydrate in a few minutes, while
hard materials such as husks and seeds require a variable amount of time in heated water as in a);
according to the degree of lignification, or hours or days in the hydration solution b). In direct
hydration in water a), carefully observe the time, as excessive softening may occur, preventing
observation under an optical microscope. In both methods, periodically check the material
consistency. For future analyses, determine the time each herbal drug needs to acquire the consistency
that allows for sectioning.
Once hydrated and softened, proceed with the preparation of the sections of the vegetable organs or
their parts. They must be performed transversally to the axis of the organ, or as established in the
individual monographs. In these, longitudinal or tangential cuts (barks, roots, etc.) or paradermal
sections are requested to observe the epidermis of foliaceous organs (leaves, sepals and petals).
Freehand sections are made with the aid of cutting slides. Very small or very thin structures require
the sample to be firmed or embedded in suitable material. Better quality sections can be obtained
using microtomes. Select the thinnest slices to observe under the microscope at 10 times.
Submerge sections in 50% sodium hypochlorite solution to eliminate cell content. Allow to act until
the sections are transparent (maximum 10 to 15 minutes). Wash the sections with distilled water to
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.4.1-00
eliminate sodium hypochlorite until neutral pH. Place sections in 0.05% Toluidine Blue solution for
10 seconds. Wash with distilled water, then with 0.5% acetic acid solution, and again with distilled
water. Place between slide and cover slip with two to three drops of a mixture of glycerin-distilled
water (1:1) and observe under an optical microscope at 10 and 40 times. The cellulosic walls will be
dyed purple pink. The lignified walls and walls with tannins will be dyed a bright greenish-blue color
and the color obtained may not remain stable.
TISSUE DISSOCIATION
This method is mainly used for the analysis of leaves, herbaceous stems and bark. The crystals remain
intact. Starch grains lose their characteristic structure.
Place a portion of the plant material in a 30 mL beaker. Add 10 mL of 5% sodium hydroxide solution
and boil for five minutes. Cool and transfer to a centrifuge tube. Centrifuge for two minutes, discard
supernatant solution and wash with distilled water. Place a portion of the centrifuge on a slide with
two or three drops of a mixture of glycerin-water (1:1). Insert the coverslip and press. Observe under
an optical microscope, with 10x and 40x magnification.
Weigh 1 to 2mg of the drug and place a small portion, with a fine, soft brush, on a slide. Add two or
three drops of 5% lactic acid solution (diaphanizing), and if necessary, before placing the coverslip,
add one or two drops of water or a mixture of glycerol and ethyl alcohol (1:1), mixing well with the
brush. Insert the coverslip. Observe under an optical microscope, with 10x and 40x magnification.
The stomata value is used in the analysis of laminar structures, such as leaves, lamina leaves and
bracts, counting the number of stomata in a given area of the epidermis. For this count, prepare
portions of about 0.5 cm by 0.5 cm of the leaf slide, submerged in a mixture of 10 mL of chloral
hydrate and water (5:2), in a beaker, boiling for 10 to 15 minutes, until the material is transparent.
Carry out the operation in a fume hood. Place a piece of the prepared leaf on a slide, with the abaxial
epidermis facing up. For very thick leaves, section each portion close to the abaxial epidermis,
ensuring that this face is placed correctly on the slide, with the epidermal layer facing the coverslip.
Add 2-3 drops of the mixture of chloral hydrate and water (5:2) and cover with a coverslip. Observe
under an optical microscope, with 10x magnification. Count the epidermal cells and stomata that
appear in the area. The value is calculated according to the formula 100S/(E+S), where S is the
number of stomata in a determined area of the leaf surface whereas E is the number of epidermal
cells, including trichomes existing in the same microscopic field observed. For each sample, carry
out and calculate the average of minimum ten determinations.
Histochemical reactions
Reactions can be carried out with fresh or dry sectioned material, material cut in a microtome or with
the powder of the herbal drug. The material is placed properly distributed on a slide, adding one or
two drops of the reagent. Place coverslip and observe under an optical microscope, with 10x and 40x
magnification.
Starch
Add one or two drops of iodine solution RS diluted (1:5) in water. Starch grains turn blue or blue-
violet in color.
Add one or two drops of 2 M hydrochloric acid or 6% (w/v) acetic acid. The presence of calcium
carbonate is indicated by effervescence. Calcium oxalate crystals take longer to dissolve, do not
release bubbles and are insoluble in 6% acetic acid.
Hydroxyanthraquinones
Add one drop of 5% potassium hydroxide (w/v). Cells containing 1,8-dihydroxyanthraquinones stain
red.
Inulin
Add one drop of 20% 1-naphthol solution in methyl alcohol, followed by one drop of sulfuric acid.
Inulin spheral crystals stain red or reddish-brown and dissolve.
Lignin
Add one drop of phloroglucin RS, quickly heat the slide and add one drop of 25% (w/v) hydrochloric
acid. The lignin stains red.
Add one or two drops of Sudan III RS or Sudan IV RS reagent, allowing to be in contact for 10
minutes, wash with 70% ethyl alcohol (v/v). Lipids, cutin and suberin stain from reddish-orange to
red in a short time.
Submerge the dry sample in a thionine solution, allowing to stand for 15 minutes, washing in 20%
ethyl alcohol (v/v). Mucilages appear as spherical globules with a reddish-violet color, while
cellulose, pectin and lignified partitions are colored blue or blue-violet. Mucilage also appears as
dilated and transparent spherical fragments on a black background, adding a drop of India ink to a
dry sample.
Proteins
Carry out this procedure only with fresh material. Add 0.5% (w/v) ninhydrin in absolute ethyl alcohol,
and keep at 37°C for 24 hours. Wash in absolute ethyl alcohol followed by distilled water, add
bleached fuchsin RS and allow to be in contact for 10 to 30 minutes. Wash in water and add 2%
sodium bisulfite (w/v), leave in contact for one to two minutes. Wash under running water for 10 to
20 minutes. The proteins stain purple red.
Saponins
Add a drop of sulfuric acid. A yellow color sequence occurs, followed by a red color, and finally a
violet or blue-greenish color.
Tannins
Add 5% ferric chloride (w/v) and a small amount of sodium carbonate, leave in contact for two to
three minutes, wash with distilled water. The tannins turn dark blue-greenish.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.4.1-00
Matter foreign to the drug is classified into three types: a) parts of the organism or organisms from
which the drug is derived, except those included in the definition and description of the drug, above
the tolerance limit specified in the monograph; b) any organisms, portions or products of organisms
not specified in the definition and description of the drug, in its respective monograph; and c) mineral
impurities or other dirt not inherent to the drug. During storage, products must be kept in clean areas
to avoid contamination. Take special precautions to prevent the proliferation of fungi, as some of
them can produce toxins.
Procedure
If not otherwise specified in the corresponding monograph, obtain by quartering the following sample
quantities:
- roots, rhizomes, barks, whole plant and aerial parts: 500 g
- leaves, flowers, fruits and seeds: 250 g
- fragmented herbal drugs of 0.5 g or smaller: 50 g
- powders 25 g.
Spread the sample in a thin layer on a flat surface. Manually separate material foreign to the drug,
initially with the naked eye and then with the aid of a magnifying glass (five to ten times). Weigh the
separated material and determine the percentage of foreign matter based on the weight of the sample
submitted for testing.
Sample preparation
Reduce the sample by cutting; granulation or fragmentation of the drugs not pulverized or crushed,
to limit the dimension of their components to approximately 3 mm thick. Seeds and fruits, even
smaller than 3 mm, must be broken. Avoid high speed mills to prepare the sample and take necessary
precautions not to modify the moisture content of the sample.
Gravimetric method
Accurately weigh approximately 3 g of the pulverized sample, or the amount specified in the
monograph, and transfer to a previously tared porcelain crucible. Distribute the sample evenly in the
crucible and incinerate, gradually increasing the temperature to a maximum of (600 ± 50) ºC, until
all the carbon is eliminated. A temperature gradient (30 minutes at 200 °C, 60 minutes at 400 °C and
90 minutes at 600 °C) can be used. At the end of the test, wait for cooling in a desiccator and weigh.
In cases where the carbon cannot be completely eliminated, cool the crucible and moisten the residue
with about 2 mL of water or saturated ammonium nitrate solution. Evaporate to dryness in water bath
and then place on a hot plate and incinerate until the difference between two serial weighing is not
more than 1.0 mg. Calculate the percentage of ash in relation to the dry drug.
Heat a porcelain crucible at red heat for 10 minutes, wait for it to cool in a desiccator and weigh.
Accurately weigh about 1.0 g of the drug in the previously tared crucible and moisten the drug with
concentrated sulfuric acid. Carbonize; and moisten again with concentrated sulfuric acid and
incinerate with gradual heating up to 800°C. Wait for cooling, weigh again, and incinerate for another
15 minutes. Repeat this procedure until the difference between two serial weighing is, at most, 1.0
mg.
Procedure
Heat the ash obtained to boiling, as indicated in total ash, with 25 mL of 2 M hydrochloric acid for
five minutes in a crucible covered by a watch glass. Wash the watch glass with 5 mL of hot water,
adding the washing water to the crucible. Collect the acid-insoluble material on a filter paper with
known ash content, rinsing with hot water until the filtrate is neutral. Transfer the filter paper
containing the residue to the original crucible, dry on a plate and incinerate at approximately 500ºC
until the difference between two serial weighing is, at most, 1.0mg. Calculate the percentage of
insoluble ash in relation to the dry drug.
Figure 1 – Apparatus for determination of volatile oil content in herbal drugs by the
hydrodistillation process
1) 500 mL to 1000 mL round bottom flask, short neck, fitted with a 24/40 female joint;
2) condenser, adaptable to the flask by means of a 24/40 male ground joint, built in a single piece of
glass, comprising the parts described below, with the respective measurements:
2.1) vertical tube (AC) 240mm in length and 13-15mm in internal diameter;
2.2) bent tube, with segments (CD) and (DE) measuring 150 mm in length each and internal diameter
of 10 mm;
2.3) Ball condenser, Allihn type (FG), 150mm in length and 15mm in internal diameter on the bulbs
and 8-10mm in the narrowing;
2.4) stopper (14/20 ground joint) (K’) containing an orifice of about 1 mm in diameter, which seals
a side outlet (K) provided with a 14/20 female ground joint at the end;
2.5) tube (GH) 30-40 mm in length and 7-8 mm in internal diameter, forming the parts (HK) angle
(GHK) of 35º;
2.6) pear-shaped widening (J) of 3 mL capacity;
2.7) tube (JL) fitted with a graduated scale of 100-110 mm; 1 mL capacity and subdivided into
0.01 mL;
2.8) bulb-shaped widening (L) of approximately 2 mL capacity;
2.9) three-way valve;
2.10) connecting tube (BM) 7-8mm in diameter, fitted with a safety tube. Insertion point (B) is
20mm above the highest part of the graduated scale;
3) appropriate heating device allowing precise regulation;
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.4.1-00
Use a perfectly clean and dry apparatus. Assemble the system in a place protected from drafts. Check
the graduated scale and, if necessary, establish a correction factor for each device. Proceed with the
assay, as established in the individual monograph and according to the drug nature.
Procedure
Introduce the volume of liquid indicated in the corresponding monograph and porous porcelain
fragments or glass beads into the flask. Adapt the condenser to the flask. Introduce the water through
the tube (N) until reaching the level (B). Remove the ground stopper (K’) and introduce the prescribed
amount of xylene using a pipette, through the opening (K), supporting the pipette tip on the bottom
of the lateral outlet (K). Place the K’ cap ensuring that the K and K’ orifices match each other. Heat
the liquid inside the flask until boiling begins and distil at a rate of 2 to 3 mL per minute, or as
indicated in the corresponding monograph.
To determine the speed of distillation, drain the water using a three-way valve, until the meniscus is
in the inferior reference line a (Figure 2). Close the valve and time the necessary time until the liquid
reaches the superior mark b. Open the valve and continue the extraction for 30 minutes, modifying
the heat to regulate the distillation speed. Turn off the heating, allow to cool for at least 10 minutes
and read the xylene volume in the graduated tube.
Superior
reference trace
3 mL
Inferior
reference trace
Introduce the amount of drug prescribed in the monograph into the flask and distil as described above,
for the time and speed indicated in the monograph. After the operation, wait for 10 minutes to cool
and read the volume of volatile oil collected in the graduated tube. Subtract the xylene volume
determined previously from the reading. The difference represents the amount of volatile oil
contained in the sample. Calculate the result in milliliters of volatile oil per 100 g of the drug.
When the determination of volatile oil is for analytical purposes, obtaining a mixture of volatile oil
and xylene, free of water, is carried out as described below: remove the K' cap and transfer 1.1 mL
of a solution of sodium fluorescein at 0 .1% and 0.5 mL of water. Reduce the volume of the essential
oil and xylene mixture inside tube L using the three-way valve. Allow to stand for five minutes and
slowly remove the mixture up to the level of valve M. Open the valve anticlockwise so that water
flows out of the BM connection tube. Thoroughly wash the tube with acetone, introduced through
tube N. Turn the valve anticlockwise so that it is possible to collect the mixture of xylene and volatile
oil in an appropriate container.
0.1 mL 0.1 mL
Weigh enough of the drug to obtain 0.5 to 2 mL of volatile oil into an appropriate round-bottomed
flask and add water to half of the container. Connect the condenser. Bring to a boil keeping a gentle
boiling for two hours, or as specified in the monograph.
Allow to stand for 10 minutes at room temperature, open the apparatus valve and slowly drain the
water until the surface of the oil layer reaches the zero line on the graduated tube. Allow to stand at
room temperature for about an hour and then measure the volume (mL) of the oil obtained.
The determination of fixed oils is based on their solvent extraction. After the solvent evaporation
process, the residue obtained, which is determined by weighing, represents the amount of fixed oils
present in the sample.
Procedure for samples with a high content of water-soluble substances (carbohydrates, urea, lactic
acid, among others): pre-treatment of the sample may be necessary in order to avoid interference in
the determination of fatty matters. Transfer the sample quantity to a funnel containing filter paper,
wash with water and dry the residue in an oven at 105ºC for two hours.
Use the Soxhlet device ( Figure 4), previously cleaned and dry, assembled in a place free from air
currents. The apparatus, made of resistant glass, of appropriate quality, comprises a round-bottomed
flask (A), with 500 mL to 1000 mL capacity, connected to the Soxhlet extractor (B) and reflux
condenser (C).
Procedure
volume, in milliliters, of the decoction used to prepare the dilution in the tube where the foam was
observed.
Accurately weigh approximately 4.0 g of the powdered and dry herbal drug and transfer to a 250-mL,
polished-necked erlenmeyer flask, previously weighed. Macerate, with 100 mL of solvent specified
in the individual monograph of the herbal drug, for 6 hours, shaking frequently, and allow to stand
for 18 hours. Quickly filter and transfer 25 mL of the filtrate to a pre-weighed crystallizer and
evaporate to dryness in water bath. Dry the flask in an oven at 105°C until constant weight. Calculate
the percentage of extracted materials in mg/g of dry plant material.
Accurately weigh approximately 4.0 g of the powdered and dry herbal drug and transfer to a 250-mL,
polished-necked erlenmeyer flask, previously weighed. Add 100 mL of solvent specified in the test
to the herbal drug and weigh to obtain the total weight, including the vial. Cap, shake and allow to
stand for an hour. Attach a reflux condenser and heat gently for one hour, cool and weigh. Correct
the original weight with the solvent used. Shake and filter quickly on a dry filter. Transfer 25 mL of
the filtrate to a pre-weighed crystallizer and evaporate to dryness in water bath. Dry the flask in an
oven at 105°C until constant weight. Calculate the percentage of extracted materials in mg/g of dry
plant material.
Accurately weigh about 2 g of the herbal drug and transfer to a Soxhlet extraction cartridge,
previously weighed and dried. Introduce 0.2 g of sodium hydroxide and sufficient absolute ethyl
alcohol into the extractor flask. Extract for five hours, remove the cartridge with the residue and dry
it in an oven at 105 ºC until constant weight. Calculate the percentage of extracted materials in mg/g
of dry plant material.
Each experimenter must rinse their mouth with fresh water before testing. To correct individual
differences in the determination of bitterness among the experimenters it is necessary to determine
the correction factor for each member. It is recommended that the group of experimenters consists of
minimum six people.
Stock solution
Weigh 0.1 g of quinine hydrochloride, dissolve in drinking water and dilute to 100 mL with the same
solvent. Transfer 1 mL to a 100 mL volumetric flask and adjust the volume with the same solvent
Reference solutions
Prepare a series of dilutions by adding 3.6 mL of the Stock Solution to the first tube and gradually
increasing the volume by 0.2 mL in each subsequent tube up to a total of 5.8 mL. Complete the
volume of each tube to 10.0 mL with drinking water.
Determine the highest dilution that still has a bitter taste. Place 10 mL of the weaker solution in the
mouth and pass it back and forth under the tongue for 30 seconds. If no clear bitter taste is found,
discard the solution and wait a minute. Rinse mouth with drinking water. After 10 minutes, test the
subsequent solution in ascending order of concentration. Calculate the correction factor (k) for each
experimenter using the following expression:
𝑛
𝑘=
5,00
n = volume in milliliters of the highest dilution of the stock solution in which a clear bitter taste was
found.
Note: experimenters unable to feel a distinct bitter taste in the reference solution prepared with 5.8
mL of the stock solution should be excluded from the group.
Sample preparation
If necessary, reduce the sample to powder (710 µm). Weigh 1.0 g of the sample and add 100 mL of
boiling drinking water. Heat in water bath for 30 minutes, shaking continuously. Allow to cool and
compensate the volume of evaporated water with drinking water. Shake vigorously and filter on filter
paper, discarding the first 2 mL of the filtrate. The filtrate is called C-1 and has a dilution factor of
100.
For liquid samples, take 1 mL and dilute with an appropriate solvent to 100 mL, naming it C-1.
Sample solutions:
10.0 mL of C-1 is diluted with water to 100 mL: C-2 FD 1000
10.0 mL of C-2 is diluted with water to 100 mL: C-3 FD 10 000
20.0 mL of C-3 is diluted with water to 100 mL: C-3A FD 50 000
10.0 mL of C-3 is diluted with water to 100 mL: C-4 FD 100 000
Starting with the C-4 dilution, each experimenter determines the dilution at which they experience
the clear bitter taste. This solution is called D. The dilution factor of this solution D is equal to Y.
Determine the volume in milliliters of solution D which, when diluted to 10 mL, still has a clear bitter
taste (X).
Calculate the Bitter Value for each experimenter according to the formula:
𝑌×𝑘
𝐼𝐴 = ( )
𝑋 × 0,1
Carry out the test simultaneously in triplicate. Accurately weigh approximately 1 g of the pulverized
herbal drug and transfer to a 25-mL ground-mouth cylinder. The length of the graduated part should
be approximately 125 mm and the inner diameter, close to 16 mm, with subdivisions of 0.2 mL
marked from 0 to 25 mL, ascending. Add 25 mL of water, or other defined agent, and shake every 10
minutes for one hour. Let the mixture stand for three hours at room temperature. Measure the volume,
in milliliters, occupied by plant material plus mucilage or any other adhered material subtracted from
the initial drug volume. Calculate the average value obtained from the individual determinations
carried out and relate it to 1 g of plant material.
Extracts are produced by an appropriate process employing ethyl alcohol or other suitable extracting
liquid. Different batches of a specific herbal drug can be combined prior to extraction. The drug can
also be subject to preliminary treatments such as enzyme inactivation, grinding or degreasing.
Additionally, unwanted substances (e.g. toxic or insoluble) can be removed after the extraction
operation.
Herbal drugs, solvents and other materials used for the preparation of extracts must be of adequate
quality and must comply with pharmacopoeial requirements and good manufacturing practices.
Solvents recovered from the extract concentration or drying process can be reused as long as the
recovery processes are controlled and monitored to ensure that the solvent meets specifications prior
to reuse or mixing with other materials. The water used for the production of extracts must comply
with the requirements of purified water monograph.
Where applicable, extractive solutions can be concentrated to the desired consistency using suitable
methods, generally under reduced pressure and at a temperature at which the possibility of
degradation of the constituents is reduced.
Volatile oils that have been separated during processing can be incorporated into the extracts at an
appropriate stage of the production process.
Suitable excipients can be added at different stages of the production process to enhance technological
properties (e.g. as part of the drying process, or to improve homogeneity or maintenance of extract
qualities).
Extraction with a certain solvent leads to obtaining typical constituents from the drying of the
extracting liquid. During the production of standardized and quantified extracts, purification
procedures can be applied to increase the proportion of certain constituents. Such extracts are named
purified.
IDENTIFICATION
TESTS
In the extracts production process, tests to verify microbiological quality (5.5.3.1), heavy metals
(5.3.2.3), mycotoxins (5.4.4), and pesticide residues (5.4.3) may be necessary, as per specific
regulation. Whenever a test for heavy metals is performed on the herbal drug, the same limits for
heavy metals indicated in the herbal drugs monographs apply to the extracts, unless otherwise
indicated in the individual extract monograph, or unless under justified and authorized reason.
ASSAYS
LABELING
Liquid extractive preparations consist of diversified products, obtained by liquid extraction, described
by their extraction solvents, production methods and drug-solvent ratio or drug-extract ratio. They
include products obtained using ethyl alcohol, water, glycerol, propylene glycol and fixed oils as
extraction solvents. Fluid extracts and tinctures belong to this category.
Fluid extracts can be adjusted, if necessary, to meet solvent content requirements. Fluid extracts can
be filtered if necessary.
Most are prepared by one of the four general processes described below and designated by the letters
A, B, C and D.
The maceration time and percolation rate vary according to the drug, aiming to fully extract the drug-
specific markers. Percolate flow rate is determined by the expressions percolate slowly (up to 1 mL
per minute); percolate quickly (3 to 5 mL per minute) and percolate at moderate speed (1 to 3 mL per
minute), in reference to the extraction of 1000 g of drug.
An extract, which, over time, deposits some sediment, can be filtered or decanted, as long as the
resulting liquid complies with pharmacopoeial specifications.
Process A
This process is used in the preparation of fluid extracts by percolation, in which the extracting liquid
is ethyl alcohol or a hydroethyl mixture.
Procedure: uniformly moisten 1000 g of the pulverized drug, with a sufficient quantity of the
indicated extracting liquid, and allow to macerate in a suitable container until the herbal drug swells.
Then transfer to a percolator. Strongly compress the drug and pour an additional and sufficient amount
of extracting liquid over it until an excess of supernatant liquid remains. When the liquid starts to
drip, close the lower outlet of the percolator, cap and allow to soak for the time prescribed in the
monograph. Percolate at the specified speed, adding more extractant liquid until the drug is depleted.
Separately collect the first 850 mL of percolate, if not otherwise specified in the monograph. Continue
the percolation until the drug is depleted and concentrate this remaining percolate until a syrup
consistency, with a maximum temperature of 60 ºC. Add this concentrated extract to the previously
separated percolate and, if necessary, add a sufficient amount of extracting liquid used to obtain 1000
mL of fluid extract.
Process B
Use this process in the preparation of fluid extracts in whose extraction, in addition to ethyl alcohol
or hydroethyl mixture, determined amounts of other components are used, such as acids, bases or
polyols (glycerol, ethylene glycol etc.), used successively in two extracting liquids. Extracting liquid
I contains a hydroethyl mixture and other components in the proportion required for the amount of
drug used and extracting liquid II, a hydroethyl mixture, in the indicated proportion, used to complete
the depletion of the drug.
Procedure: Uniformly moisten 1000 g of the pulverized drug with a sufficient amount of Extracting
Liquid I (this operation requires 600 mL to 800 mL of Extracting Liquid). Allow the drug, moistened,
to stand for about 15 minutes. Then transfer to a percolator, compress the drug strongly, and add the
remainder of the Extracting Liquid I. When the liquid starts to drip, close the outlet of the percolator,
cap and allow to soak for the time prescribed in the monograph. Percolate at the indicated flow rate
and, when the level of the extracting liquid I reaches the drug surface, continue the percolation with
the extracting liquid II until the drug is depleted. Separately collect the first 850 mL of percolate.
Continue the percolation until the drug is depleted and concentrate the remaining percolate until a
syrup consistency, with temperature not exceeding 60 ºC. Add this concentrated extract to the
previously separated percolate and add, if necessary, a sufficient quantity of extracting liquid II, to
obtain 1000 mL of fluid extract or adjust the volume according to the assay.
The process can be replaced by Process C, with the proper adjustment in the extraction liquid.
Process C
This process is that of fractional percolation, especially in substitution for processes A or B and
indicated for drugs that contain volatile or thermolabile constituents and/or when there is no adequate
apparatus for concentration and distillation. When using Process C instead of Process B, use
extracting liquid I throughout the percolation course.
Procedure: divide 1000 g of the drug previously pulverized into three portions of 500 g, 300 g and
200 g respectively. Evenly moisten the first portion with a sufficient amount of the extracting liquid.
Transfer the moisten powder to a suitable percolator, the capacity of which should not greatly exceed
the volume of drug in the percolator. Add extracting liquid until the drug is completely covered and
macerate for the time prescribed in the monograph. Then proceed with the percolation, separately
collecting the first 200 mL (F1) and then separately collect five serial fractions of 300 mL of
percolate, numbering them in the order in which they are obtained (F2-F6).
Moisten the second portion of the drug with a sufficient amount of F2 percolate; percolate, proceeding
as with the first portion of the drug, using the remaining portions of the percolate (F3-F6), obtained
in the first operation, as the extracting liquid, and using them in the order in which they were collected.
Collect and separate the first 300 mL of the new percolate (F7) and collect five more fractions of
200 mL each, numbering them in the order in which they are obtained (F8-F12).
Moisten the third portion of the drug with a sufficient amount of F8 percolate and proceed with the
percolation as in the previous operation, using as extracting liquid the 200 mL fractions of percolate
from the second portion (F9-F12), in the order in which they were collected. If there is no assay,
collect and separate 500 mL of percolate (F13). Homogenize the three percolates (F1, F7 and F13)
separated from the three portions of the drug, to obtain 1000 mL of fluid extract.
When necessary to carry out an assay for the fluid extract prepared by Process C, collect and separate
only 420 mL of percolate from the third portion instead of the 500 mL previously determined (F13).
Homogenize the three separate percolates (F1, F7 and F13) obtained from the three portions of the
drug and carry out an assay for a fraction of the mixture. If the content is higher than recommended,
adjust using the extracting liquid. If the content is lower than recommended, deplete the extracting
liquid from the percolator and repeat the extraction starting with the most concentrated percolate (F1,
F7 and F13) and then with the remaining percolates.
Process D
This process is used to prepare fluid extracts in which the extracting liquid is boiling water, adding
ethyl alcohol to the concentrated percolate as a preservative.
Procedure: weigh 1000 g of the coarsely pulverized drug and add about 3000 mL of boiling water,
homogenize thoroughly and allow to macerate in a suitable container for two hours. Transfer to a
percolator and elute at the specified speed, adding, little by little, boiling water until complete
depletion of the drug. Evaporate the percolates, in water bath or in a vacuum distiller, to the
determined volume. Wait for cooling, transfer the ethyl alcohol and allow the mixture to stand in a
closed container for 24 hours. Decant the clear liquid, filter the remaining, mixing them and wash the
filter residue with a sufficient amount of extracting liquid to obtain 1000 mL.
TESTS
Determination of mass density and relative density (5.2.5). Where applicable, the fluid extract
must comply with prescribed limits.
Determination of alcohol (5.3.3.8). For ethylic fluid extracts, the determination of the ethyl alcohol
content must be carried out. Where applicable, the ethyl alcohol must comply with prescribed limits.
Methyl alcohol and isopropyl alcohol (5.4.2.2.1). Maximum 0.05% (v/v) for ethylic fluid extracts,
unless otherwise prescribed or justified and authorized.
Dry residue (5.4.2.2.2). Where applicable, the fluid extract must comply with prescribed limits.
STORAGE
5.4.2.1.2 TINCTURES
Tinctures are usually prepared by maceration or percolation, using ethyl alcohol at an appropriate
concentration to extract the herbal drug, or by dissolving a soft or dry extract of the herbal drug (which
have been produced using the same extraction solvent that would be used to prepare the tincture by
direct extraction) in ethyl alcohol in the required concentration.
Tinctures can be adjusted to meet solvent content requirements. Tinctures can be filtered if necessary
and light sediment can form when standing.
TESTS
Determination of mass density and relative density (5.2.5). Where applicable, the tincture must
comply with prescribed limits.
Determination of alcohol (5.3.3.8). The content must comply with the limits defined in the individual
monographs.
Methyl alcohol and isopropyl alcohol (5.4.2.2.1). Maximum 0.05% (v/v) unless otherwise defined
or justified and authorized.
Dry residue (5.4.2.2.2). Where applicable, the tincture must comply with prescribed limits.
STORAGE
LABELING
Labels must contain, in addition to the requirements listed above, the percentage of ethyl alcohol
content (v/v).
Dry residue (5.4.2.2.2). Where applicable, the soft extract must comply with prescribed limits.
Solvents. Solvent residues must be controlled unless defined or justified and authorized.
STORAGE
5.4.2.1.4 OLEORESIN
The requirements below apply to oleoresins produced by extraction and non-natural oleoresins.
TESTS
Determination of water (5.2.20) Where applicable, oleoresin must comply with prescribed limits.
Solvents. Solvent residues must be controlled unless defined or justified and authorized.
STORAGE
TESTS
Loss by desiccation (5.2.9.1). Where applicable, dry extract must comply with prescribed limits.
Determination of water (5.2.20) When the desiccation loss test is not applicable, the dry extract
must comply with the defined limits.
Solvents. Solvent residues must be controlled unless defined or justified and authorized.
STORAGE
Keep the column temperature at 130°C, the injector temperature at 200°C and the detector
temperature at 220°C.
Sample solution: add 2 mL of the internal standard solution to a determined volume of distillate.
Dilute to 50 mL with water or 90% ethyl alcohol (v/v), adjusting the ethyl alcohol content to 10%
(v/v).
Procedure: Inject, separately, 1 μL of the Standard Solution and the Sample Solution, record the
chromatograms and measure the peak areas. Calculate the contents of methyl alcohol and isopropyl
alcohol in relation to the sample subject to distillation from the responses obtained with the Standard
solution and the Sample solution.
Limits
Unless indicated in the specific monograph, the herbal drug to be examined must minimally comply
with the limits indicated in Table 1. The limit to be applied to pesticides not established in Table 1
and whose presence is suspected for any reason must comply with the limits referenced in Brazilian
legislation. Limits that are not listed in Table 1 or indicated in Brazilian legislation must be calculated
according to the following formulas.
where
The maximum limits for pesticide residues in plant derivatives are calculated by the following
formula:
where
LARDV = Acceptable Limit of Pesticide Residues in mg/kg of the herbal drug shown in Table 1, in
the current legislation or calculated according to the formula above;
LARD = Acceptable pesticide residue limit in mg/kg of the vegetable derivative preparation.
RDE = Drug Extract Ratio.
The analyses may be totally or partially waived by the competent authority according to manners of
obtaining the raw material that indicate the absence of risk in relation to the presence of pesticide
residues.
Sampling
The analytical procedures used must be validated in compliance with the SANCO document in its
most updated version "Guidance Document on analytical quality control and validation procedures
for pesticide residues in food and feed" and meet at least the following criteria.
The chosen extraction method must be suitable for the mixture of pesticides to be investigated and
not cause interference.
Possible matrix interferences, for example, interferences of sulfur compounds in brassicaceae and
alliaceous, in the determination of dithiocarbamates such as CS2 should be considered. Reference
solutions and sample solutions must be within the linearity range of the detector.
Detection and quantification limits must be determined for each combination of pesticides and
matrices to be analyzed.
The repeatability and reproducibility of the method must not be inferior to that indicated in Table 2.
METHOD I
TLC visualization reagent solution: examine under ultraviolet light at 360-365 nm; 30% (v/v) sulfuric
acid solution.
Phosphate buffer solution pH 7.4: weigh 1.0 g of potassium chloride, 1.0 g of monobasic potassium
phosphate, 5.8 g of dibasic sodium phosphate anhydrous and 40.0 g of sodium chloride and transfer
to a 5 L volumetric flask. Add approximately 4.5 L of water and dissolve. Adjust the pH to 7.4 with
hydrochloric acid or sodium hydroxide. Adjust volume with water, homogenize and check pH again.
Aflatoxin Stock Solution: Dissolve the contents of the aflatoxin standard in a mixture of benzene and
acetonitrile (98:2). Dilute quantitatively and in steps with the same solvent until obtaining solutions
with a concentration of 8 µg/mL to 10 µg/mL of each aflatoxin. Shake the solution vigorously for one
minute. Determine the absorbance of each solution at 350 nm in an appropriate spectrophotometer,
using a mixture of benzene and acetonitrile (98:02) as blank. Calculate the concentration of the
respective aflatoxin, in mg/mL, using the following formula:
1000 × A × M
𝐶=
ɛ
M = molecular mass;
ɛ = molar absorptivity in the indicated solvent of the corresponding aflatoxin; and
A = solution absorbance
Standard solution: transfer aliquots of each of the previously prepared aflatoxin stock solutions to 3
mL vials with caps. Add sufficient amounts of benzene and acetonitrile (98:02) to obtain solutions
with 1 µg/ml of B1, 0.5 µg/ml of B2, 1 µg/ml of G1 and 0.5 µg/ml of G2.
Sample preparation
Column: Immunoaffinity chromatographic column (IAC) with monoclonal antibodies specific for
aflatoxins.
Extraction solvent: dissolve 5 g of sodium chloride in 200 mL of methyl alcohol and water (70:30)
Procedure: accurately weigh 25 g of sample, previously ground and sieved with sieve nr 20, transfer
to a 500 mL Erlenmeyer flask. Add enough extraction solvent to soak the entire sample. Shake in a
mechanical shaker for one hour or in a blender at high speed for five minutes. Filter and collect the
filtrate in a 250 mL Erlenmeyer flask. Transfer accurately measured 80 mL of the extract to a 250 mL
Erlenmeyer flask, add 160 mL of pH 7.4 phosphate buffer solution. Shake and filter through a
membrane filter with a porosity between 0.8 –1.6 µm. Apply 120 mL of the filtrate (equivalent to 5 g
of sample) on the immunoaffinity chromatographic column, maintaining a flow rate of one to two
drops per second, taking care that the column does not dry out. Wash the column with 20 mL of buffer
solution and dry by passing air through the column with the aid of a syringe. Discard the washing
liquid. Slowly elute the aflatoxins adsorbed on the column, by gravity, with 2 mL of methyl alcohol.
Collect the entire eluate in a 25 mL flask with a small container at the bottom, accurately pre-weighed.
Dry using rotary evaporator at 60°C. Weigh to obtain the mass of the residue. Dissolve the residue in
100 µL of a mixture of benzene and acetonitrile (98:02).
Aflatoxin analysis
Procedure: apply, separately, 10 µL of the Sample Solution, 2 µL, 4 µL and 6 µL of the Standard
Solution and 10 µL of the Solution fortified with standard solution. Allow to dry and develop the
chromatograms until the solvent front runs approximately 11 cm. Remove the plate and air dry,
protected from light. Examine under ultraviolet light (360 nm). Aflatoxins B1 and B2 appear as blue
stains and G1 and G2 as green stains. Rf values are approximately: 0.4 for G2, 0.5 for G1, 0.6 for B2
and 0.7 for B1, respectively. To confirm, pulverize the plate with the TLC visualization reagent
solution. Allow to dry in the dark and observe under 360 nm ultraviolet light: the four aflatoxins are
seen as yellow stains. Calculate the concentration of each aflatoxin, in µg/kg, in the portion of the
sample taken, using the formula:
P × C × V
𝐶=
𝑆 × 𝑚
Acceptance criteria
Absence of stains in test solution applications in areas where stains of the Standard Solution are
observed. If any stains are observed in the Sample Solution, check the correspondence with any
fluorescent stains in the Standard Solution to identify this aflatoxin. The intensity of the aflatoxin
stain, if present in the Sample Solution, when compared to the intensity of the corresponding aflatoxin
stain in the standard solutions, will provide the approximate concentration of the aflatoxins in the
Sample Solution. The maximum accepted limits are lower than 5 µg/kg for aflatoxin B1 and lower
than 20 µg/kg for the sum of aflatoxins B1, B2, G1 and G2, except when other values are
recommended in specific monograph.
METHOD II
Aflatoxin Primary Stock Solution: Dissolve aflatoxin B1 in a mixture of acetonitrile and toluene (2:98)
to obtain a solution at 10 µg/mL. To determine the exact concentration of aflatoxin B1 in the stock
solution, record the absorption curve between 330-370 nm in a quartz cell. Calculate the concentration
of B1 aflatoxin, in µg/mL, using the following formula:
A × M × 100
𝐶=
ɛ × l
where
A = absorbance determined at the maximum of the absorption curve;
M = molar mass of aflatoxin B1 (312 g/mol);
ɛ = molar absorptivity of aflatoxin B1 in the mixture of acetonitrile and toluene (1930 m2/mole); and
l = length of the optical path in the cell (1 cm).
Aflatoxin B1 secondary stock solution: prepare secondary solution containing 100 ng/mL of aflatoxin
B1 by diluting the primary stock solution with a mixture of acetonitrile and toluene (2:98). Wrap the
solution flask in aluminum foil and wait for the contents to reach room temperature. If the solution is
to be stored for a long period (e.g. one month), weigh the flask and record the mass before each use
of the solution.
Standard Aflatoxin Solutions: Transfer the volumes of secondary aflatoxin stock solution indicated
in Table 2 to volumetric flasks. Apply nitrogen gas to these solutions, at room temperature, until
solvent evaporation. In each flask, add 75 mL of methyl alcohol, wait for complete solubilization and
adjust to 250 mL with water and homogenize.
Analytical curve: prepare the analytical curve using standard solutions of aflatoxin B1, from one to
five, in a concentration range of 1 µg/kg to 8 µg/kg of aflatoxin B1 in the herbal drug. Check if the
curve has adequate linearity. If the aflatoxin B1 content in the sample to be examined is outside the
range of the analytical curve, the test solution must be diluted until the aflatoxin content is adequate
for the established calibration curve.
Column: 250 mm in length and 4.6 mm in internal diameter, packed with silica chemically bonded to
octadecylsilane group (5 µm)
Mobile phase A: mixture of acetonitrile, methyl alcohol and water (2:3:6) for post-column derivation
with photochemical reactor or pyridinium bromide.
Mobile Phase B: add 0.12 g of potassium bromide and 350 mL of diluted nitric acid per liter of Mobile
Phase A for post-column derivation with electrochemically derived bromide.
Post-column derivation with pyridinium bromide-perbromide (PBPB): use pulseless pump; T with
dead volume equal to zero; Teflon reaction tube (PTFE) of 0.45 m length and internal diameter = 0.5
mm; Mobile phase A; Post-derivation reagent: dissolve 50 mg of PBPB in 1000 mL of water (protect
from light and use within four days) and flow of derivation reagent: 0.4 mL/minute.
Post-column shunt with photochemical reactor (PHRED): use a low pressure mercury bulb reactor
(minimum 8 W) at 254 nm; polished backplate; reaction coil with PTFE tube tightly braided around
UV bulb, length 25 cm and diameter 0.25 mm, nominal dead volume 1.25 mL; two-minute exposure
time; and Mobile Phase A.
Immunoaffinity Column (IAC): use an immunoaffinity column containing antibodies against aflatoxin
B1, with a capacity of not less than 100 ng of aflatoxin B1 and with not less than 80% recovery for a
solution of 5 ng of aflatoxin B1 in one mixture of methyl alcohol and water (12.5:87.5) is applied.
Condition IAC at room temperature.
Procedure: weigh 5 g of dried and pulverized plant material, transfer and add 100 mL of water and
methyl alcohol mixture (30:70) and extract by sonication for 30 minutes. Filter on pleated filter paper.
Exactly transfer 10 mL of the clear filtrate to a 150 mL Erlenmeyer flask and add 70 mL of water.
Pass 40 mL through the immunoaffinity column (IAC) at a flow rate of 3 mL/minute (do not exceed
5 mL/minute). Wash the column with two 10 mL volumes of water at a flow rate not to exceed 5
mL/minute. Dry the IAC using a light vacuum for 5 to 10 seconds or air using a syringe for 10
seconds. Apply 0.5 mL of methyl alcohol to the top of the column and allow to elute by gravity into
a 5 mL volumetric flask. After one minute, apply another 0.5 mL of methyl alcohol. After one minute,
apply a third portion of methyl alcohol. Collect most of the applied solvent by blasting compressed
air across the top of the column or using light vacuum. Dilute with water to 5 mL and shake. If the
solution is clear, it can be used directly. Otherwise, filter in a filter unit before analysis. Use a
disposable filter unit (e.g. polytetrafluoroethylene filter with 0.45 µm pores) that does not cause
aflatoxin loss by retention.
Calculation: Determine the formula of the analytical curve (y = ax + b) with the aflatoxin B1
concentration (ng/mL) on the x-axis and the sign (S) on the y-axis. The concentration of aflatoxin B1
𝑠−𝑏
in the test solution is equal to 𝐶 𝑎 .
Calculate the content of aflatoxin B1 in the herbal drug, in ng/g, using the following expression:
𝑉1 × 𝑉2 × 𝐶
𝐶=
𝑚 × 𝑉𝑖
where
The presence of aflatoxin B1 can be confirmed by recording the chromatogram without post-column
derivation, which results in a large reduction (greater than 10-fold) in the response due to aflatoxin
B1.
When not determined in the monograph, the maximum total value of heavy metals of 20 ppm must
be observed, not exceeding the limits specified in Table 1.
Factor Xa chromogenic substrate: Factor Xa specific chromogenic substrate such as: N-α-benzoyl-
L-isoleucyl-L-glutamyl-glycyl-L-arginine-4-nitro-anilide hydrochloride. Reconstitute according to
manufacturer’s instructions.
Dilution buffer: 0.605% (w/v) tromethamine solution. If necessary, adjust to pH 8.4 with hydrochloric
acid.
Sample solution: dilute the sample with the Dilution Buffer to obtain a solution that supposedly
contains 0.1 IU of heparin per milliliter.
Standard solution: dilute the standard heparin solution with the Dilution Buffer to obtain a solution
containing 0.1 IU of heparin per milliliter. The conditions described apply to microplates. If the test
is carried out in tubes, adjust the volumes in order to maintain the proportions in the mixture. Shortly
before testing, place all solutions at 37°C in water bath. Distribute 20µL of normal human plasma
and 20µL of antithrombin III RS into a series of wells. Add a series of volumes (20 μL, 60 μL, 100 μL
and 140 μL) of the Sample Solution or Standard Solution to the wells and complete the volume of
each well with 200 μL using the Dilution Buffer (0.02 –0.08 IU of heparin per milliliter in the final
reactive mixture).
Transfer 40µL from each well to a second series of wells, add 20µL of the bovine Factor Xa solution
and incubate at 37°C for 30 seconds. Add 40µL of Chromogenic Substrate for Factor Xa solution at
1mmole/L and incubate at 37°C for three minutes. Stop the reaction by lowering the pH with an
appropriate reagent such as a 20% (v/v) glacial acetic acid solution and measuring the absorbance at
405 nm (5.2.14). The reaction time is generally on the order of three minutes to 15 minutes, but certain
variations are tolerated if they allow to improve the linearity of the dose-response curve.
KINETIC METHOD
Transfer 40µL from each well to a second series of wells, add 20µL of the bovine Factor Xa solution
and incubate at 37°C for 30 seconds. Add 40 μL of the Chromogenic Substrate for Factor Xa solution
at 2 mmole/L, incubate at 37 °C and determine the substrate cleavage rate by continuously reading
the absorbance variation at 405 nm (5.2.14), thus enabling calculate the initial rate of substrate
cleavage. This velocity must be proportional to the residual concentration of Factor Xa. Check the
validity of the test and calculate the activity of the sample through the statistical procedures applicable
to biological tests (8).
MATERIALS
Collagen: use native equine or human collagen fibrils type I or III. To facilitate handling, collagen
solutions can be used.
Collagen diluent: weigh 50 g of glucose and dissolve in water. Adjust the pH to between 2.7 and 2.9
with M hydrochloric acid and dilute to 1000 mL with water.
Buffered Wash Solution: 0.1% (w/v) polysorbate 20 solution in Phosphate Chloride Buffer.
Neutralizing reagent: prepare Chloride-phosphate buffer containing 0.1% (w/v) polysorbate 20 and
1.0% (w/v) bovine albumin.
Dilution buffer: prepare Chloride-phosphate buffer containing 0.1% (w/v) polysorbate 20 and 5.0%
(w/v) bovine albumin.
Substrate solution: dissolve, immediately before use, one o-phenylenediamine hydrochloride tablet
and one carbamide peroxide tablet in 20 mL of water, or use an adequate volume of hydrogen
peroxide. Protect from light .
Microplates: they must have a flat bottom, polystyrene plates with optimized surface properties for
immunoenzymatic assay and high binding capacity protein.
PROCEDURE
Sample solution: reconstitute the preparation to be analyzed as indicated on the label. Dilute with
Dilution Buffer to prepare a solution containing about 1 IU/mL of Von Willebrand Factor. Prepare
two independent runs with minimum three dilutions using the Dilution Buffer.
Standard solutions: reconstitute the standard solution as indicated by the manufacturer. Dilute with
Dilution Buffer to prepare a solution containing about 1 IU/mL of Von Willebrand Factor. Prepare
two independent runs with minimum three dilutions using the Dilution Buffer.
Dilute with Collagen Diluent, at room temperature, to obtain a solution containing 30 to 75 mg/mL
of collagen. Gently homogenize to produce a uniform suspension of collagen fibers and then pipet
0.1 mL and transfer to each well of the microplate. Cover plate with plastic wrap and incubate at 37°C
overnight. Empty collagen-coated plate wells by inverting and draining on a paper towel. Add 0.25
mL of Buffered Wash Solution. Empty plate wells by inversion and drain on a paper towel, repeating
this operation three times. Add 0.25 mL of Neutralizing Reagent to each well, cover the plate with
plastic film and incubate at 37°C for one hour. Plate wells should be emptied by inversion and
draining on a paper towel. Add 0.25 mL of Buffered Wash Solution. Empty plate wells by inversion
and drain on a paper towel. Repeat this operation three times.
Add 0.1 mL of each of the Sample or Reference Solutions to the wells. Add 0.1 mL of Dilution Buffer
to a series of wells to obtain the negative control. Cover plate with plastic wrap and incubate at 37°C
for two hours. Plate wells should be emptied by inversion and draining on a paper towel. Add 0.25
mL of Buffered Wash Solution. Empty plate wells by inversion and drain on a paper towel, repeating
this operation three times.
Prepare an appropriate dilution of Phosphate Chloride Conjugation Buffer containing 0.5% (w/v)
bovine albumin and add 0.1 mL to each well. Cover plate with plastic film and incubate at 37°C for
two hours. Empty plate wells by inversion and drain on a paper towel. Add 0.25 mL of Buffered Wash
Solution. Empty plate wells by inversion and drain on a paper towel. Repeat this operation three times.
Add 0.1 mL of Substrate Solution to each well and incubate at room temperature for 20 minutes in
the dark. Add 0.1 mL of M hydrochloric acid to each well. Measure the absorbance at 492 nm (5.2.14).
Use the absorbance values to estimate the potency of the preparation to be analyzed using the
statistical procedures applicable to biological tests. The assay is valid if the absorbances measured
for the negative controls are greater than 0.05.
The chromogenic determination method includes two successive steps: activation of Factor II by the
action of snake venom and the enzymatic cleavage of a chromogenic substrate by Factor IIa, which
REAGENTS
Factor II specific activator from viper venom (Ecarina): protein obtained from the venom of the Echis
carinatus viper, specifically activates Factor II. Reconstitute the preparation following the
manufacturer’s instructions. Once reconstituted, store at 4°C and for not more than one month.
Chromogenic substrate for Factor IIa: Factor IIa specific chromogenic substrate such as: HD-
phenylalanyl-L-pipecolyl-L-arginine-4-nitroanilide hydrochloride, 4-toluenesulfonyl-glycyl-prolyl-
Larginine-4-nitroanilide, HD-cyclohexylglycyl -α-aminobutyryl-L-arginine-4-nitroanilide, D-
cyclohexylglycyl-L-alanylarginine-4-nitroanilide-diacetate. Reconstitute following the
manufacturer’s instructions.
Dilution buffer: solution containing 0.606% (w/v) of tromethamine, 1.753% (w/v) sodium chloride,
0.279% (w/v) edetic acid and 0.1% bovine or human albumin (p/v). Adjust pH to 8.4 with
hydrochloric acid.
PROCEDURE
Sample solution: dilute the sample in the Dilution Buffer to obtain a solution containing 0.015 IU of
Factor II per milliliter. Prepare at least three more dilutions of this solution in Dilution Buffer.
Standard solution: dilute the sample in the Dilution Buffer to obtain a solution containing 0.015 IU
of Factor II per milliliter. Prepare at least three more dilutions of this solution in the Dilution Buffer.
Place the solutions contained in the microplates in water bath at 37°C, immediately before the assay.
If the test is carried out in tubes, adjust the volumes to maintain the proportions in the mixture.
Introduce 25 μL of the different dilutions of Sample Solution and Standard Solution into a series of
wells of the microplate kept at 37 °C. Transfer 125µL of Dilution Buffer and 25µL of Factor II
Specific Activator from viper venom into each well and incubate for exactly two minutes. Transfer
25µL of Chromogenic Substrate for Factor IIa to each well.
Read the absorbance change rate at 405 nm (5.2.14 and continue for three minutes to obtain the
average rate of absorbance change. If a continuous reading is not possible, determine the absorbance
at 405 nm at appropriate standardized consecutive ranges, e.g. every 40 seconds. Plot the linear graph
of the absorption values versus time and calculate the average rate of change in absorbance. From the
individual values found for each standard and sample dilution, calculate the sample activity and check
the validity of the assay using the usual statistical methods.
The International Unit of Factor II corresponds to the activity of a given quantity of the international
standard, constituted by a lyophilized concentrate of Factor IX of blood coagulation. The equivalence
in international units from the International Reference Standard is indicated by the World Health
Organization.
Reconstitute the sample and standard solution respectively according to the label directions and use
immediately. When applicable, determine the amount of heparin present and neutralize it by adding
protamine sulfate (10μg of protamine sulfate neutralizes 1.0 IU of heparin). Dilute the sample and
standard solution with pH 7.3 imidazole buffer to obtain solutions with 0.5 to 2.0 IU per milliliter.
With a mixture of 3.8% (w/v) sodium citrate and pH 7.3 (1:5) imidazole buffer, prepare a dilution
series comprising 1/10, 1/20, 1/40 and 1/80. These dilutions must be accurately prepared and are used
immediately.
For example, use incubation tubes kept in water bath at 37°C. Introduce 0.1 ml of plasma substrate
and 0.1 ml of each of the standard and sample dilutions into each tube. Transfer to each tube 0.1 mL
of an appropriate dilution of cephalin RS or platelet substitute and 0.1 mL of a suspension of 0.5 g of
light kaolin in 100 mL of 0.9% sodium chloride (w/v) and allow to stand for about 10 minutes, tilting
the tubes regularly. Add 0.1 mL of 0.74% (w/v) calcium chloride solution to each tube. With the aid
of a chronometer, determine the clotting time, that is, the time range between the moment of addition
of calcium chloride and the first indication of the formation of fibrin that is observed visually or with
appropriate devices. Calculate the activity using the statistical procedure applicable to biological
assays.
To ensure that there is no significant contamination of the plasma substrate by Factor IX, perform a
blank assay using, in place of the sample, a corresponding volume of a mixture of 3.8% (w/v) sodium
citrate and imidazole buffer of pH 7.3 (1:5). The test is only valid if the clotting time determined in
the blank test is between 100 and 200 seconds.
The International Unit of Factor VII corresponds to the activity of a given quantity of the international
standard, which is currently constituted by a lyophilized plasma. The correspondence between the
International Unit and the International Standard is indicated by the World Health Organization.
The chromogenic determination method comprises two successive steps: the activation of Factor X,
under the action of Factor VIIa, in a reactive mixture containing Tissue Factor/phospholipid and
calcium ion and the enzymatic lysis of a chromogenic substrate by Factor Xa that releases a
chromophore quantifiable by spectrophotometry. Under proper assay conditions, there is a linear
relation between the rate of formation of Factor Xa and the concentration of Factor VII. The following
diagram summarizes the principle of determination:
Step 1
Tissue Factor + Ca+2
a) Factor VI Factor VIIa
Step 2
Factor Xa
a) Chromogenic substrate Peptide + chromophore
Both steps use commercially available reagents from different suppliers. Although the composition
of these reagents may vary slightly, their essential characteristics are described in the following
specifications.
REAGENTS
The reactive mixture of coagulation factors contains, in particular, purified proteins of human or
bovine origin, specifically Factor X, thromboplastin and Tissue Factor/phospholipid and a Factor VII
activator. These proteins are partially purified and do not contain impurities capable of interfering
with the activation of Factor VII or Factor X. Factor X is present in such quantity that its final
concentration, outside the activation step, is 10 –350 nmole/L, preferably 14 – 70 nmole/L. The
thromboplastin used can be of natural origin (ox or rabbit brain) or synthetic. The thromboplastin
used for the determination of Quick's time is diluted 5 to 50 times in a buffer solution so that the final
concentration of Ca2+ is 15-25 nmole/L. The final stage of Factor Xa formation is carried out in a
solution containing human albumin or bovine albumin at a concentration in which there is no loss in
adsorption and, conveniently, buffered at a pH between 7.3 and 8.0. Factor VII is the only Factor that
limits the formation of Factor Xa in the final incubation mixture and none of the reactive constituents
in the mixture have the power to induce the formation of Factor Xa on their own.
The second step consists of quantifying the Factor Xa formed in the previous step, in a chromogenic
substrate specific for Factor Xa. This substrate is usually a short peptide derived from 3 to 5 amino
acids linked to a chromophore group. The sectioning of this group and the peptide substrate promotes
a shift of the chromophoric activity to a wavelength that allows its quantification by
spectrophotometry. The substrate is usually dissolved in water and used at a final concentration of
0.2 – 2 nmole/L. It may also comprise appropriate inhibitors preventing the further formation of
Factor Xa (iodide addition).
PROCEDURE
Separately, reconstitute the contents of one ampoule of the standard solution and the sample by adding
the required amount of water, and once reconstituted, use them within one hour at most. Add to the
reconstituted preparations the amounts of pre-diluent necessary to obtain solutions of 0.5 –2.0 IU of
Factor VII per milliliter.
Prepare the following dilutions of standard solution and sample with an isotonic buffer solution
without chelating agent, containing 1.0% (w/v) human or bovine albumin, and preferably buffered to
pH 7.3 –8.0. Make from each of the two preparations at least three separate, independent dilutions,
preferably in duplicate. The concentrations of these Factor VII dilutions are adjusted so that the final
concentration is less than 0.005 IU/mL.
Also prepare a control solution containing all the constituent kit of the reactive mixture except for
Factor VII.
All dilutions are prepared in plastic tubes and used in no more than one hour.
Step 1. To each of the dilutions, obtained from the standard and sample solution, add an appropriate
volume of pre-heated coagulation reagent (or a mixture of its separate constituents), homogenize and
incubate at 37°C in plastic tubes or wells of a microplate. The concentration of the different
constituents during the formation of Factor Xa is as specified in reagents. Allow the Factor X
activation reaction to develop for an appropriate time; the end of the reaction takes place, preferably,
before the Factor Xa concentration has reached its maximum level, so that the dose-response curve
presents a satisfactory linearity. The reaction time is also chosen so that the linearity condition of the
Factor Xa production curve as a function of time is satisfactory. It is usually on the order of two to
five minutes, but certain variations are permitted to improve the linearity of the dose-response curve.
Step 2. Stop the activation reaction by adding a reactive mixture containing the chromogenic
substrate. The substrate lysis rate, which is proportional to the Factor Xa concentration, is determined
with the aid of a spectrophotometer by varying the absorbance at an appropriate wavelength. The
absorbance can be determined continuously, which makes it possible to calculate the initial rate of
substrate lysis, either by stopping the hydrolysis reaction after an appropriate time, lowering the pH
with an appropriate reagent such as 50% acetic acid ( w/v) or by a solution of M sodium citrate at pH
3.0. Adjust the hydrolysis time so that the linearity condition for chromophore formation as a function
of time is satisfactory. It is usually on the order of 3 to 15 minutes, but certain variations are permitted
to improve the linearity of the dose-response curve. Check the validity of the titration and calculate
the activity of the sample preparation through the statistical procedures applicable to biological tests
(8).
The International Unit of Factor X corresponds to the activity of a given quantity of the international
standard, which is constituted by a lyophilized concentrate of Factor X of blood coagulation. The
correspondence between the International Unit and the International Standard is indicated by the
World Health Organization.
The chromogenic determination method includes two steps: activation of Factor X by the action of
snake venom and the enzymatic cleavage of a chromogenic substrate by Factor Xa, which releases a
spectrophotometrically quantifiable chromophore. Under appropriate assay conditions, there is a
linear relation between Factor Xa activity and the substrate cleavage.
REAGENTS
Specific X-Factor activator from the Russel's viper venom (RVV): a protein obtained from the venom
of the Russel's viper (Vipera russelli) that specifically activates the X-Factor.
Reconstitute the preparation following the manufacturer’s instructions. Once reconstituted, store at
4°C and use within one month.
Chromogenic substrate for Factor Xa: Factor Xa specific chromogenic substrate such as: N-α-
benzyloxycarbonyl-D-arginyl-L-glycyl-L-arginine-4-nitroanilide, Nbenzoyl-L-isoleucyl-Lglutamyl-
hydrochloride glycyl-L-arginine-4-nitroanilide, methanesulfonyl-D-leucyl-glycyl-L-arginine-4-
nitroanilide, methoxycarbonyl acetate-D-cyclohexylalanyl-glycyl-L-arginine-4-nitroanilide.
Reconstitute following the manufacturer’s instructions.
Dilution buffer: solution containing 0.37% (w/v) tromethamine, 1.8% (w/v) sodium chloride, 0.21%
(w/v) imidazole, 0.002% hexadimethrine bromide (w/v) and bovine albumin, or 0.1% human albumin
(w/v). If necessary, adjust to pH 8.4 with hydrochloric acid.
PROCEDURE
Sample solution: dilute the sample in the Dilution Buffer to obtain a solution containing 0.18 IU of
Factor X per milliliter. Prepare at least three more dilutions of this solution in the Dilution Buffer.
Standard solution: dilute the standard preparation in the Dilution Buffer to obtain a solution
containing 0.18 IU of Factor X per milliliter. Prepare at least three more dilutions of this solution in
the Dilution Buffer. Shortly before testing, place all solutions at 37°C in water bath.
The conditions described apply to the microtitration plates. If the test is carried out in tubes, adjust
the volumes to maintain the proportions in the mixtures.
Introduce 12.5 μL of the different dilutions of Sample Solution and Standard Solution into a series of
wells of the microplate kept at 37 °C. Add 25µL of RVV to each well. Incubate for exactly 90 seconds.
Add to each well 150 µL of Chromogenic Substrate for Factor Xa, diluted six times in Dilution
Buffer. Read the absorbance change rate at 405 nm (5.2.14) and continue for three minutes to obtain
the average rate of absorbance change. If a continuous reading is not possible, determine the
absorbance at 405 nm at standardized consecutive ranges, e.g. every 40 seconds. Plot the linear graph
of the absorbance values versus time and calculate the average rate of change in absorbance. From
the individual values found for each standard and sample dilution, calculate the sample activity and
check the validity of the assay using the usual statistical methods.
The International Unit of Factor VIII corresponds to the activity of a given quantity of the
International Standard, which is constituted by a lyophilized concentrate of Factor VIII of human
blood coagulation. The equivalence of the International Standard with International Units is
established by the World Health Organization (WHO). Human blood coagulation Factor VIII
concentrate is measured in international units against the International Standard. The colorimetric
measurement method consists of two successive steps: the activation of Factor X under the action of
Factor VIII in a reactive mixture of coagulation factors composed of purified substances and the
enzymatic cleavage of a chromogenic substrate by Factor Xa that releases a quantifiable chromophore
by spectrophotometry. Under proper dosing conditions, there is a linear relation between the
formation rate of Factor Xa and the concentration of Factor VIII. The following diagram summarizes
the determination principle:
Step 1
Factor VIII activated
Factor X Factor Xa
Factor IXa, phospholipid, Ca2+
Step 2
Factor Xa
chromogenic substrate peptide + chromophore
Both steps use commercially available reagents. Although the composition of these reagents may vary
slightly, their essential characteristics are described in the following specifications. Deviations from
such specifications may be permitted provided it is demonstrated, using the International Standard,
that the results obtained do not differ significantly. Commercial packaging is used according to
manufacturer’s instructions; it is important to ensure that the packaging chosen is suitable.
The kits used must be properly validated, and in this case, the verification of Factor Xa generation
time may be used to determine the time required to reach 50% of Factor Xa maximum formation.
REAGENTS
The reactive mixture of coagulation factors corresponds to purified proteins of human or bovine
origin, specifically, Factor X, Factor IXa and a Factor VIII activator, usually thrombin. These proteins
are partially purified, preferably minimum 50%, and do not contain impurities capable of interfering
with the activation of Factor VIII or Factor X. Thrombin may be present in the form of its precursor,
prothrombin, as long as its activation in reactive mixture is fast enough to allow complete and nearly
instantaneous activation of Factor VIII in the assay. The reactive mixture must contain phospholipids
that can be of natural origin (for example: brain, bovine spinal cord and soy extract) or obtained
artificially, consisting of about 15 to 31% of phosphatidylserine. The final concentration of
phospholipids during the Factor Xa formation step is approximately 10 to 35 µmole/L. The reactive
mixture also contains calcium ions in such quantity that its final concentration is 5 to 15 mmole/L.
The final stage of Factor Xa formation is carried out in a solution that must contain minimum 1
mg/mL of conveniently buffered human or bovine albumin (pH 7.3 to 8.0). The different constituents
of the reactive medium are usually brought together in two separate preparations, which alone should
not induce the formation of Factor Xa. After reconstitution, these two preparations can be combined
provided that no amounts of Factor Xa are formed in the absence of Factor VIII. Factor VIII is the
only factor that limits the formation of Factor Xa in the final incubation mixture. The second step
consists of quantifying the Factor Xa formed in the previous step in a chromogenic substrate specific
for Factor Xa. This substrate is usually a short peptide derived from 3 to 5 amino acids bonded to a
chromophore group. The sectioning of this group and the peptide substrate promotes a shift of the
chromophoric activity to a wavelength that allows its quantification by spectrophotometry. The
substrate, usually dissolved in water and used in a final concentration of 0.2 to 2 mmole/L, must
contain the appropriate inhibitors to prevent the additional formation of Factor Xa and suppress all
thrombin activity, which enables to improve the assay selectivity in the presence of Factor Xa.
PROCEDURE
The entire content of an ampoule of the Standard Solution and the Sample Solution must be
reconstituted by adding the amount of water and use immediately. Add amounts of pre-diluent
necessary to obtain solutions between 0.5 to 2.0 IU/mL. The pre-diluent consists of plasma from a
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.1-00
donor with severe hemophilia A, or from an artificially prepared reagent, providing results equivalent
to those obtained with hemophilic plasma and with the same standard and sample preparations. Pre-
diluted solutions must present good stability beyond the time required for determination of at least 30
minutes at 20°C and be used within 15 minutes. Make the following dilutions of the standard and
sample preparation using an isotonic buffer solution without a chelating agent, and containing 1.0%
human or bovine albumin; the solution may contain, for example, tromethamine or imidazole and is
preferably buffered (pH 7.3 to 8.0). Prepare at least three additional independent dilutions, preferably
in duplicate. The solutions must be prepared in such a manner that the final Factor VIII concentration,
apart from the Factor Xa formation stage, is less than 0.03 UI/mL and preferably than 0.01 UI/mL.
Prepare a standard containing all the constituent kit of the reactive mixture except for Factor VIII.
Prepare dilutions in plastic tubes and use immediately.
Step 1. To each of the dilutions, obtained from the standard and sample solution preparation, add an
appropriate volume of pre-heated coagulation reagent (or a mixture of its separate constituents),
homogenize and incubate at 37°C in plastic tubes or wells of a microplate. Allow the Factor X
activation reaction to develop for an appropriate time; the end of the reaction takes place, preferably,
before the Factor X concentration has reached its maximum level, so that the dose-response curve
presents a satisfactory linearity. The reaction time is also chosen so that the linearity condition of the
Factor Xa production curve as a function of time is satisfactory. It is usually on the order of two to
five minutes, but certain variations are permitted to improve the linearity of the dose-response curve.
Step 2. Interrupt the activation reaction by adding a reactive mixture containing the chromogenic
substrate. The substrate lysis rate, which is proportional to the Factor Xa concentration, is determined
by a spectrophotometer by varying the absorbance at an appropriate wavelength. The absorbance can
be determined continuously, which makes it possible to calculate the initial rate of substrate lysis,
either by interrupting the hydrolysis reaction after an appropriate time, lowering the pH with an
appropriate reagent such as acetic acid (50% v/v of C2H4O2) or by a M citrate buffer at pH 3.0. Adjust
the hydrolysis time so that the linearity condition for chromophore formation as a function of time is
satisfactory. It is usually on the order of 3 to 15 minutes, but certain variations are permitted to
improve the linearity of the dose-response curve. Check the validity of the test and calculate the
activity of the sample through statistical procedures applicable to biological tests.
Immediately transfer 0.1 mL of a 0.37% (w/v) calcium chloride solution to each tube, previously
heated to 37°C, and determine the time range between the addition of the calcium chloride solution.
calcium and clot formation, this determination is carried out within 30 minutes following the first
dilution. The assay is only valid if the blank clotting time is 200 to 350 seconds.
Prepare a serial duplicate dilution of the preparation to be examined in 0.9% (w/v) sodium chloride
solution. For each dilution of a series, add a volume equal to 5.0% (v/v) of the group A1 red cell
suspension. Red blood cells must be previously washed three times in a sodium chloride solution. For
each dilution of the other series, add an equal volume of 5.0% (v/v) of the group B red cell suspension.
The red cells must be previously washed three times in a 0.9% (w/v) sodium chloride solution ).
Incubate the dilution series at 37°C for 30 minutes and then wash three times with 0.9% sodium
chloride (w/v). Leave the red cells in contact with the polyvalent human antiglobulin reagent for 30
minutes. Without centrifuging, examine each suspension for agglutination under a microscope.
Nucleic acid amplification methods were established based on two different principles:
a) amplification of a target nucleic acid sequence using polymerase chain reaction (PCR), ligase
chain reaction (LCR), or isothermal amplification of a ribonucleic acid (RNA) sequence;
b) amplification of a hybridization signal for deoxyribonucleic acid (DNA) using the branched DNA
method (bDNA), for example. In this case, signal amplification takes place without subjecting the
nucleic acid to repetitive amplification cycles.
Generally speaking, the PCR method is described as the reference method. Alternative methods can
be used, provided they meet the quality requirements and are properly validated.
APPLICATION FIELD
Establish the requirements for sample preparation, amplification of DNA sequences, and specific
detection of the PCR reaction product. PCR enables detection and amplification of defined DNA and
RNA sequences (after their reverse transcription into complementary DNA – cDNA).
METHOD PRINCIPLE
PCR is the fundament of a method that enables the specific in vitro amplification of DNA or RNA
segments. After denaturation of the double strand of DNA into single strands of DNA, two synthetic
oligonucleotide primers, of opposite polarity, hybridize with their respective complementary
sequences in the DNA to be amplified. In this case, the activity of the primers makes it possible to
complete the single strand of DNA, giving rise to short, biquaternary sequences that surround the
DNA fragment to be amplified; thus serving as a starting point for DNA synthesis. It should be noted
that this process is carried out through the action of a thermostable DNA polymerase.
Repeated cycles of heat denaturation, primer hybridization and DNA synthesis give rise to an
exponential amplification of the DNA fragment then delimited by the primers. The specific product
of the PCR reaction, known as an amplicon, can be detected using a variety of methods of appropriate
specificity and sensitivity. The Multiplex PCR assay uses several pairs of primers, intended for
simultaneous amplification for different targets of a reaction.
TEST MATERIAL
Due to PCR great sensitivity, samples must be protected from the incidence of light and any external
contamination. The sampling, conservation and transport of the material to be analyzed must be
carried out under conditions capable of minimizing the risks of degradation of the sequence to be
amplified. In tagged RNA sequences, special precautions must be taken since RNA is very sensitive
to degradation by ribonucleases, as well as to some additives (anticoagulants and preservatives) that
may interfere with the assays.
PROCEDURE
Contaminant Prevention
The risk of contamination requires the existence of restricted areas, depending on the nature of the
materials and technology used. Points to consider include: personnel flow, work flow, material
handling, ventilation systems, and decontamination procedures.
Sample preparation
Sample preparation consists of extracting or releasing the target sequence to be amplified from the
material to be examined. The method used for this purpose must be effective, reproducible and
compatible with the amplification under the selected reaction conditions. A variety of
physicochemical methods for extraction and/or enrichment can be used.
Potential additives in the material under analysis may interfere with the PCR method. The procedures
described in the Internal Control item must be used to verify the absence of inhibition factors in the
material to be examined.
As for the RNA models, precautions must be taken so that there is an absence of ribonuclease-like
activity.
Amplification
Amplification of a target sequence by PCR method requires, minimum, a pair of primers, the four
types of triphosphate deoxynucleotides (dNTPs), magnesium ions (MgCl2), and a thermostable DNA
polymerase for DNA synthesis.
Amplification of the target sequence by PCR is conducted under defined cyclic conditions:
temperature profile for DNA double-stranded denaturation; annealing and extension of primers and
incubation times at selected temperatures within a range.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.1-00
Detection
The generated amplified sequence can be identified: by its size, sequence, chemical modification or
a combination of these parameters. Detection and characterization by size can be performed by gel
electrophoresis (using agarose gel plates, or polyacrylamide gel plates, or by capillary
electrophoresis), or by column chromatography (for example, HPLC - High performance liquid
chromatography)). Detection and characterization by sequence composition can be carried out by
specific hybridization with probes complementary to the target sequence or by fragmentation of the
amplified material by means of a restriction enzyme at specific sites of the sequence to be amplified.
Characterization through chemical modification can be performed by incorporating a fluorophore in
the labeled sequences and subsequent excitation and detection of fluorescein. Labeled probes that
enable subsequent radioisotopic or immunoenzymatic detection can also be used.
An assay result is only valid if the positive control(s) is(are) unequivocally positive and the negative
control(s) is(are) unequivocally negative. Due to the PCR method high sensitivity and the inherent
risks of contamination, it is necessary to confirm positive results by performing the assay in duplicate
or, when possible, with a new aliquot of the sample. The sample is considered positive if at least one
of the repeated tests is positive.
QUALITY ASSURANCE
The validation program must include the devices and the PCR method used. As references
recommendations from the ICH (The International Conference on Harmonization of Technical
Requirements for Registration of Pharmaceuticals for Human Use) should be used: Q2B, Analytical
Method Validation, or equivalent alternative reference.
It is essential to carry out this validation using official biological reference standards, properly
calibrated using International Standards for the target sequences used in the assay.
Validation must include the determination of the positive response threshold, that is, the minimum
number of labeled sequences per volume unit that can be detected in not less than 95% of the assays.
This value depends on several interrelated factors, such as: the volume of the sample submitted to
extraction and the efficiency of the extraction method; the transcription of tagged RNA into
complementary DNA; the amplification procedure and the detection system. To define the detection
limit of the system used, it is necessary to consider the positive response threshold for each sequence
to be amplified and the assay operating characteristics with the respective maximum and minimum
limits of the positive response.
All crucial reagents used in the methodology put into practice must be subject to control before their
routine use. Acceptance/rejection must be based on pre-defined quality criteria. Primers are one of
the essential components of the PCR method, thus requiring particular attention to their design; purity
and validation of their use in the assay. Each new batch of initiators should be checked for specificity;
amplification efficiency and absence of inhibitory impurities. Primers can be modified (for example,
by conjugation with a fluorophore, or an antigen) so as to allow the use of a specific method of
detection of the target sequence to be amplified; provided that those modifications do not inhibit the
precision and effectiveness of amplification of the target sequence.
ASSAY CONTROLS
External controls
To detect any contamination and ensure adequate sensitivity, the following external controls should
be included in all PCR assays:
- a positive control with a defined number of copies of the target sequence, that number being
specifically determined for each assay system and expressed as a multiple of the positive response
threshold of the system in question;
- a negative control consisting of a matrix sample that was shown to be free of target sequences.
Internal control
The internal control is formed by defined nucleotide sequences containing the primer binding sites.
Internal control must be amplified with defined effectiveness and products must be clearly
discernible. This internal control must belong to the same type of nucleic acid (DNA/RNA) as the
sample. The internal control is preferably added to the sample prior to nucleic acid isolation and
therefore acts as a global control (extraction, reverse transcription, amplification and detection).
For each laboratory and each operator, participation in external quality assessment programs is an
important aspect of quality assurance in PCR.
and may even be considered as limit assays for the control of impurities. These recommendations
describe the methods for validating nucleic acid amplification methods applicable only to qualitative
assays designed to detect HCV RNA in plasma mixtures. Therefore, the two validation parameters
considered to be the most important are specificity and detection limit. Robustness is also evaluated.
However, this document can also be used as a basis for general validation of amplification methods.
This document defines the analytical method as the set of operations performed after nucleic acid
extraction, followed by detection of amplified products. It should be noted that in cases of use of
commercial kits, as part of the complete analytical procedure, the documented validation
considerations already carried out by the manufacturer can replace the validation by the operator.
However, performance of the traded kit related to its intended use has to be demonstrated by the user
(e.g. detection limit, robustness and cross contamination).
SPECIFICITY
Specificity is the ability to unambiguously assess nucleic acid in the presence of components of
unexpected presence. The specificity of analytical nucleic acid amplification procedures is dependent
on the choice of primers, the choice of probe (for analysis of the final product) and the strictness of
test conditions (for both the amplification and detection steps).
In the design of primers and probes, one of the aspects to be considered is their specificity in detecting
HCV RNA; for this fact it is convenient to compare the target sequences with the sequences published
in databases. For HCV, primers and probes are usually chosen from the areas of the 5' non-coding
region (5'NCR) of the HCV genome, composed of 341 nucleotides, which are the most conserved
among the different HCV isolates.
The amplified product must be unambiguously identified by the use of methods such as: amplification
with stranded primers, restriction enzyme analysis, sequencing, or hybridization with a specific probe.
To validate the specificity of the analytical method, it is convenient to test minimum 100 plasma
mixtures negative for HCV RNA, and all results obtained are negative. The World Health
Organization (WHO) has suitable samples of non-reactive plasma.
The method capability to detect all HCV genotypes will depend on the choice of primers, probes and
operating parameters. This capability should be demonstrated through the use of a collection of
characterized reference preparations.
It has been suggested that the distribution pattern of HCV genotypes in Brazil is similar to that found
in many European countries, with the prevalence of types 1 and 3. There is an epidemiological
behavior typical of an exponential spread in recent years, probably as a result of blood transfusions.
In this context, genotypes 1 and 3 must be detected at appropriate levels.
DETECTION LIMIT
The detection limit of an individual method is the smallest amount of nucleic acid that can be detected,
but not necessarily quantified, with an exact value in the sample.
The amplification process used to detect HCV RNA in plasma mixtures generally provides qualitative
results. The number of possible results is limited to two answers: positive or negative. Although
determination of the detection limit is recommended, for practical reasons, the positive response
threshold for nucleic acid amplification methods is determined. The positive response threshold is the
minimum number of target sequences per unit volume that can be detected in 95% of assays. This
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.1-00
positive response threshold is influenced by the distribution of viral genomes in the individual
samples tested and by factors such as enzyme efficacy, which can lead to differences of 95% in the
positive response thresholds obtained in the individual analysis.
To determine the positive response threshold, it is essential to perform the method on different days
with a series of dilutions of a working reagent or Hepatitis C virus (biological reference standard),
calibrated against the International Standard for HCV 96/ 790 WHO to evaluate among the various
assays. A minimum of three separate dilution series are tested with a sufficient number of replicates
of each dilution to obtain a total number of 24 results per dilution, thus allowing for statistical analysis
of the results.
For example, in a laboratory, three series of dilutions are tested with eight replicates for each dilution
on different days; four dilution series with six replications for each dilution on different days, or six
dilution series with four replications for each dilution on different days.
For the number of dilutions used to remain the same, it is essential to carry out a preliminary test
(such as, for example, logarithmic dilutions in the sample of the plasma mixture to obtain a
preliminary positive response threshold value, i.e., the highest dilution in which a positive sign
occurs).
The distribution of dilutions can then be performed based on this pre-calculated preliminary value
(using, for example, a 0.5 log dilution factor), or less than a mixture of negative plasma as the dilution
matrix. The RNA content of HCV that can be detected is 95% in the assays and can be calculated
using an appropriate statistical method. These results, also, serve to demonstrate the internal variation
of the assay and the variation in several days of the analytical method.
ROBUSTNESS
The robustness of an analytical method is the measure of its ability to remain unchanged when subject
to small but deliberate variations in operating parameters and provides an indication of the method
feasibility under normal conditions of use. Robustness assessment is one of the aspects to be
considered during the development phase. It enables establish the method feasibility under deliberate
variations in operating parameters. In nucleic acid amplification methods, small variations in
operating parameters may be of special importance. However, robustness can be demonstrated during
method development, when small variations in the concentration of reagents are tested (for example:
MgCl2, primers or dNTPs). To demonstrate robustness during validation, at least twenty plasma
mixtures (randomly chosen) negative for HCV RNA should be examined to which a final typical
concentration corresponding to the positive response threshold is added, previously, determined. All
results obtained are positive.
Problems with robustness can arise in methods that use, in their initial phase, ultracentrifugation prior
to the extraction of viral RNA. Therefore, to test the robustness of these methods. At least twenty
plasma mixtures containing varying concentrations of HCV RNA but free of HCV-specific antibodies
are tested. All results obtained are positive.
QUALITY ASSURANCE
Biological assay methods, such as the nucleic acid amplification method, may present specific
problems that interfere with the validation and interpretation of results.
Procedures must be described precisely in the form of standard operating procedures (SOPs), which
must cover:
- sampling (type of containers, etc.);
- preparation of mini-mixtures (if applicable);
- storage conditions prior to analysis;
- exact description of the operating conditions (including precautions that must be taken to avoid
cross-contamination or destruction of the viral RNA) as well as the standard reagents and
preparations used;
- Detailed formulas for calculating results, including statistical evaluation. The use of appropriate
control (e.g., appropriate dilution of hepatitis C virus, biological reference standard; or plasma to
which a calibrated HCV sample has been added against the HCV International Standard 96/790
from WHO) it can be considered a satisfactory stable means of controlling the system and ensuring
and maintaining the method feasibility in each use.
Technical qualification: for each critical element of the apparatus used, an appropriate installation
and operational qualification program is created. After any modification of critical equipment (for
example, thermal cyclers) it is essential to reconfirm the method acceptability, proceeding in parallel
with the examination of eight samples of a plasma mixture to which was added a triple concentration
of HCV RNA of that corresponding to the previously determined positive response threshold; all
results obtained are positive.
Operator qualification: an appropriate qualification program is developed for the set of operators
involved in the test. For this purpose, each operator should examine at least eight samples of a plasma
mixture to which a triple HCV RNA concentration corresponding to the previously determined
positive response threshold has been added. This test (eight samples) is repeated twice on different
days for a total of twenty-four analysis carried out on three different days. All results obtained are
positive.
REAGENTS
Buffer A
Tromethamine 6.055 g
Sodium chloride 1.170 g
Hexadimethrin Bromide 50 mg
Sodium Azide 0.100 g
Dissolve the reagents in water, adjust pH to 8.0 with 2 M hydrochloric acid and adjust to 1000 mL
with water.
Buffer B
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.1-00
Tromethamine 6.055 g
Sodium chloride 8.770 g
Dissolve the reagents in water, adjust pH to 8.0 with 2 M hydrochloric acid and adjust to 1000 mL
with water.
Blood or plasma used in the preparation of prekallikrein should be collected and handled only in
plastic or silicone glass materials in order to avoid activation of prekallikrein resulting from clotting.
Homogenize nine volumes of human blood with one volume of anticoagulant solution (ACD, CPD
or a 38 g/L sodium citrate solution) added with 1 mg per milliliter of hexadimethrine bromide. Shake
and centrifuge at 3600 g for five minutes. Separate plasma and centrifuge at 6000 g for 20 minutes
to separate platelets. Separate the platelet-poor plasma and dialyze against 10 volumes of Buffer A
for 20 hours. After dialysis, deposit the plasma on a chromatography column containing twice its
volume of agarose-DEAE for ion exchange chromatography previously equilibrated with Buffer A.
Carry out elution with Buffer A (flow rate 20 mL/cm2/hour). Collect the eluate in fractions and record
the absorbance at 280 nm (5.2.14). Join the fractions containing the first protein peak so as to obtain
a volume approximately 1.2 times that of platelet-poor plasma.
To verify that the substrate does not have active kallikrein, homogenize a volume with 20 volumes
of chromogenic substrate solution that will be used in the assay, previously heated at 37°C, and keep
the mixture at 37°C for two minutes. Substrate is suitable if absorbance does not increase by more
than 0.001 per minute. Add 7 g per liter of sodium chloride to the substrate solution and filter through
a membrane (0.45 μm). Freeze the filtrate after partitioning it into aliquots and store at -25°C; it is
also possible to lyophilize the filtrate before storage. Carry out the operations between
chromatography and congealing the aliquots on the same day.
TITRATION
Preferably, titration is carried out on an automated enzyme analyzer at 37°C. Adjust volumes,
substrate concentration and incubation times so that the reaction rate is linear to not less than 35 IU
per milliliter. If necessary, the standards, samples and prekallikrein substrate can be diluted with
Buffer B.
Incubate standards or diluted samples with prekallikrein substrate for 10 minutes; the volume of
standard or sample before dilution does not exceed 1/10 of the total volume of the mixture to be
incubated to avoid errors resulting from differences in ionic strength or pH. Incubate the mixture or
a portion of the mixture with an equal or higher volume of a solution of a known specific chromogenic
substrate for kallikrein (e.g. N-benzoyl-L-prolyl-L-phenylalanyl-L-arginine acetate 4-nitroanilide or
D-propyl-L-phenylalanyl-L-arginine 4-nitroanilide dihydrochloride) and dissolved in Buffer B.
Record the change in absorbance per minute (ΔA/minute) for 2 to 10 minutes at the appropriate
wavelength for the substrate used. For each standard or sample mix, prepare a blank by replacing the
prekallikrein substrate with Buffer B. Correct the change in absorbance per minute by subtracting the
value obtained with the corresponding blank. Plot a calibration curve from the values of the change
in absorbance per minute obtained with the standard and its respective concentrations and determine
the prekallikrein activation content of the sample.
added to a thrombin and residual thrombin activity is determined with an appropriate chromogenic
substrate.
The International Unit corresponds to the activity of a specified amount of the International Standard
for human antithrombin III concentrate. The equivalence of the International Unit with the
International Standard is indicated by the World Health Organization.
PROCEDURE
For the sample and the standard, prepare with Tris-EDTA ASB buffer pH 8.4 containing 15 IU of
heparin per milliliter, two independent series of three or four dilutions between 1/75 and 1/200 starting
from 1 IU /mL. Heat at 37 °C for one to two minutes 200 μL of each dilution. Add to each dilution
200 μL of a bovine thrombin solution containing 2 IU/mL in Tris-EDTA ASB buffer pH 8.4.
Homogenize and keep at 37°C for exactly one minute. Add 500µL of an appropriate chromogenic
substrate (e.g. D-phenylalanyl-L-pipecolyl-L-arginine-4-nitroanilide; dissolve the substrate in water
to obtain a solution containing 4 mmole/L and dilute with Tris-EDTA buffer ASB pH 8.4 without
albumin to a concentration appropriate for the titration assay). Immediately determine absorbance at
405 nm (5.2.14) for at least 30 seconds. Calculate the change in absorbance (ΔA/minute). An endpoint
titration can also be used by interrupting the reaction with acetic acid and determining the absorbance
at 405 nm. The change in absorbance (ΔA/minute) is inversely proportional to the activity of human
antithrombin III. Check the validity of the test and calculate the activity of the sample through the
statistical procedures applicable to biological tests.
The hemolytic unit of complementary activity (CH50) is the amount of complement that, under the
stipulated reaction conditions, causes the lysis of 2.5 x 108 of a total number of 5 x 108 properly
sensitized red cells
REAGENTS
Magnesium and calcium stock solution. Weigh 1.103 g of calcium chloride and 5.083 g of magnesium
chloride, dissolve in water and adjust to 25 mL with the same solvent.
Barbital buffer stock solution. Weigh 207.5 g of sodium chloride and 25.48 g of sodium barbital,
dissolve in 4000 mL of water and adjust pH to 7.3 with M hydrochloric acid. Add 12.5 mL of
Magnesium and calcium stock solution and adjust to 5000 mL with water. Filter through membrane
(0.22 μm) and store at 4 °C in a glass container.
Gelatin solution. Weigh 12.5 g of gelatin, dissolve in about 800 mL of water and heat to boiling in
water bath. Cool to 20°C and adjust to 10 liters with water. Filter through membrane (0.22 μm) and
store at 4 °C. Only use the solution if it is clear without fractioning.
Citrated solution. Weigh 8 g of sodium citrate, 4.2 g of sodium chloride and 20.5 g of glucose and
dissolve in 750 mL of water. Adjust pH to 6.1 with 10% (w/v) citric acid solution and adjust to 1000
mL with water.
Barbital gelatin buffer. Add four volumes of Gelatin Solution to one volume of Barbital Buffer Stock
Solution and homogenize. If necessary, adjust the pH to 7.3 with M hydrochloric acid or M sodium
hydroxide and store at 4°C. Prepare a new solution daily.
Stabilized sheep blood. Collect one volume of sheep blood in one volume of Citrated Solution and
homogenize. Store blood stabilized at 4°C for not less than seven days and not more than 28 days.
Sheep blood or stabilized sheep erythrocytes are commercially available from a variety of suppliers.
Hemolysin. Sheep anti-erythrocyte serum, prepared in rabbits. Such sera are commercially available
from a variety of suppliers.
Guinea pig complement. Homogenize the sera obtained from at least 10 guinea pigs. Separate serum
from clotted blood by centrifugation at a temperature of about 4°C. Store the serum, in small portions,
at a temperature below -70 °C.
PROCEDURE
Separate sheep red blood cells by centrifugation of an appropriate volume of stabilized sheep blood;
wash the cells at least three times with Gelatin Barbital Buffer and prepare a 5.0% (v/v) suspension
in the same buffer. Determine cell concentration by the following method: add 0.2 mL of the
suspension to 2.8 mL of water and centrifuge the lysate for five minutes at 1000 g. Cellular
concentration is adequate if the supernatant absorbance (5.2.14), determined at 541 nm, is 0.62 ±0.01.
Correct the cell concentration by adding Gelatin-Barbital Buffer, according to the formula:
𝑉𝑖 × 𝐴
𝑉𝑓 =
0,62
where
Vf = final volume;
Vi = initial volume;
A = absorbance determined at 541 nm for the original suspension.
Once the cell concentration is adjusted, the suspension contains about 1 x 109 cells per milliliter.
Hemolysin Titration
Transfer 1 mL of the 5.0% sheep red blood cell suspension to each tube of the hemolysin dilution
series from the 1/75 dilution and homogenize. Incubate at 37°C for 30 minutes. Transfer 0.2 mL of
each incubated hemolysin dilution mixture to new tubes and add 1.1 mL of Barbital Gelatin Buffer
and 0.2 mL of a guinea pig complement dilution (e.g. 1/150). Carry out these manipulations in
duplicate.
Prepare three control tubes of non-hemolyzed cells, transferring 1.4 mL of Barbital Gelatin Buffer
and 0.1 mL of 5.0% sheep red blood cell suspension into each one.
Prepare three control tubes of fully hemolyzed cells by transferring 1.4 mL of water and 0.1 mL of
the 5.0% sheep erythrocyte suspension to each tube.
Incubate all tubes at 37°C for 60 minutes and centrifuge at 1000 g for five minutes. Determine the
absorbance (5.2.14) of the supernatants at 541 nm and calculate the percentage of hemolysis occurring
in each tube using the formula:
𝐴𝑎 − 𝐴1
× 100
𝐴𝑏 − 𝐴1
where
Plot a graph containing the hemolysis percentages on the ordinate axis and the inverses of hemolysin
dilutions on the abscissa axis. Determine the optimal hemolysin dilution from the graph by choosing
a dilution such that an increase in the hemolysin amount does not produce a meaningful change in the
hemolysis degree. This dilution is considered to contain 1 minimal hemolytic unit (1 MHU) in 1.0
mL. For the preparation of sensitized sheep red blood cells, the hemolysin dilution corresponding to
the optimal hemolysis contains 2 MHU per milliliter.
Hemolysin titration is only valid if the degree of total hemolysis is between 50% and 70%. If the
percentage of total hemolysis cannot be determined from the dilution used, repeat the titration using
a more or less diluted complement solution.
Optimum preparation of sensitized sheep red blood cells (hemolytic system). Prepare an appropriate
amount of diluted hemolysin containing 2 UHM per milliliter and an equal volume of 5.0%
standardized sheep erythrocyte suspension. Add hemolysin dilution to the standardized cell
suspension and homogenize. Incubate at 37°C for 15 minutes, store at 2°C to 8°C and use within six
hours.
Complement titration
Prepare an appropriate dilution of complement (e.g. 1:250) using Gelatin-Barbital Buffer and carry
out the titration, in duplicate, according to the information recorded in Table 2.
To each tube, add 0.2 mL of sensitized sheep erythrocytes, homogenize thoroughly and incubate all
tubes at 37°C for 60 minutes. Cool tubes in ice water and centrifuge at 1000 g for five minutes.
Determine the absorbance of the supernatants at 541 nm and calculate the percentage of hemolysis
(Y), using the formula:
𝐴𝑐 − 𝐴1
× 100
𝐴𝑏 − 𝐴1
where
Plot a graph by entering the values in abscissa, and the corresponding volume in milliliters of diluted
complement in ordinates.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.1-00
From the points, plot the ideal line and determine the ordinate of the hemolytic activity at 50% of the
complement at the point where Y/(1–Y) = 1.0. Calculate the activity in terms of hemolytic units (CH
50 /mL) according to the formula:
𝐶𝑑
×5
𝐶𝑎
where
Cd = inverse value of the complement dilution,
Ca = volume in milliliters of diluted complement that produces 50% hemolysis,
5 = Scale factor to account for the number of erythrocytes.
The test is only valid if, between 15 and 85% of hemolysis, the curve obtained is a straight line whose
slope is between 0.15 and 0.40, preferably between 0.18 and 0.30.
Dilute the titrated guinea pig complement with Gelatin-Barbital Buffer to obtain 100 CH50/mL. If
necessary, adjust the sample to pH 7.0. For an immunoglobulin containing 50 mg/mL, prepare the
incubation mixtures (Table 3).
Carry out the determination on the sample and prepare the AAC negative and positive control from a
human immunoglobulin international standard, according to the instructions provided on the label for
the standard preparation. If the sample does not contain 50mg/mL of immunoglobulin, adjust the
volumes of the preparation and the Gelatin Barbital Buffer; for example, pipette 0.33 mL of a
preparation containing 30 mg/mL of immunoglobulin and add 0.47 mL of Gelatin-Barbital Buffer to
obtain the same total volume of 0.8 mL. Close tubes and incubate at 37°C for 60 minutes. Add 0.2
mL of each incubation mixture to 9.8 mL of Gelatin Barbital Buffer to dilute the complement. In each
tube, carry out complement titrations as described above to determine residual anti-complementary
activity (Table 2). Calculate the anti-complementary activity of the sample, by reference to the
complement control considered as 100%, according to the formula:
𝑎−𝑏
× 100
𝑎
where
a = average complementary activity (CH50/mL) of controls,
b =complementary activity (CH50/mL) of the sample.
Proteins in solution absorb ultraviolet light at a wavelength of 280 nm, due to the presence in their
structure of aromatic amino acids (especially tyrosine and tryptophan), a property that can be used
for protein assay. The use of a buffer as compensation liquid can remedy the interference produced
in case the buffer used to dissolve the protein has high absorbance, which could compromise the
results. At low concentrations, the protein adsorbed onto the curve can cause a significant decrease
in the protein content of the solution. It is possible to prevent this phenomenon by preparing high-
grade samples or using a non-ionic detergent during preparation.
Sample solution. Dissolve an appropriate amount of the sample in the chosen buffer to obtain a
solution whose protein concentration is between 0.2mg/mL and 2mg/mL.
Standard solution. Prepare a solution of the appropriate reference substance corresponding to the
protein to be dosed, in the same buffer as used for the sample solution, so as to obtain the same
concentration.
Procedure. Keep the sample solution, standard solution and compensation liquid at the same
temperature throughout the test. Determine the absorbance (5.2.14) of the sample solution and the
standard solution at 280 nm in quartz cuvettes, using the specific buffer as the compensation liquid.
For the accuracy of the results, the response is linear over the range of protein concentrations to be
dosed.
Light diffusing. Light diffusing through the sample can affect the accuracy of protein assay. If the
proteins in solution form particles whose size is of the same magnitude as the wavelength of the
measuring beam (250 –300 nm), the diffusion of the light beam translates into an increase in the
apparent absorbance of the sample. To calculate the contribution of this diffusion effect on the
absorbance read at 280 nm, determine the absorbance of the sample solution at various wavelengths
(320 nm, 325 nm, 330 nm, 335 nm, 340 nm, 345 nm and 350 nm). Plot a graph of the absorbance log
read as a function of the log of the respective wavelength and determine, by linear regression analysis,
the calibration curve that best fits the different points inserted on the graph.
Determine by extrapolation the absorbance log at 280 nm. The absorbance due to the diffusion effect
is the antilog of this value. Correct the observed values by subtracting the total absorbance at 280 nm
from the absorbance due to the diffusion effect to obtain the absorbance value from the protein in
solution. It is possible to carry out a filtration using a 0.2 μ filter that does not absorb the proteins, or
a clarification by centrifugation, to reduce the effects of light scattering in a solution.
Calculations Use corrected values for calculations. Calculate the protein content of the sample
solution (Cu), using the expression:
𝐴𝑢
𝐶𝑢 = 𝐶𝑠 ( )
𝐴𝑠
where
CS = protein content of the standard solution;
Au = corrected absorbance value of the sample solution;
AS = corrected absorbance value of the standard solution;
METHOD 2
This method was conceived based on the property that proteins have to reduce phosphomolybdenum
tungsten acids contained in the phosphomolybdenum and tungsten reagent; this reaction is
chromogenic and translates into the existence of an absorption peak at 750 nm.
Phosphomolybdenum and tungsten reagent react primarily with protein tyrosine residues. Color
production reaches a maximum after 20 – 30 minutes of incubation at room temperature; then
progressive discoloration takes place. Since the method is sensitive to interfering substances, a
treatment that produces precipitation of the proteins in the sample can be used. Most interfering
substances reduce the intensity of the color obtained, but some detergents increase it slightly. A strong
salt concentration can form a precipitate. Since the intensity of the color obtained may vary depending
on the protein species considered, the protein to be dosed and the standard protein are the same. If
necessary, separate interfering substances from sample protein, proceed as follows on interfering
substances before preparing the sample solution. It is possible to minimize the effect of interfering
substances by dilution, as long as the protein content to be determined remains high enough to allow
for an accurate determination.
Use distilled water for the preparation of all buffers and reagents used in this method.
Sample solution. Dissolve an appropriate amount of the sample in the specified buffer to obtain a
concentration within the range covered by the calibration curve. The pH of a solution prepared with
an appropriate buffer is between 10.0 and 10.5.
Standard solutions. Dissolve the reference substance corresponding to the protein to be dosed in the
specified buffer. Take samples of this solution and adjust with the same buffer to obtain at least five
standard solutions of different concentrations between 5μg/mL and 100μg/mL and evenly distributed
over the chosen range.
Blank solutions. Use the same buffer that was used to prepare the Sample Solution and Standard
Solutions.
Copper Sulfate Reagent. Weigh 100 mg of copper sulphate and 0.2 g of sodium tartrate, dissolve in
distilled water and adjust to 50 mL with the same diluent. Weigh 10 g of anhydrous sodium carbonate,
dissolve in distilled water and adjust to 50 mL with the same diluent. Slowly pour the sodium
carbonate solution into the copper sulphate solution, always mixing. This solution is used within 24
hours of its preparation.
Copper alkaline reagent. Prepare a mixture of one volume of Copper Sulfate Reagent, two volumes
of 5.0% (w/v) sodium lauryl sulfate with one volume of 3.2% (w/v) sodium hydroxide. Store this
mixture at room temperature. The mixture is used within two weeks upon preparation.
Procedure. To 1 mL of each Standard Solution, Sample Solution and Blank Solution add 1 mL of
Alkaline Copper Reagent and homogenize. Allow to stand for 10 minutes. Add 0.5 mL of diluted
Tungsten and Phosphomolybdenum Reagent, homogenize and allow to stand at room temperature for
30 minutes.
Determine the absorbance (5.2.14) of the solutions at 750 nm, using the blank solution for zero
adjustment.
Calculations The relation between absorbance and protein content is not linear; however, if the
concentration range covered by the calibration curve is sufficiently narrow, the curve obtained will
be substantially linear. Plot the absorbance of standard solutions against the protein content of these
solutions and determine the calibration curve by linear regression analysis. From the calibration curve
and the absorbance of the sample solution, determine the protein content of the sample solution.
Interfering substances. In this method, sodium deoxycholate and trichloroacetic acid are added to the
sample to precipitate the proteins and separate them from interfering substances, before dosing. This
method can also be used to concentrate proteins contained in a very dilute solution. To 1 mL of a
sample solution add 0.1 mL of 0.15% sodium deoxycholate (w/v). Homogenize with a vortex shaker
and allow to stand at room temperature for 10 minutes. Add 0.1 mL of 72% (w/v) trichloroacetic acid.
Homogenize with a vortex mixer and centrifuge at 3000 g for 30 minutes. Discard the liquid
supernatant and discard the residual liquid with a pipette. Dissolve the clot in 1 mL of Alkaline Copper
Reagent.
METHOD 3
This method was based on the property that proteins have to shift from 470 nm to 595 nm the
maximum absorption of acid blue 90 when they bind to the dye. The acid blue 90 dye has a marked
affinity for arginine and lysine residues in the protein which can cause variations in the response to
the assay of different proteins. The protein used as the reference substance must therefore be the same
as the protein to be dosed. There are relatively few interfering substances, but it is preferable to avoid
detergents and analytes in the sample to be dosed. Highly alkaline samples can interfere with the acid
reagent.
Use distilled water for the preparation of all buffers and reagents to be used in this method.
Sample solution. Weigh an appropriate amount of sample and dissolve in the indicated buffer to obtain
a concentration within the range covered by the calibration curve.
Standard solutions. Weigh the reference substance corresponding to the protein to be dosed and
dissolve in the indicated buffer. Take samples from this solution and adjust volume with the same
buffer to obtain at least five standard solutions with protein concentrations between 0.1 mg/mL and
1 mg/mL and uniformly distributed over the chosen range.
Blank solutions. Use the same buffer used to prepare the sample and standard solutions.
Acid Blue 90 reagent. Weigh 0.10 g of acid blue 90 and dissolve in 50 mL of ethyl alcohol. Add 100
mL of phosphoric acid, adjust to 1000 mL with distilled water and homogenize. Filter the solution
and store it at room temperature in an amber glass flask. A slow precipitation of the dye occurs during
storage. The precipitate is filtered before using the reagent.
Procedure. To 0.100 mL of each Standard Solution, Sample Solution and Blank Solution add 5 mL
of Acid Blue 90 reagent. Homogenize the mixture by rotation, avoiding the formation of foam that
can create reproducibility problems. Determine the absorbance (5.2.14) of the Standard Solutions and
the Sample Solution at 595 nm using the Blank Solution for zero adjustment. The use of quartz (silica)
cuvettes is avoided since the dye binds to this material.
Calculations The relation between absorbance and protein content is not linear. However, if the
concentration range covered by the calibration curve is sufficiently narrow, the curve obtained will
be substantially linear. Plot the absorbance of Standard solutions according to the protein content of
these solutions and determine the calibration curve by linear regression analysis. From the calibration
curve and the absorbance of the Sample solution, determine the protein content of the Sample solution.
METHOD 4
This method, also known as the bicinchoninic acid (BCA) method, was developed based on the
property that proteins have to reduce cupric ion (Cu2+) to cuprous ion (Cu+). The bicinchoninic acid
reagent serves to detect cuprous ions. There are few interfering substances. If there are interfering
substances, it is possible to minimize their effects by dilution, as long as the protein content to be
dosed remains high enough to allow for an accurate determination. The protein precipitation method
described in Method 2 can be used to eliminate interfering substances. The intensity of the color
obtained by the reaction with the reagent may vary from one type of protein to another and, therefore,
the protein to be dosed and the reference protein are the same.
Use distilled water to prepare buffers and reagents to be used in this method.
Sample solution. Weigh an appropriate amount of the sample and dissolve in the indicated buffer so
as to obtain a concentration within the concentration range of the Standard Solutions.
Standard solutions. Weigh the reference substance corresponding to the protein to be dosed and
dissolve in the indicated buffer. Take samples from this solution and adjust to volume with the same
buffer to obtain minimum five standard solutions with concentrations between 10 μg/mL and
1200 μg/mL and evenly distributed over the chosen range.
Blank solutions. Use the same buffer that was used to prepare the Sample Solution and Standard
Solutions.
Procedure. Homogenize 0.1 mL of each Standard Solution, Sample Solution and Blank Solution with
2 mL of Copper-BCA Reagent. Incubate solutions at 37°C for 30 minutes. Allow to cool to room
temperature Within exactly 60 minutes following the incubation period, determine the absorbance
(5.2.14)) at 562 nm of the Standard Solutions and the Sample Solution in quartz cuvettes using the
Blank Solution for zero adjustment. When the temperature of the solutions returns to room
temperature, the color intensity continues to progressively increase.
Calculations The relation between absorbance and protein content is not linear. However, if the
concentration range covered by the calibration curve is sufficiently narrow, the curve obtained will
be substantially linear. Plot the absorbance of the standard solutions against the protein content of
these solutions and determine the calibration curve by linear regression analysis. From the calibration
curve and the absorbance of the sample solution determine the protein content of the sample solution.
METHOD 5
This method is also known as the biuret method, based on the property that proteins have to interact
with the cupric ion (Cu2+), in an alkaline medium, providing a reaction product that presents
absorbance at 545 nm. The use of this method makes it possible to obtain a minimum deviation
between equivalent IgG and albumin samples. On the contrary, simultaneous addition of sodium
hydroxide and biuret reagent (as a mixture), insufficient homogenization after addition of sodium
hydroxide or a very long time lag between addition of sodium hydroxide and sodium hydroxide
reagent. biuret leads to obtaining a higher response with IgG samples than with albumin samples.
Treatment with trichloroacetic acid used to reduce interferences can also make it possible to quantify
the protein when its concentration in the sample is inferior to 0.5 mg/mL.
Use distilled water to prepare buffers and reagents to be used in this method.
Sample solution. Weigh an appropriate amount of the sample and dissolve in 0.9% (w/v) sodium
chloride solution so as to obtain a concentration within the concentration range of standard solutions.
Standard solutions. Weigh the reference substance corresponding to the protein to be measured and
dissolve in 0.9% sodium chloride solution (w/v). Take samples of this solution and complete with
0.9% sodium chloride solution (w/v) to obtain at least three standard solutions with concentrations
between 0.5 mg/mL and 10 mg/mL and, uniformly, distributed into the chosen range.
Biuret reagent. Weigh 3.46 g of copper sulfate and dissolve in 10 mL of hot distilled water. Allow to
cool (solution A). Weigh 34.6 g of sodium citrate and 20 g of anhydrous sodium carbonate and
dissolve in 80 mL of hot distilled water and allow to cool (solution B). Homogenize solutions A and
B and adjust to 200 mL with distilled water. This reagent is used within 6 months upon preparation;
not used if turbidity or precipitate is produced.
Procedure. To one volume of Sample Solution add an equal volume of 6% sodium hydroxide solution
(w/v) and homogenize. Immediately add 0.4 volume (calculated in relation to the sample solution) of
Biuret reagent and homogenize quickly. Keep the samples for at least 15 minutes at a temperature
between 15 °C and 25 °C. Within 90 minutes of reagent addition, determine the absorbance (5.2.14),
at a maximum of 545 nm, of the Standard Solutions and the Sample Solution, using the Blank Solution
as compensation liquid. If turbidity or precipitates appear in the solutions, they are not used for
calculating the protein content.
Calculations The relation between absorbance and protein content is substantially linear over the
range of concentrations indicated for Standard solutions. Plot the absorbance of Standard solutions
according to the protein content of these solutions and determine the calibration curve by linear
regression analysis. Calculate the correlation coefficient for the calibration curve. The system satisfies
if it obtains a straight line whose correlation coefficient is not less than 0.99. From the calibration
curve and the absorbance of the Sample solution, determine the protein content of the Sample solution.
METHOD 6
This fluorimetric method was designed based on a derivation of the protein by o-phthalaldehyde
which reacts with the protein primary amines, that is, the N-terminal amino acid and the α-amine
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.1-00
function of the lysine residues. Assay sensitivity can be improved by pre-hydrolysis of the protein,
prior to adding o-phthalaldehyde. Hydrolysis frees the α-amine function from the constituent amino
acids of the protein and which enables it to react with the phthalaldehyde reagent. This method is
applicable to small amounts of protein.
The primary amines contained in, for example, tromethamine buffers and amino acid buffers react
with phthalaldehyde and are therefore to be avoided or eliminated. Ammonia in high
concentration also reacts with phthalaldehyde. The fluorescence resulting from the amine
phthalaldehyde reaction may be unstable. Using automated processes to standardize the method can
improve its accuracy and feasibility.
Use distilled water for the preparation of all buffers and reagents to be used in this method.
Sample solution. Weigh an appropriate amount of the sample and dissolve in 0.9% (w/v) sodium
chloride solution to obtain a concentration within the concentration range of Standard Solutions.
Adjust the pH of the solution to 8 –10.5 before adding the Phthalaldehyde Reagent.
Standard solutions. Weigh the reference substance corresponding to the protein to be measured and
dissolve in 0.9% sodium chloride solution (w/v). Take samples of the solution and complete the
volume with a 0.9% (w/v) sodium chloride solution to obtain at least five standard solutions with
concentrations between 10 μg/mL and 200 μg/mL and uniformly distributed over the chosen range.
Adjust pH of solutions to 8-10.5 before adding Phthalaldehyde Reagent.
Borate buffer. Weigh 61.83 g of boric acid, dissolve in distilled water and adjust pH to 10.4 with
potassium hydroxide solution. Adjust to 1000 mL with distilled water and homogenize.
Phtalaldehyde stock solution. Weigh 1.20 g of phthalaldehyde and dissolve in 1.5 mL of methyl
alcohol, add 100 mL of Borate buffer and homogenize. Add 0.6 mL of 30% (w/v) Macrogol 23 lauric
ether solution and homogenize. Store the solution at room temperature and use within three weeks of
preparation.
Method. Homogenize 10 μL of the Sample Solution and each of the Standard Solutions with 0.1 mL
of Phtalaldehyde Reagent and allow to stand at room temperature for 15 minutes. Add 3 mL of 0.5
M sodium hydroxide and homogenize. Determine the fluorescence intensity (5.2.15) of the Standard
Solution and Sample Solution samples at the excitation wavelength of 340 nm and the emission
wavelength of 440 nm to 455 nm. Determine the fluorescence intensity of a sample once as irradiation
causes a decrease in fluorescence intensity.
Calculations The relation between fluorescence intensity and protein content is linear. Plot the
fluorescence intensities obtained with the Standard Solutions according to the protein content of these
solutions and determine the calibration curve by linear regression analysis. From the calibration curve
and the fluorescence intensity of the Sample Solution, determine the protein content of the Sample
Solution.
METHOD 7
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.1-00
This method was developed based on the quantification of proteins by nitrogen assay. The presence
of other nitrogenous substances in the sample may affect the result of the protein assay. The
techniques used to measure nitrogen lead to the destruction of the sample during the analysis, but are
not limited to the determination of proteins in an aqueous medium.
Method A. Proceed as indicated for the measurement of nitrogen after mineralization by sulfuric acid
(5.3.3.2) or use instruments available on the market adapted to the nitrogen assay by the Kjeldahl
method.
Method B. There are devices on the market adapted for the nitrogen assay. Most of them use pyrolysis
(combustion of the sample in the presence of oxygen at temperatures close to 1000°C), which causes
the formation of nitrogen monoxide (NO) and other oxides to form NO x from the nitrogen existing
in the sample. Certain instruments convert these nitrogen oxides into nitrogen gas which is quantified
by thermal conductimetry. Others mix nitrogen monoxide (NO) with ozone (O 3) to produce nitrogen
dioxide in the excited state (NO 2) which emits light radiation when it decreases and is quantified by
chemiluminescence. A reference product, relatively pure, and similar in composition to the protein to
be dosed is used to optimize the injection and pyrolysis parameters and to assess the analysis
reproducibility.
Calculations The protein content is calculated by dividing the nitrogen content of the sample by the
(known) nitrogen content of the protein which can be determined either from the chemical structure
of the protein or by comparison with an appropriate reference substance.
Use a mixture of D-positive erythrocytes, less than seven days old and stored under appropriate
conditions, obtained from at least four donors from the OR1R1group. To an appropriate volume of
erythrocytes, previously washed three times with 0.9% (w/v) sodium chloride solution, add an equal
volume of bromelain RS, allow to stand at 37°C for 10 minutes. Centrifuge, discard the supernatant
liquid and wash the erythrocytes three times with 0.9% sodium chloride solution (w/v). Suspend 20
volumes of erythrocytes in a mixture of 15 volumes of inert serum, 20 volumes of 30% (w/v) bovine
albumin solution, and 45 volumes of 0.9% (w/v) sodium chloride solution. Place the suspension in
ice water under continuous shaking.
With a calibrated automatic dilution device prepare sample and standard solution dilutions in a 0.5%
(w/v) bovine albumin and 0.9% (w/v) sodium chloride solution.
Use an appropriate device for continuous automatic analysis; keep the temperature in the kits at 15°C
with the exception of the incubation spirals. Aspirate the erythrocyte suspension at a flow rate of 0.1
mL per minute and a 0.3% (w/v) methylcellulose 450 solution at a flow rate of 0.05 mL per minute
into the device inlet kits.
Introduce the sample and standard solution dilutions at a rate of 0.1 mL per minute for two minutes
and then the diluent at a rate of 0.1 mL per minute for four minutes before introducing the next
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.1-00
dilution. Introduce air at a rate of 0.6 mL per minute. Incubate at 37°C for 18 minutes and then
disperse the spirals by introducing, at a rate of 1.6 mL per minute, a 0.9% (w/v) sodium chloride
solution containing an appropriate wetting agent (e.g. polysorbate 20 at a final concentration of 0.2
g/L) to avoid changing the continuity of the bubbles. Allow the agglutinates to settle and decant twice,
the first time at 0.4 mL per minute and the second time at 0.6 mL per minute. Lyse the residue of
unagglutinated erythrocytes using a solution of 10 to 0.5% (w/v) of octoxynol, 0.02% (w/v) potassium
ferricyanide, 0% sodium bicarbonate .1% (w/v) and potassium cyanide at 0.005% (w/v), with a flow
rate of 2.5 mL per minute. A 10-minute delay coil is introduced to allow for the hemoglobin
transformation.
Carry out continuous registration (5.2.14) of the hemolysate absorbance at a wavelength from 540 to
550 nm.
Determine antibody concentrations for which there is a linear relationship between concentration and
change in absorbance (ΔA). Based on the results, plot a calibration curve and use the linear portion
of the curve to determine sample activity. Calculate sample activity in international units per milliliter
using the formula:
𝑎×𝑑
𝐷
where
a = activity of the reference preparation in international units per milliliter at a dilution of 1 in D;
d = sample dilution factor that corresponds to a given value of ΔA;
D = dilution factor of the standard solution corresponding to the same ΔA value.
Stabilized human blood. Carry out a phlebotomy to collect group O human blood in an ACD-type
conservative anticoagulant solution. Store stabilized human blood at 4°C for not more than three
weeks.
Phosphate buffered saline solution pH 7.2. Weigh 1.022 g of anhydrous sodium phosphate dibasic,
0.336 g of monobasic sodium phosphate and 8.766 g of sodium chloride, dissolve in 800 mL of water
and adjust to 1000 mL with the same diluent.
Magnesium and calcium stock solution. Weigh 1.103 g of calcium chloride and 5.083 g of magnesium
chloride, dissolve in water and adjust to 25 mL with the same diluent.
Barbital buffer stock solution. Weigh 207.5 g of sodium chloride and 25.48 g of sodium barbital,
dissolve in 4000 mL of water and adjust to pH 7.3 with M hydrochloric acid. Add 12.5 mL of the
Magnesium and calcium stock solution and adjust to 5000 mL with water. Filter through membrane
(0.22 μm) and store at 4 °C in a glass container.
Tannic acid solution. Weigh 10mg of tannic acid and dissolve in 100 mL of pH 7.2 Phosphate
Buffered Saline Solution. Prepare immediately before use.
Guinea pig complement. Homogenize the sera obtained from at least 10 guinea pigs. Separate serum
from clotted blood by centrifugation at a temperature of approximately 4°C.
Store the serum, in small portions, at a temperature below -70 °C. Immediately before starting
hemolysis by the action of complement, dilute to 125 –200 CH50 per milliliter with Barbital Albumin
Buffer and, during the assay, keep the diluted solution in ice bath.
Rubella antigen. Rubella antigen suitable for hemagglutination inhibition titrations. Titration > 256
HA units.
PROCEDURE
Homogenize 900 μL of Barbital Albumin Buffer with 100 μL of vi,which is thus reduced to the
residual volume, and determine the initial absorbance at 541 nm (A). Dilute v r by a factor equal to A
using Barbital Albumin Buffer. This gives the final adjusted volume vf =vr x A of sensitized human
erythrocytes and a value for A of 1.0 ± 0.1 in the case of a 1/10 dilution. Antibody binding to
erythrocytes with tannic acid and covered with antigen. Prepare, in duplicate, and successively, the
following solutions using for each solution, separately, a semi-micro cuvette (for example, disposable
plates) or a test tube for each solution:
(1) Sample solutions. If necessary, adjust the sample to pH 7 by adding, for example, M sodium
hydroxide. Use sample volumes containing, respectively, 30 mg and 40mg of immunoglobulin and
complete 900 µL with Barbital Albumin Buffer.
(2) Standard solution. Prepare the solution as described for Sample Solution from a human
immunoglobulin reference standard.
(3) Complement Evidence. 900µL of Barbital Albumin Buffer. Add 100µL of sensitized human
erythrocytes to each cuvette/test tube and homogenize carefully. Allow to stand for 15 minutes, add
1000 μL of Barbital Albumin Buffer, collect the erythrocytes by centrifugation (1000 g for 10
minutes) from the cuvette/test tube and remove 1900 μL of the supernatant. Replace this volume with
1900 μL of Barbital Albumin Buffer and repeat the washing procedure leaving a final volume of
200 μL. Samples can be stored in closed cuvettes/test tubes at 4°C for 24 hours.
Complement activation hemolysis. To determine hemolysis, add 600 μL of Barbital Albumin Buffer
heated to 37 C to the sample, carefully suspend the erythrocytes by pipetting them repeatedly (at least
five times) and place the cuvette in the sample holder of a spectrophotometer with thermostat. After
two minutes, add 200 μL of Guinea Pig Complement diluted to 125 – 200 CH 50/mL, carefully
homogenize the mixture, pipetting the mixture twice and immediately after the second pipetting start
recording the absorbance at 541 nm as a function of time, using Barbital-albumin buffer as
compensation liquid. Stop recording if the absorbance versus time curve clearly exceeds the inflection
point.
Assay. Determine the slope (S) of the hemolysis curve at the approximate point of inflection by
segmenting the curve in the region of greatest slope by appropriate time ranges (for example, Δt =
one minute) and calculating S, expressed in ΔA per minute between the points of adjacent
intersection. The highest value of S corresponds to (Sexp). Also determine the absorbance at the
beginning of the curve (As) by extrapolating the curve, which is almost always linear and parallel to
the time axis in the first minutes of the registration. Correct S exp according to the formula:
𝑆𝑒𝑥𝑝
𝑆′ =
𝐴𝑠
For each preparation, calculate the arithmetic mean of the S’ values. Calculate the function index Fc
(IFc ) from the formula:
𝑆 ′ − 𝑆′
𝐼𝐹𝑐
𝑆′𝑠 − 𝑆′𝑐
where
S’ = arithmetic mean of the slope corrected for the sample;
S s’= arithmetic mean of the slope corrected for the standard;
S s= arithmetic mean of the slope corrected for the complement evidence;
Calculate the index of the function F c for the sample. The value is not inferior to that indicated by
the standard manufacturer.
The serological classification of the HLA system can be determined using the complement-dependent
microlymphocytotoxicity assay, also known as the Terasaki and McClelland method modified by
Bodmer, which is the most commonly used method. In this test, specific mono or polyclonal sera
against HLA system antigens present in lymphocytes are used. Viable cells are extracted from
peripheral blood, lymph nodes, spleen and others.
With this serological assay it is possible to measure cell mortality through complement activation
(rabbit) in the presence of specific antigen-antibody combinations. The antigen-antibody complement
reaction is measured by viewing the test under a microscope at 100 to 150 times magnification, with
phase contrast illumination and a vital stain, using diluted eosin Y, propidium iodide or trypan blue
in 1% aqueous solution (w/v). Dead cells (which have the antigen detected by the specific antiserum)
will absorb the contrast and show an appropriate color change. Negative cells (those that do not have
the antigen detected by the specific antiserum) remain viable and exclude the contrast.
In these tests, plates with a 72-well "V" bottom and with specific anti-HLA human serum of murine
origin or ready-to-use HLA classification trays, also known as Terasaki plates, are used, provided
they are regulated by the competent authority. In this type of ready-to-use plate, the operationally
monospecific and polyspecific or multispecific antisera for HLA antigens are already fixed. Positive
and negative controls must always be used.
Ready-to-use plates or trays are typically prepared with 1 μL of antisera in each well, 0.1% sodium
azide as preservative and phenol red as pH indicator, and are coated with 4 μL to 5 μL of mineral oil
to avoid dryness and prolong the time of use.
Sample preparation (lymphocyte suspension) using the density gradient separation method: collect
10 mL of whole blood in a vacuum test tube with heparinized solution, ACD or sodium citrate as
anticoagulant. Gently homogenize by inversion a few times and centrifuge the blood for 10 minutes
at 700 to 900 g to obtain a buffy coat.
Note: centrifugation can be replaced by the use of 2 mL of a 5% dextran solution, which must be
added to the whole blood sample, using an anticoagulant. Allow the mixture to stand for 15 minutes
at a temperature of 37 ºC. The use of this solution allows the sedimentation of red blood cells.
Carefully remove the buffy coat, using a Pasteur pipette, the volume of which should be 2 mL, transfer
to a clean 17 x 100 mm test tube containing 5 mL of phosphate-buffered saline solution (PBS) and
Viability test: add one drop of 0.4% trypan blue dye in aqueous solution and one drop of cell
suspension or 19 drops of 0.4% trypan blue dye in PBS and one drop of cell suspension in a clean
test tube and then mix well. Incubate the mixture at room temperature for 15 minutes. Examine cell
viability on a cell counter. Viable cells have intact cell membranes and appear smooth; are able to
exclude trypan blue and consequently will not be stained. Non-viable cells do not have intact cell
membranes and do not appear smooth; are unable to exclude trypan blue and consequently will be
stained. If there are non-viable cells, the sample should not be used.
B and T lymphocytes are easily separated using the nylon wool column method. B cells and
macrophages have the attribute of adhering to nylon wool, whereas T cells do not.
Using magnetic particles, it is possible to separate T lymphocytes from B lymphocytes. The immunomagnetic
spheres are made up of superparamagnetic particles with monoclonal antibodies anti-CD2 for T lymphocytes
and anti-CD19 for B lymphocytes, coupled to their respective surfaces. The spheres can be collected using a
magnetic field, which after removal does not leave any residual magnetism in the spheres.
PROCEDURE
Prepare a lymphocyte suspension with a minimum viability of 80%, without excessive contamination
by non-lymphoid cells. Using ready-to-use HLA grading trays, thaw and allow trays to reach room
temperature. Using blank plates, add 1 µL of the corresponding antiserum to each properly labeled
well. Add 1 µL of lymphocyte suspension to be tested (approximately 3000 lymphocytes), using a 50
µL automatic pipettor, to the top of each test well, taking care not to touch the antisera. Homogenize
and examine each well to ensure homogeneity of the lymphocyte suspension with the antiserum.
Incubate trays at 22°C ± 3°C for 30 minutes. Add 5 µL of rabbit complement to the test wells using
a 250 µL automatic pipettor, taking care not to touch the pipette tip in the antisera/lymphocyte
mixture. Incubate trays at 22°C ± 3°C for 60 minutes. Add 2 µL of 5% eosin solution in pre-filtered
aqueous solution to each test well and incubate at 22°C ± 3°C for three to five minutes. Take care not
to touch the pipette tip in the antiserum/lymphocyte mixture. Add 5 µL of 12-37% neutralized
formalin with a pH of 7.0 ± 0.2 filtered to each test well. Take care not to touch the pipette tip in the
antiserum/lymphocyte mixture. Read the test under a microscope at 100 to 150 times magnification
under phase contrast illumination.
Prepare a lymphocyte suspension with a minimum viability of 80%, without excessive contamination
by non-lymphoid cells. Using ready-to-use HLA grading trays, thaw and allow trays to reach room
temperature. Using blank plates, add 1 µL of the corresponding antiserum to each properly labeled
well. Add 1 µL of lymphocyte suspension to be tested (approximately 3000 lymphocytes), using a 50
µL automatic pipettor, to the top of each test well, taking care not to touch the antisera.
Homogenize and examine each well to ensure homogeneity of the lymphocyte suspension with the
antiserum. Incubate trays at 22°C ± 3°C for 30 minutes for HLA Class I (A, B and C) and 45 minutes
for HLA Class II (DR and DQ). Add 5 µL of rabbit complement to the test wells using a 250 µL
automatic pipettor, taking care not to touch the pipette tip in the antisera/lymphocyte mixture.
Incubate trays at 22°C ± 3°C for 50 minutes for HLA Class I (A, B and C) and 60 minutes for HLA
Class II (DR and DQ). Add 5 µL of 1% propidium iodide in aqueous solution to each of the test wells,
taking care not to touch the pipette tip in the antisera/lymphocyte mixture. Cover the plates to avoid
dehydration and allow to stand for 15 minutes for the lymphocytes to sediment. Read the test under
a microscope at 100 to 150 times magnification under phase contrast illumination. Fluorescence-
labeled viable cells are shown in green and non-viable cells are shown in red. The test can also be
read using direct fluorescence microscopy, where viable cells will be fluorescent.
Results: non-viable cells (those that have the antigen) absorb propidium iodide, appear enlarged and
darkened and demonstrate clear nuclear details. Viable cells (those that do not have the antigen)
exclude propidium iodide and appear slightly brighter and smaller compared to non-viable cells. After
correction for the percentage of non-viable cells in negative control cells, the test is classified
according to Table 2.
5.5.2.1 PYROGENS
The pyrogen test is based on measuring the increase in body temperature in rabbits, after intravenous
injection of the sterile solution under analysis. For products well tolerated by animals, use a dose that
does not exceed 10 mL/kg, injected in a time not exceeding 10 minutes. For products that require
preliminary preparation or special administration conditions, follow the recommendations established
in the monograph.
General conditions
Use rabbits of same sex, healthy adults, preferably of the same breed, weighing not less than 1.5 kg.
After selection, keep the animals in individual cages in a room with uniform temperature between 20
and 23 ºC, free from disturbances that may stress them. The selected temperature can vary up to ±
3 °C.
Carry out conditioning to determine the temperature of the animals, minimum once, up to seven days
before starting the test. The animals must be conditioned according to the same test procedure only
without product inoculation. Animals that present a temperature rise equal to or greater than 0.5 ºC,
in relation to the initial temperature, should not be used in the test.
When carrying out the test, use only animals with a temperature equal to or lower than 39.8 ºC and
that do not present, from one to the other, a variation greater than 1.0 ºC.
Temperature record
Use clinical thermometer calibrated with an accuracy of ±0.1 °C or any other calibrated temperature
recording device of equal sensitivity. Introduce the thermometer into the animal's rectum at a depth
of approximately 6 centimeters. If a recording device is used, which must remain in the rectum during
the test period, contain the rabbits so that they are in a natural standing posture. When using a clinical
thermometer, allow the necessary time (previously determined) to elapse to reach the maximum
temperature, before proceeding with the reading.
Material
Sterile and non-pyrogenic syringes, needles and glassware. Diluents and extracting or washing
solutions must also be sterile and non-pyrogenic.
Procedure
Perform the test in an area specially designed for testing, under controlled environmental conditions,
free from disturbances that may stress the rabbits. In the preceding two hours and during the test,
withhold food supply. Access to water is allowed but may be restricted during testing.
Not more than 40 minutes before injecting the dose of the product to be tested, record the temperature
of each animal through two readings taken with a 30 minute-range. The average of the two readings
will be taken as the control temperature required to assess any individual temperature rise subsequent
to sample injection.
Prepare the product to be tested as specified in the monograph and heat at (37 ± 2) °C. For the pyrogen
test of materials for hospital use, wash, with sterile saline solution, the surfaces of the material that
come into contact with the product, injection site or the patient's internal tissue. Carry out the
procedures ensuring that the solution is not contaminated.
Inject through the marginal ear vein of three rabbits not less than 0.5 mL or more than 10 mL of the
solution per kg of body weight or the amount indicated in the monograph. The injection should not
last longer than 10 minutes, unless a different time is specified in the monograph. Record each
animal's temperature at 30-minute ranges for three hours after injection.
Interpretation
Do not consider the decreases in temperature shown by the animals during the test. The temperature
rise is verified by the difference between the highest temperature presented by the rabbit during the
test and its control temperature.
If none of the three rabbits present an individual increase in temperature equal to or greater than
0.5 ºC, in relation to their respective control temperatures, the product complies with the requirements
of the pyrogen test.
If any rabbit shows an increase in temperature equal to or greater than 0.5°C, repeat the test using
another five animals.
The product under examination meets the requirements for the absence of pyrogens if at most three
of the eight rabbits show individual increases in temperature equal to or greater than 0.5 ºC, and if
the sum of the individual increases of all rabbits does not exceed 3.3 ºC .
The bacterial endotoxin test is used to detect or quantify gram negative bacterial endotoxins present
in specimens for which the test is recommended. The aqueous extract of circulating amoebocytes
from Limulus polyphemus or Tachypleus tridentatus prepared and characterized as LAL reagent is
used.
There are two methods with different sensitivity for this test:
Any of these procedures can be performed, unless otherwise indicated in the monograph.
In the gel-clot method, the determination of the reaction endpoint is carried out from dilutions of the
substance under test in direct comparison with parallel dilutions of the standard endotoxin. Levels of
endotoxins are expressed in defined endotoxin units (EU). Note: 1 EU is equal to 1 IU (international
unit).
LAL reagent (Limulus Amebocyte Lysate sp.) is prepared for turbidimetric or colorimetric readings
and these procedures can be used if they meet the methods requirements. For its calibration, it is
necessary to plot a standard curve, obtaining its linear regression, which determines, by interpolation,
the endotoxin concentration of the substance under test.
The procedure includes incubation of standard endotoxin to obtain a calibration curve and control
solutions with LAL reagent, for a predetermined time and spectrophotometric reading at the
appropriate wavelength.
In the turbidimetric method procedure, the reading is taken immediately after the final incubation
period whereas for the colorimetric procedure, the enzymatic reaction is interrupted at the end of the
time predetermined by the reagent addition, before the readings. For kinetic turbidimetric and
colorimetric procedures the absorbance values measured during the reaction period and velocity
values are determined for those readings.
All glassware must be depyrogenized in an oven under a validated process. Use a minimum time and
temperature of 250 ºC for 30 minutes. If using plastic disposables, such as tips and pipettes, only use
the certificates that indicate they are free of endotoxins so as not to interfere with the test.
The reference endotoxin standard has a defined potency of 10 000 EU (endotoxin units) per flask.
Reconstitute the vial with 5 mL of LAL reagent grade water (pyrogen-free) and vortex agitate
intermittently for 30 minutes. Use this concentrated solution (stored in a refrigerator for not more
than 14 days) to make serial dilutions. Shake vigorously before use for at least three minutes and
proceed with serial dilutions, shaking at least 30 seconds before the next dilutions. After use, discard
dilutions due to activity loss by adsorption. For the preparation of the endotoxin standard, follow the
supplier's guidelines, certified in the endotoxin report.
Test Preparation
Use LAL reagent with confirmed stated sensitivity. The validity of test results for bacterial endotoxins
requires demonstration that the samples, wash solutions or extracts under test do not inhibit or
potentiate the reaction, nor do they interfere with the test. Validation is performed by means of the
inhibition or potentiation test described for each of the methods indicated. Appropriate negative
controls are included. The validation must be repeated if there is a change in the LAL reagent origin,
the production method or the formulation of the substance under test.
Sample solution: prepare the sample solution by diluting in LAL reagent grade water. If necessary,
adjust the pH of the sample solution so that the LAL reagent mixture with sample has a pH between
6 and 8. The pH can be adjusted using a suitable buffer recommended by the supplier. Acids and
bases can be prepared with LAL reagent grade water and validated to be free of endotoxins and
interfering factors.
The maximum valid dilution is the maximum allowable dilution of the sample under analysis where
the endotoxin limit can be determined. It applies for injections or solutions for parenteral
administration in reconstituted or diluted form for administration, amount of drug by weight, if the
volume of the dosage form is variable.
𝑙𝑖𝑚𝑖𝑡𝑒 𝑑𝑒 𝑒𝑛𝑑𝑜𝑡𝑜𝑥𝑖𝑛𝑎
𝑀𝐷𝑉 =
𝜆
When the endotoxin limit of the drug specified in the monograph is in weight (EU/mg) or in active
drug unit (EU/units), the MVD is calculated by the following formula:
where
λ = labeled sensitivity of the LAL reagent.
The MVD obtained is the limiting dilution factor for the test to be validated.
The formula for setting endotoxin limit for parenteral drugs is:
𝐾
𝐿𝐸 =
𝑀
where
EL = endotoxin limit;
K = human limit dose of endotoxin per kilogram of body weight;
M = maximum dose of product per kg of weight in a period of one hour.
The endotoxin limit is specified in the parenteral drugs individual monographs in EU/mL, EU/mg or
EU/unit of biological activity.
GEL-CLOT METHOD
The gel-clot method allows the detection and quantification of endotoxins based on the gelation
reaction of the LAL reagent. Labeled LAL sensitivity is the concentration of endotoxin required to
cause a gelation of the LAL reagent.
To ensure the accuracy and validity of the assay, tests are required to confirm labeled LAL sensitivity
as well as tests to check interfering factors, as described in sample preparation for the test.
Confirm the declared LAL sensitivity using not less than one vial of LAL reagent and prepare a series
of endotoxin dilutions using the reference standard endotoxin (RSE) or the control standard endotoxin
(CSE), with geometric ratio equal to 2 to obtain the concentrations of 0.25 λ, 0.5 λ, λ and 2 λs, where
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.2-01
λ is LAL declared sensitivity in EU/mL. Carry out the test with all four standard endotoxin
concentrations in quadruplicate and include negative controls. The geometric mean of the endpoint
concentration, calculated and interpreted below, must be greater than or equal to 0.5 λ and lower than
or equal to 2 λ. Confirmation of LAL sensitivity must be performed for each new LAL batch.
Results and interpretation. The gelling endpoint is the last test in the descending series of standard
endotoxin concentration that formed gel. Calculate the logarithmic geometric mean of the gelation
endpoints and the mean antilog by the formula:
𝐸𝑒
geometric mean of the endpoint concentration = 𝑎𝑛𝑡𝑖𝑙𝑜𝑔 ( )
𝑓
where
Ee = sum of endpoint concentrations log of the dilution series used;
f = number of replicates.
The LAL reagent sensitivity in EU/mL is calculated by the formula above and must be not less than
0.5 λ and not more than 2 λ.
Carry out the test on sample aliquots in which there is no detectable endotoxin and on dilutions that
do not exceed MVD (maximum valid dilution). Perform the test, as in the test procedure, on the
sample without added endotoxin (solution A) and on the sample with added endotoxin (solution B),
at concentrations of ¼ λ, ½ λ, 1 λ and 2 λ, in quadruplicates, and also testing in parallel the same
concentrations of endotoxin in water (solution C) and negative control in LAL reagent grade water
(solution D) in duplicate.
Calculate the geometric mean endotoxin concentration of the sample gelling endpoint as described in
the test procedure above (test for confirmation of LAL sensitivity).
The test is valid for the sample under analysis if the geometric mean of this concentration is greater
than or equal to 0.5 λ and less than or equal to 2 λ. If the result obtained in the samples in which
endotoxin was added is out of the specified limit, the endotoxin inhibition or potentiation test must
be repeated after neutralization, inactivation or removal of interfering substances or after dilution of
the sample by a factor that does not exceed the MVD. Repeat the test at a higher dilution not exceeding
the MDV or use a higher LAL sensitivity so that interference can be eliminated in the analyzed
sample. Interferences can be eliminated by suitable treatment such as filtration, neutralization,
dialysis or heating.
This test is used when the monograph contains endotoxin limit requirements.
Procedure. Carry out the tests in duplicate with solutions A, B, C and D as follows. Prepare diluted
sample solution without adding endotoxin (solution A); with addition of endotoxin (product positive
control) at 2 λ (solution B); LAL reagent grade water with endotoxin added at 2 λ (solution C) and
LAL reagent grade water without added endotoxin (solution D – negative control). Dilution of
solution A and B must not exceed MVD.
Interpretation The test will only be valid if the replicas of positive controls from solutions B and C
form a gel and the replicas of negative controls from solutions A and D do not form a gel. Contrary
results will not be valid and must be repeated.
Homogenize one volume (e.g. 100 μL) of LAL with an equal volume of the above solutions, sample,
standards and negative control of the test in 10 x 75 mm test tubes, in duplicate. Incubate the tubes
for one hour at (37 ± 1) °C, avoiding vibrations. After this period, remove the tubes one by one,
turning 180 degrees and checking the integrity of the gel; if the gel remains firm after inverting the
tubes, consider the result as positive, and if there is no gel formation or it is not firm, consider it as
negative.
The test will only be valid if the following conditions are met:
- If both replicas of the negative control (D) show negative reactions;
- If both replicas of the positive control of the product (B) show positive reactions;
- If the geometric mean of solution C is within the range of 0.5 λ to 2 λ.
To calculate the endotoxin concentration of solution A, calculate the endpoint concentration of each
replicate in the dilution series by multiplying each endpoint dilution factor by the labeled sensitivity
of the LAL reagent (λ). The endotoxin concentration in the test solution is the geometric mean of the
concentration of the replicas limit.
If the test is carried out on the diluted sample, determine the endotoxin concentration in the original
solution by multiplying the result by the sample dilution factor. If none of the test sample dilutions
are positive, express the endotoxin concentration result as lower than the LAL sensitivity (λ) or lower
than the LAL sensitivity multiplied by the lowest sample dilution factor. If all sample dilutions show
positive reactions, the endotoxin concentration is expressed as equal to or greater than λ multiplied
by the highest sample dilution factor.
The sample meets the test requirements if the endotoxin concentration is lower than the individual
limit specified in the monograph.
PHOTOMETRIC METHODS
TURBIDIMETRIC METHOD
This method is based on measuring turbidity increase and, depending on the principle employed, it
can be classified into two types:
A. Turbidimetric limit: based on the relation between the endotoxin concentration and the reaction
turbidity (absorbance or transmission).
B. Kinetic turbidimetric: method based on the reaction time (onset time) necessary for the reaction
mixture to reach a predetermined absorbance or on the turbidity development rate.
CHROMOGENIC METHOD
Blank preparation:
To ensure the accuracy and validity of turbidimetric and chromogenic tests, preparatory tests are
performed to ensure that the criteria for the standard curve are satisfactory and that the sample under
test does not interfere with the test. Method validation is required when any change in experimental
conditions is made and may interfere with the test.
Prepare a standard curve using three endotoxin concentrations, using a prepared endotoxin standard
solution, and perform the test at least in triplicate of each concentration, as recommended by the LAL
supplier (volume ratio, incubation time, temperature and pH, etc.)
If a range greater than 2 logs is desired, a standard concentration should be added to increase the
range of the standard curve. The absolute value of linear correlation R must be greater than or equal
to 0.980 for the endotoxin concentration range indicated by the LAL supplier.
Prepare diluted sample solutions without exceeding the MDV (maximum valid dilution) without
endotoxin (solution A) and with added endotoxin (solution B) at a concentration equal to or close to
the midpoint of the standard curve. Prepare a series of positive control with endotoxin solutions
(seduction C) with three different concentrations and also the negative control with pyrogenic water
(solution D) and carry out the tests by adding LAL reagent, at least, in duplicate (follow the guidelines
of the reagent used with respect to sample and reagent volume, incubation time, etc.), the lowest point
of the curve is considered λ.
Calculate the mean recovery of endotoxin added to the sample by subtracting the endotoxin
concentration mean in the test solution (solution A), if any, from the mean of the solution whose
endotoxin was added (solution B).
The test solution is considered to be interference-free if the level of endotoxin concentration added to
the test solution (solution B) is in the range of 50% to 200% recovery, after subtraction of any
endotoxin detected in the solution without endotoxin addition.
When endotoxin recovery is within the specification range, interference factors should be removed
as described in the gel-clot method section.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.2-01
Procedure
Follow the procedures described above in the items: Test preparation and Testing for interference
factors.
Calculate the endotoxin concentration for each replicate of solution A using the standard curve
generated by the positive control series solution C.
The test is only valid if the three following requirements are met:
- The result obtained from solution D (negative control) does not exceed the limit of the blank value
required in the description of the lysate used;
- The result obtained with the positive control series, solution C, is in accordance with the validation
requirements defined in the standard curve criteria;
- The endotoxin recovery, calculated from the endotoxin found in solution B after subtracting the
endotoxin concentration found in solution A, is within the range of 50 to 200%.
The sample solution to be examined will comply with the test if the endotoxin concentration mean
found in the replicates (solution A), after correction for dilution and concentration, is lower than the
endotoxin limit of the product tested.
REAGENTS
Amoebocyte lysate
The amoebocyte lysate is a lyophilizate obtained from the amoebocyte lysate of a horseshoe-shaped
crustacean (Limulus polyphemus or Tachypleus tridentatus). This reagent refers only to the product
manufactured in accordance with the regulations of competent authority. The lysate also reacts with
some B-Glucans in addition to endotoxins. Lysate preparations that do not react with B-Glucans are
also available; they are prepared either by removing or inhibiting factor G, which reacts with glucans.
These preparations can be used for endotoxin testing in the presence of glucans.
Reagent Reconstitution
Dissolve the amoebocyte lysate (LAL) in reagent grade water for BET (bacterial endotoxin test) or
buffer, without agitation, and store in refrigerator or freezer according to supplier's recommendation.
Test water is water for injections or water produced by other procedures that demonstrate no reaction
with the lysate used at the reagent detection limit.
5.5.2.3 TOXICITY
The toxicity test detects unexpected and unacceptable biological reactivity of drugs and medications.
This in vivo test is recommended for evaluating the safety of biological products and biotechnology
derivatives.
GENERAL TEST
Choice of animals.
Use healthy mice, of either sex, of known strain, not previously used in biological tests. Keep them
under uniform diet, unrestricted water and at constant room temperature of (21 ± 3) ºC. On the test
day, select mice weighing between 17 g and 22 g.
Sample preparation
The sample must be prepared as specified in the respective monograph and administered immediately.
Procedure
Use sterile syringes, needles and glassware. Administer, in five mice, the volume of the sample
preparation indicated in the monograph, by one of the routes described below.
Intravenous – Inject the dose into the tail vein, maintaining a constant rate of 0.1 mL per second or
as indicated in the monograph.
Interpretation
Keep the animals under observation for 48 hours upon administration or for the time indicated in the
monograph. The sample meets the test if all animals survive and not more than one shows abnormal
symptoms within the established time range. If one or two animals die, or more than one show
abnormal symptoms or unexpected toxicity, repeat the test using another five or fifteen mice,
weighing between 19 g and 21 g. The sample meets the test requirements if the number of dead mice
does not exceed 10% of the total animals tested, including the original test, and no animals in the
second group show symptoms indicative of abnormal toxicity.
Choice of animals.
Use not less than five mice weighing between 17 g and 22 g and minimum two healthy guinea pigs
weighing between 250 g and 350 g.
Procedure
Weigh the animals and record in a proper form before injecting the sample. Unless otherwise specified
in the monograph, intraperitoneally inject each animal with the equivalent of one human dose of the
preparation, not exceeding 1.0 mL for mice and 5.0 mL for guinea pigs. The human dosage is defined
on the label of the preparation under test or on the accompanying package insert.
Interpretation
For a period of at least seven days, observe the animals for signs of illness, weight loss, abnormalities
or death. If, during the observation period, all animals survive, do not show responses that are not
specific or expected for the product, and do not undergo weight loss, the preparation complies with
the test. Otherwise, the test must be repeated for species for which the requirements have not been
met. The preparation meets the test if all animals in the second group meet the criteria specified for
the initial test.
If, after the second test, the preparation does not meet the requirements, but no deaths are observed
in a percentage equal to or greater than 50% of the total number of animals tested, a second retest can
be performed in the species in which requirements were not complied with. Use twice as many
animals as the initial test. If the animals meet the specified criteria for the initial test, the preparation
meets the test.
As a standard preparation, use epinephrine bitartrate. This preparation must be kept in opaque,
hermetic vials and dried on silica gel for 18 hours before use.
Standard dilution
Dilute the epinephrine standard reference solution in saline solution so that the administration of a
dose between 0.1 mL and 0.5 mL produces an increase of 20mm to 70mm of mercury in blood
pressure.
Method
Select rats, weighing between 275 g and 325 g, and anesthetize with an anesthetic that allows the
maintenance of constant blood pressure (free of effect on blood pressure). Immobilize the animal and
keep it warm to prevent loss of body heat. Surgically carry out tracheal intubation, if necessary, and
expose the femoral or jugular vein, preparing it for intravenous injections. Administer 200 units of
heparin per 100 g of body weight. Surgically expose the carotid and cannular artery, connecting it to
the manometer set for continuous recording of blood pressure.
Inject, intravenously, 0.1% (w/v) atropine sulfate solution at the rate of 1 mL per kilogram of body
weight. Consider the muscarinic receptor sufficiently blocked only if subsequent injections of the
recent 0.001% (w/v) acetylcholine chloride solution at a dose of 1 ml per kilogram of weight do not
produce a transient drop in blood pressure. If this mechanism is not sufficiently paralyzed, inject a
0.5 mL dose of atropine sulfate solution until complete paralysis.
Procedure
Select dose of standard dilution that produces an increase between 2.7 kPa and 9.3 kPa (20mm to
70mm mercury) in blood pressure. Inject the dosage at constant ranges of minimum five minutes to
allow the blood pressure to return to baseline. After each injection, immediately administer 0.2 mL
of saline solution to wash the cannula. Ensure response reproducibility by repeating the dose two or
more times. Administer a new dose of the standard dilution so as to obtain hypertensive responses
approximately 20% greater than the mean of the lower dose responses. Consider the animal apt for
the test if (1) the responses to the first selected dose are reproducible between 2.7 kPa and 9.3 kPa
(20mm to 70mm of mercury) and (2) significantly lower in relation to the response of higher dose.
Keeping the established time range constant, inject a series of five doses in which the selected dosage
of the standard dilution and the dosage of the same volume of the substance under test, diluted
conveniently, are alternated. After each of the five injections, measure the change in blood pressure.
Calculate the difference between each sample response and the response mean of the immediately
prior and subsequent standard dilution doses. The sample meets the test requirements if the average
of these differences means that the responses obtained with the sample solution are not higher than
those with the standard dilution. Results must match the pressor activity limit specified for that test
in the corresponding monograph.
5.5.2.5 HISTAMINE
Euthanize a guinea pig weighing between 250 g and 350 g, fasting for approximately 24 hours. Resect
approximately 10 cm of the ileum distal portion. Wash internally with nutrient solution. Select a
portion about two or three centimeters long and tie two thin threads at the ends. Make a small incision
in the central portion of the tissue. Transfer to an isolated organ bath, with a capacity of 10 mL to
20 mL, at a controlled temperature between 34 ºC and 36 ºC under an air stream or a mixture of 95%
oxygen and 5.0% CO2 . Attach one of the threads to the bottom of the tank and tie the other to the
lever designed to record muscle contractions in the kymograph or other suitable recording system.
Adjust the lever for recording ileum contractions with an amplification degree of the order of 20
times. Wash the preparation with the solution and allow to stand for 10 minutes.
Add known volumes – 0.2 mL to 0.5 mL of histamine reference standard solution (1 g/mL) – to obtain
an optimal response (higher dose). Wash the ileum three times with nutrient solution. Add successive
additions at regular ranges of approximately two minutes. Add new doses of histamine reference
standard solution – obtained by diluting the original solution to keep the dose volumes always the
same – establishing the dose responsible for the response whose intensity is half the highest dose
(lower dose).
Proceed with the test by adding sequences of three doses: lower reference standard dose, solution
dose of the substance under test and higher reference standard dose. Adjust the sample dilution so
that, in the event of ileum contraction, it is lower than that produced by the higher reference standard
dose. Establish the contraction reproducibility by serial repetitions of dose sequences.
Calculate the activity of the substance under test in terms of its equivalent in micrograms per milliliter
of histamine (free base), based on the dilutions made. The value found must not exceed the limit
established in the monograph.
If no contraction occurs in the above-mentioned test due to the effect of the sample tested, prepare a
new sample solution, adding the amount of histamine corresponding to the maximum limit specified
in the monograph and observe if the contraction produced is proportional to the amount of histamine
added. Consider the test valid if this response is proportional and the reproducibility of the
contractions induced by the dose sequence is confirmed: lower reference standard dose, test substance
solution dose and higher reference standard dose. Otherwise, test for vasodepressor substances.
Solution A 50 mL
Atropine sulfate 0.5 mg
Sodium bicarbonate 1.0 g
Anhydrous dextrose (for parenteral use) 0.5 g
Sufficient water for injections for 1000 mL
Solution A
Sodium chloride 160.0 g
Potassium chloride 4.0 g
Anhydrous calcium chloride 2.0 g
Anhydrous magnesium chloride 1.0 g
Sodium Phosphate Dibasic 0.05 g
Sufficient water for injections for 1000 mL
Reference standard solution. Dissolve, in sterile water for injection, a sufficient and accurately
weighed amount of histamine dihydrochloride to obtain a solution containing the equivalent of 1
mg/mL of histamine (free base). Store under refrigeration in an amber glass container with a ground
lid, protected from light, for one month. On the test day, prepare a reference standard solution
containing the equivalent of 1 μg/mL of histamine (free base), in saline solution.
Method
Carry out the test using a cat weighing not less than 2 kg (weigh adult and healthy cat) (if a female
cat, not pregnant) and anesthetize with chloralose or barbiturate injection that allows for the
maintenance of uniform blood pressure. Immobilize the animal and protect it to prevent loss of body
heat, perform rectal temperature monitoring to maintain physiological limits.
Dissect the femoral or jugular vein, preparing it by inserting a cannula filled with heparin (1000
units/mL of saline solution) for administration of reference standard and sample solutions.
Surgically expose the carotid artery, dissecting it completely from surrounding structures, including
the vagus nerve. Insert a cannula connecting it directly to a mercury manometer or other suitable
device for continuous recording of blood pressure.
Assess the cat's sensitivity to histamine, injecting at uniform ranges of not less than five minutes,
doses corresponding to 0.05 μg (dose A); 0.10 µg (dose B) and 0.15 µg (dose C) of histamine (free
base) per kilogram of body weight. After each administration, immediately wash the cannula by
injecting approximately 0.5 mL of saline solution to remove residual activity. Repeat administration
of dosage B three times to observe response uniformity to the same dose. The animal is considered
apt for the test if the responses to the three dosage levels are clearly differentiated and the responses
to the B dose sequence are approximately similar, corresponding to blood pressure drops of not less
than 2.7 kPa (20 mm of mercury).
Inject two series of four doses, each series consisting of two injections of the dose specified in the
sample monograph, alternated with dose B, always at a uniform range of minimum five minutes.
Measure the change in blood pressure after each injection. Upon analyzing the results, the sample is
considered to meet the test requirements if the mean of its depressor responses is lower than that of
dose B.
Finish the test by administering standard dose C to check that the response remains higher than dose
B: if this does not occur, the test is not valid.
The animal can be used as long as it remains stable and responds adequately to administration of the
reference standard solution.
The quality assurance and manufacturing control provided in best practices must ensure that the
product meets the specified requirements, that is, it meets, in addition to other parameters, the
acceptable limits for microorganisms.
To carry out the test, microbial limits, the most likely type of contamination in different categories of
products and the route of administration must be considered.
Testing nature and frequency varies depending on the raw material and the finished product. Certain
categories must be routinely tested for total microbial contamination, such as: those of vegetable,
mineral and/or animal origin, as well as those with a high water content (aqueous oral solutions,
creams, etc.). For other categories such as synthetic raw materials, tablets, powders, capsules, non-
aqueous liquid products, ointments and suppositories, the test frequency can be established based on
historical data from both environmental and equipment microbiological monitoring tests. Other
criteria to be considered would be microbial load of raw material, manufacturing process, product
formulation and the results of water activity determination, when applicable. Low water activity
results (less than or equal to 0.75 measured at 25°C), as well as low or high pH, absence of nutrients
and addition of preservatives contribute to prevent microbial contamination. These parameters must
be considered when establishing a minimum frequency for carrying out microbiological tests.
The efficacy and absence of toxicity of the inactivating agent for the considered microorganisms must
be demonstrated. If using surface-active substances in sample preparation, the absence of toxicity for
microorganisms and compatibility with the inactivating agent must also be demonstrated, as described
in Mesophilic microorganisms total count (5.5.3.1.2).
The solutions and culture media described are considered satisfactory to perform the prescribed
microbial contamination limit tests. However, other media can be used that have similar nutrient and
selective properties for the microbial species studied.
Dissolve monobasic potassium phosphate in 500 mL of water, adjust pH to 7.2 ± 0.2 with 4% sodium
hydroxide. Adjust the volume with water, sterilize and store under refrigeration. When using, dilute
the stock solution with water in a proportion of 1 to 800 (v/v) and sterilize.
Washing fluid
Peptic digest meat peptone 1.0 g
Polysorbate 80 1.0 g (if necessary)
Water 1000 mL
Weigh the reagents and dissolve in distilled water under constant agitation. Heat if necessary. Adjust
pH so that it is 7.1 ±0.2. Sterilize in autoclave using validated cycle.
Universal diluent
Monobasic potassium phosphate 3.6 g
Disodium phosphate dihydrate 7.2 g
Sodium chloride 4.3 g
Meat or Casein Peptone 1.0 g
egg yolk lecithin 3.0 g
L-histidine 1.0 g
Polysorbate 80 30.0 g
Purified water 1000 mL
Weigh the reagents and dissolve in distilled water under constant agitation. Heat if necessary. Adjust
pH so that it is 6.8 ±0.2. Sterilize in autoclave using validated cycle.
Weigh the reagents and dissolve in distilled water under constant agitation. Heat if necessary. Adjust
pH so that it is 7.6 ±0.2. Sterilize in autoclave using validated cycle.
MacConkey Broth
Pancreatic gelatin hydrolysate 20.0 g
Lactose monohydrate 10.0 g
dehydrated bovine bile 5.0 g
Bromocresol purple 10.0 mg
Purified water 1000 mL
pH 7.3 ± 0.2. Sterilize in autoclave using validated cycle.
MacConkey Agar
Pancreatic gelatin hydrolysate 17.0 g
Peptone (meat or casein) 3.0 g
Lactose monohydrate 10.0 g
Sodium chloride 5.0 g
dehydrated bovine bile 1.5 g
Neutral red 30.0 mg
Crystal violet 1.0 mg
Agar 13.5 g
Purified water 1000 mL
pH 7.1 ± 0.2. Boil for one minute under constant agitation. Sterilize in autoclave using validated
cycle.
Cetrimide agar
Pancreatic gelatin hydrolysate 20.0 g
Magnesium chloride 1.4 g
Dipotassium sulfate 10.0 g
Cetrimide 0.3 g
Agar 13.6 g
Purified water 1000 mL
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
Glycerol 10.0 mL
Boil for one minute under constant agitation. Adjust pH to 7.2 ±0.2. Sterilize in autoclave using
validated cycle.
Disperse 39 g in 1000 mL of water. pH 5.6 ± 0.2. Sterilize in autoclave using validated cycle. If pH
3.5 is desired, add approximately 14 mL of sterile 10% (w/v) tartaric acid solution to medium cooled
at 45°C to 50°C.
Columbia Agar
Pancreatic casein hydrolysate 10.0 g
Peptic digestion meat peptone 5.0 g
Heart pancreatic digest 3.0 g
Yeast extract 5.0 g
Maize starch 1.0 g
Sodium chloride 5.0 g
Agar, according to gelling power 10.0 g – 15.0 g
Purified water 1000 mL
Allow the agar to swell and dissolve by heating to boiling under constant agitation. Adjust pH to
7.3 ±0.2 if necessary. Sterilize in autoclave using validated cycle. Cool to 45°C to 50°C and add, if
necessary, gentamicin sulfate corresponding to 20mg of gentamicin base, pour into Petri dishes.
This test consists of counting the population of microorganisms that show visible growth, within five
days, on Soybean-casein digest agar at (32.5 ± 2.5) ºC and within seven days, on Sabouraud-dextrose
agar ( 22.5 ± 2.5) °C.
Alternative microbiological methods, including automated ones, can be used as long as their
equivalence with the pharmacopoeial method has been properly validated.
PREPARATION OF SAMPLES
other suitable diluent. If necessary, adjust the pH to 6.0 ± 8.0 with 0.1 M HCl or 0.1 M NaOH solution.
Prepare serial decimal dilutions with the same diluent.
Lipidic-based products:
Plate counting method: Transfer 10 g or 10 mL of the sample mixture to a flask containing not more
than of 5 g of sterile polysorbate 20 or 80 or other non-inhibitory surfactant. Heat, if necessary, at a
temperature between 40°C and 45°C.
Carefully homogenize keeping the temperature from 40°C to 45°C. Add suitable diluent from those
presented in General Conditions (5.5.3.1.1) – Solutions and culture media, previously heated, in the
amount necessary to obtain a 1:10 dilution of the initial product.
Homogenize carefully, maintaining a maximum temperature of 40°C to 45°C for the time necessary
to form an emulsion; in any case, not more than 30 minutes. Adjust pH between 6.5 to 7.5 if necessary.
Prepare serial decimal dilutions with the same diluent added to polysorbate 20 or 80.
Transfer 10 g of the sample mixture to make a 1:10 dilution in Soybean-casein digest broth containing
0.1 sodium tetradecyl sulfate, heated at 40°C to 45°C. Homogenize until homogeneous mixture.
Homogenize carefully, maintaining temperature for the time necessary to form an emulsion; in any
case, not more than 30 minutes. If necessary, adjust pH to 6.5 to 7.5. Prepare serial decimal dilutions
with the same diluent added to 0.1% sodium tetradecyl sulfate.
Aerosols: cool not less than 10 containers of the product in a mixture of alcohol and dry ice for one
hour. Open the containers and place them at room temperature for the propellant to be eliminated.
Remove 10 g or 10 mL from the containers and transfer the product to filtration apparatus or to a
flask containing a pH 7.2 phosphate buffer solution or other suitable diluent to obtain a 1:10 dilution.
If necessary, adjust pH to 6.0 to 8.0. Prepare serial decimal dilutions with the same diluent.
Gelatin: transfer 10 g of the sample mixture to a vial containing sterile water heated at 40°C to 45°C
and allow to stand for one hour (1:10 dilution). Then transfer the flask to water bath at 45°C, shaking
vigorously at frequent ranges. If necessary, adjust pH to 6.0 to 8.0. Prepare serial decimal dilutions
in sterile water.
Transdermal device: with sterile tongs, remove the protective film from 10 transdermal devices and
place them, adhesive side up, on sterile plates and cover the adhesive side with sterile gauze. Transfer
the 10 devices to a minimum of 500 mL of pH 7.0 Sodium Chloride-Peptone Buffer Solution
containing an appropriate inactivating agent such as polysorbate 80 or soy lecithin. Homogenize
vigorously for not more than 30 minutes.
Correlates:
Cotton and gauze: transfer three 3.3 g portions from the most internal parts of the samples to pH 7.0
Sodium chloride-peptone buffer solution containing an appropriate inactivating agent. Prepare serial
decimal dilutions with the same diluent.
Other correlates: transfer 10 units whose shape and size allow for fragmentation or total immersion
in not more than 1000 mL of pH 7.0 sodium chloride-peptone buffer solution or other suitable diluent.
Allow to be in contact between 10 and 30 minutes. Prepare serial decimal dilutions with the same
diluent. For those that cannot be fragmented or immersed, aseptically introduce 100 mL of pH 7.0
Sodium Chloride-Peptone Buffer Solution in the container. Homogenize. Use 0.45 μm membrane
filtration method.
The preparation method depends on the physical characteristics of the product to be tested. If none of
the procedures described are satisfactory, develop a suitable procedure. Some products may require
more heat in sample preparation, but sample preparation should not exceed 48°C.
PRODUCT ANALYSIS
Sample quantity
The quantity to be tested may be reduced in the case of active substances that are formulated under
the following conditions: the quantity per unit dose (example: tablet, capsule) is less than or equal to
1 mg. In this case, the quantity of sample to be tested must not be less than the quantity present in 10
unit doses.
For products where the batch size is extremely small (i.e., less than 1000 mL or 1000g), the quantity
to be tested must be 1.0% of the batch or less when justified or authorized.
For products where the total number of units in the lot is less than 200, use two units or one unit if
the batch is less than or equal to 100 units.
When sampling products in process, collect three samples from the beginning, four from the middle
and three from the end of the process. Carry out the test on the mixture of these samples.
PROCEDURES
The determination can be carried out by the Membrane Filtration, Plate Count or Multiple Tube
Method (NMP). The latter is reserved for bacterial determinations that cannot be carried out by one
of the other methods and when the product is expected to have a low bacterial density.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
The choice of method is determined by factors such as the product nature and the expected number
of microorganisms, with chosen method being properly validated.
MEMBRANE FILTRATION
Use filtration apparatus that allows for the transfer of the membrane to the culture media. Cellulose
nitrate membranes, for example, can be used for aqueous, oily or weak alcoholic solutions, and
cellulose acetate membranes, for strong alcoholic membranes. Prepare the sample using the most
suitable method previously determined.
Transfer 10 mL, or the amount of dilution representing 1 g or 1 mL of the sample to be tested, to two
membranes and filter immediately. If necessary, dilute the sample to obtain a colony count between
10 and 100 CFU. Wash membranes at least three times with approximately 100 mL of the appropriate
wash fluid. Transfer one of the membranes to the surface of a plate containing Soybean-casein digest
agar, incubate at (32.5 ± 2.5) °C for three to five days to determine the number of total aerobic
microorganisms. Transfer the other membrane to the surface of a plate containing Sabouraud-
dextrose Agar and incubate at (22.5 ± 2.5) °C for five to seven days for the determination of molds
and yeasts.
When analyzing transdermal devices and medical products, separately filter 10% of the preparation
volume, according to the product suitability procedure, and proceed with washing and incubation as
described above.
PLATE COUNT
Depth method - Add 1 mL of the sample prepared as described in Sample preparation, to a Petri dish
and pour, separately, 15 mL to 20 mL of Soybean-casein digest agar and Sabouraud-dextrose agar
kept at 45 °C to 50°C. Use two plates for each medium and dilution. Incubate plates containing
Soybean-casein digest agar at (32.5±2.5) °C for three to five days and plates containing Sabouraud
dextrose Agar at (22.5±2.5) °C for five to seven days for determination of the number of total aerobic
microorganisms and molds and yeasts, respectively. Only plates with a number of colonies lower than
250 (bacteria) and 50 (molds and yeasts) per plate should be considered for results recording. Use the
arithmetic mean of the plates of each medium and calculate the number of CFU per gram or mL of
the product.
Calculation example:
Dilution Colonies per plates CFU/g or mL
1:100 293 2.93 x 104
1:100 100 1.00 x 104
1:1000 41 4.10 x 104
If the number of colonies on the plates of all dilutions is less than 20, record the count corresponding
to the lowest dilution and express it as CFU/g or mL. If plates from all dilutions show no colonies,
record the count as less than once the corresponding lowest dilution. For example, if no growth is
detected at the 1:100 dilution, express the count as less than 100 CFU/g or mL.
Prepare the sample according to product suitability procedures. Prepare 1:10; 1:100; 1:1000 dilutions.
Transfer 1 mL of each dilution to three tubes with 9 mL of Soybean-casein digest broth. Incubate all
tubes at (32.5 ± 2.5) °C for three to five days. Record the number of positive tubes and the number of
negative tubes.
If the sample nature makes reading difficult, a suspension for example, perform a subculture for the
same broth or for Soybean-casein digest agar for two days at the same temperature.
Determine the most probable number of viable microorganism per gram or milliliter of the product
according to information on Table 1.
Alternative microbiological methods, including automated ones, can be used as long as their
equivalence with the pharmacopoeial method has been properly validated.
PROCEDURE
Sample preparation and pre-incubation: prepare the sample using a 1:10 dilution of minimum 1 g or
1 mL of the product to be tested, as described in Mesophilic microorganisms total count (5.5.3.1.2) ,
using Soybean-casein digest broth (Dilution A) as diluent. Homogenize and incubate at (22.5 ±
2.5) °C for two hours and not more than five hours (time required to reactivate the bacteria, but not
enough to stimulate the microorganism to multiply).
Quantitative test (selection and subculture): dilute the appropriate amount of Dilution A into the
Mossel Enterobacteria enrichment broth to obtain 0.1 dilutions; 0.01 and 0.001 g (or 0.1; 0.01 and
0.001 mL) of the product to be tested. Incubate at (32.5 ± 2.5) °C for 24 to 48 hours. For each positive
tube, subculture on Glucose Neutral Red Violet Agar. Incubate at (32.5
2.5 ) °C for 18 to 24 hours.
Table 1 – Interpretation of quantitative test results for bile tolerant gram-negative bacteria.
Results for product quantity of Probable number of bacteria per gram or
0.1 g or 0.1 mL 0.01 g or 0.01 mL 0.001 g or 0.001 mL milliliter of product
+ + + Over 103
+ + - Less than 103 and more than 102
+ - - Less than 102 and more than 10
- - - less than 10 g
Escherichia coli
Sample preparation and pre-incubation: prepare the sample using a 1:10 dilution of not less than 1 g
of the product to be tested, as described in Mesophilic microorganisms total count (5.5.3.1.2).
Use 10 mL of the dilution for 90 mL of enrichment broth (Soybean-casein digest broth) or an amount
corresponding to 1 g or 1 mL. Homogenize and incubate at (32.5 ± 2.5) °C for 18 to 24 hours.
Selection and subculture: homogenize and transfer 1 mL of the enriched sample to 100 mL of
MacConkey Broth. Incubate at (43 ± 1) °C for 24 to 48 hours. Carry out subculture on MacConkey
Agar plate and incubate at (32.5 ± 2.5) °C for 18 to 72 hours.
Salmonella
Sample preparation and pre-incubation: prepare the sample using a 1:10 dilution of not less than 10 g
or 10 mL of the product to be tested, as described in Mesophilic microorganisms total count
(5.5.3.1.2). Homogenize and incubate at (32.5 ± 2.5) °C for 18 to 24 hours.
Selection and subculture: homogenize and transfer 0.1 mL of the content to 10 mL of Salmonella
Rappaport Vassiliadis enrichment broth. Incubate at (32.5 ± 2.5) °C for 18 to 24 hours. Carry out
subculture on a plate containing Xylose Lysine Deoxycholate Agar and incubate at (32.5±2.5) °C for
18 to 48 hours.
Interpretation: The growth of well-developed red colonies with or without a black center indicates
probable presence of Salmonella which must be confirmed by microbial identification tests. The
product meets the test if no growth of such colonies is observed or if the microbial tests are negative.
Pseudomonas aeruginosa
Sample preparation and pre-incubation: Prepare the sample using a 1:10 dilution of not less than 1
g of the product to be examined, as described in Mesophilic microorganisms total count (5.5.3.1.2).
Use 10 mL of the dilution for 90 mL of Soybean-casein digest broth or an amount corresponding to
1 g or 1 mL. Homogenize and incubate at (32.5 ± 2.5) °C for 18 to 24 hours.
When testing the transdermal device, filter 50 mL of Soybean-casein digest broth through sterile
membrane and transfer the membrane to 100 mL Soybean-casein digest broth. Incubate at (32.5 ±
2.5) °C for 18 to 24 hours.
Selection and subculture: homogenize and transfer a loop to a plate containing Cetrimide Agar.
Incubate at (32,5 ± 2,5) °C for 18 to 72 hours. Colony growth indicates probable presence of
Pseudomonas aeruginosa which must be confirmed by microbial identification tests. The product
meets the test if no growth of such colonies is observed or if the identification tests are negative.
Staphylococcus aureus
Sample preparation and pre-incubation: Prepare the sample using a 1:10 dilution of not less than 1
g of the product to be examined, as described in Mesophilic microorganisms total count (5.5.3.1.2).
Use 10 mL of the dilution for 90 mL of enrichment broth (Soybean-casein digest broth) or an amount
corresponding to 1 g or 1 mL. Homogenize and incubate at (32.5 ± 2.5) °C for 18 to 24 hours.
When testing the transdermal device, filter 50 mL of enrichment broth through sterile membrane and
transfer the membrane to 100 mL of Soybean-casein digest broth. Incubate at (32.5 ± 2.5) °C for 18
to 24 hours.
Selection and subculture: homogenize and transfer a loop to a plate containing Mannitol Salt Agar.
Incubate at (32,5 ± 2,5) °C for 18 to 72 hours.
Interpretation: the growth of yellow or white colonies surrounded by a yellow zone indicates probable
presence of S. aureus which must be confirmed by microbial identification tests.
The product meets the test if no growth of such colonies is observed or if the identification tests are
negative.
Clostridium
Selection and subculture: transfer a loop of each flask to the plate containing Agar Columbia.
Incubate in anaerobiosis at (32.5±2.5) °C for 48 hours.
Candida albicans
Sample preparation and pre-incubation: prepare the sample using a 1:10 dilution of not less than 1 g
or mL of the product to be tested, as described in Mesophilic microorganisms total count (5.5.3.1.2).
Use 10 mL of the dilution to 90 mL of Sabouraud-dextrose Broth. Incubate at (32.5 ± 2.5) °C for
three to five days.
Selection and subculture: transfer a loop to a plate containing Sabouraud-dextrose Agar or Candida
Selective Agar according to Nickerson. Incubate at (32.5 ± 2.5) °C for 24 to 48 hours.
The suitability test protocol should adapt the microbial limit test, sample preparation, type of culture
medium and buffer solutions, number and type of membrane wash solution as well as incubation
conditions. This protocol requires the use of microorganisms for microbial recovery testing.
During the adaptation, demonstrate that the choice of method for qualitative and/or quantitative
estimate of viable microorganisms is sensitive, accurate and reliable and that it is capable of
eliminating any interference or inhibition during the recovery of viable microorganisms.
Revalidate the suitability method if the test conditions are modified and/or changes occur in the
product that could affect it.
For indication purposes, the microorganisms available on the ATCC were listed. The same
microorganisms can also be obtained from other sources: CIP, NBRC, NCIMB, NCPF, NCTC,
NCYC, IMI and IP. The correspondence between the microorganisms and the addresses of the entities
that provide them is indicated in Microorganisms used in tests and assays (5.5.3.5).
The lyophilized cultures must be rehydrated according to instructions from suppliers and maintained
by transfers to fresh culture media or by freezing or cooling process for period of storage that
maintains the culture original characteristics.
For the media indicated on Table 3, inoculate a small amount of microorganism, below 100 CFU.
Use a plate or tube for each microorganism.
Test each lot of culture medium for its nutritional capacity as described below: Liquid culture
medium: inoculate less than 100 CFU of the test microorganism in the culture medium indicated.
Incubate at adequate temperature and observe the visible growth, comparing with a (blank) control
of the same culture medium.
Solid culture medium: inoculate each plate that has the culture medium indicated with less than 100
CFU of the test microorganism. Incubate at adequate temperature and compare the growth achieved,
which must not be below 50% in relation to the standardized inoculum.
Negative control: to check the sterility of culture media, put them in incubation for no less than 72
hours in adequate temperature. There must not be growth of microorganisms.
Add to the sample diluted and to the control (diluent without sample), as described on Preparation of
sample, in Total count of the amount of mesophilic microorganisms (5.5.3.1.2), a sufficient amount
of microorganism to obtain a concentration of no more than 100 CFU/mL. The inoculum suspension
volume must not exceed 1.0% of the volume of the product diluted.
The capacity of the culture medium to detect microorganisms at the presence and absence of the
sample must be demonstrated.
To demonstrate the microorganism recovery in the product, use the lowest dilution factor possible. If
the recovery is not adequate, an alternative method, such as neutralization, dilution or filtration, must
be executed.
The number of microorganisms recovered in the diluted sample is comparable with the number of
microorganisms in control.
If the growth is inhibited (reduction lower than 50%), modifications must be made to the counting
procedure to ensure the validity of results. The modifications include:
• Increase the volume of the diluent or culture medium, keeping the product amount constant.
• Incorporate a specific neutralizing agent or an universal neutralizing agent.
• Associate both procedures above.
• Conduct membrane filtration.
If the modifications in the neutralization method are ineffective, it is possible to explain that the
failure is due to the product’s antimicrobial activity, which does not allow the development of the
control microorganism tested.
B) Neutralizing agents
Neutralizing agents for inhibition of the antimicrobial activity must be added to the diluent selected
or to the culture medium, preferably before the sterilization (Table 2). Demonstrate its efficacy and
absence of toxicity to the test microorganism by using diluent with neutralizer and product and
conducting a blank with diluent and neutralizer, respectively.
Conduct the tests separately for each test microorganism listed on Table 3. Use the sample as
prepared on Inoculation of test microorganisms in the sample.
A) Membrane filtration
Use a filtrating membrane with 0.45 μm of pore diameter and proven retention effectiveness.
Cellulose nitrate membranes, for example, can be used for aqueous, oily or weakly alcoholic
solutions, and cellulose acetate membranes, for strongly alcoholic membranes. Use one membrane
for each test microorganism.
From the sample prepared, as described in Inoculation of test microorganisms in the sample, transfer
10 mL to a membrane filtration equipment and filter immediately. Wash the membrane with an
appropriate volume of washing liquid.
For determination of the aerobic microorganism count and for the count of molds and yeasts, transfer
the membranes to Soybean-casein digest agar and Sabouraud dextrose agar, respectively. Incubate
in the conditions described on Table 3 and count the colonies.
B) Plate count
Depth method: use plates with 9 cm of diameter. Add 1 mL of the sample prepared as described on
Inoculation of test microorganisms in the sample and add 15 mL to 20 mL of Soybean-casein digest
agar or Sabouraud dextrose agar kept at 45 °C to 50 °C. For each microorganism tested, use two
plates for each medium and each dilution. Incubate in the conditions described on Table 1. Use the
arithmetic mean of the plates with each culture medium and calculate the number of CFU.
Surface method: for each 9-cm Petri dish, add 15 mL to 20 mL of Soybean casein agar or Sabouraud
dextrose agar and let it solidify. Dry the plates. Add to the culture medium surface 0.1 mL of the
sample prepared as described in inoculation of the microorganism in the sample. For each
microorganism tested, use two dishes. Count and calculate the CFU number.
From the sample prepared as described in Inoculation of test microorganisms in the sample (1:10),
prepare dilutions 1:100 and 1:1000. Transfer 1 mL of each dilution to three tubes with 9 mL of
Soybean Casein Broth each. If necessary, add inactivating agent.
Incubate all tubes at (32.5 ± 2.5) °C for no more than five days. Write down the number of positive
tubes. If the sample nature makes reading difficult, execute a subculture to other tubes with the same
culture medium or for Soybean-casein digest agar for two days at the same temperature. Determine
the most probable number of microorganism per gram or milliliter of the product according to
information on Table 3.
When the membrane filtration method and the plate count method are employed, the number of
colonies obtained must be no less than 50% (factor 2) of the initial inoculum for each microorganism
in the absence of product, and the number of colonies obtained in the diluent must be no less than
50% (factor 2) of the standard inoculum. When the MPN method is employed, the value calculated
is in the confidence interval of 95% of the results obtained.
General conditions
Neutralize the sample conveniently if it has antimicrobial activity. If a surfactant agent is used for the
sample preparation, demonstrate absence of toxicity for the microorganisms and its compatibility
with the inactivating agent, as described in Neutralization/removal of antimicrobial activity from item
Total count of the amount of mesophilic microorganisms from this general method.
Microorganisms isolated from the environment or other species can be included in challenge tests,
especially if they represent contaminants that may be introduced during the product manufacturing
or during the product use.
The lyophilized cultures must be rehydrated according to instructions from suppliers and maintained
by transfers to fresh media or by freezing or cooling process for duly qualified storage periods.
Use standardized suspensions of the test strains as established below. Employ maintenance technique
so that the inoculum does not exceed five passages of the original cultivation. Cultivate each
microorganism (bacterium and fungus) separately.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
Use the Sodium chloride-peptone buffer solution pH 7.0 or the Phosphate buffer solution pH 7.2 to
prepare the suspensions of microorganisms. When preparing the solution of A. brasiliensis spores, add
to the buffer solution 0.05% of polysorbate 80. Use the suspensions within two hours or within 24 hours if
maintained at temperature of 2 °C to 8 °C.
Microorganisms
A) Aerobic microorganisms:
Perform subcultures separately in tubes with culture medium Soybean-casein broth or Soybean-
casein digest agar at (32.5 ± 2.5) °C for 18 to 24 hours. Cultivate Candida albicans in Sabouraud
dextrose agar at (22.5 ± 2.5) °C for two to three days. Use Sodium chloride-peptone buffer solution
pH 7.0 or Phosphate buffer solution pH 7.2 to prepare the suspensions. Use them within two hours
or within 24 hours if stored at 2 °C to 8 °C.
B) Anaerobic microorganism:
Cultivate the strain Clostridium sporogenes under anaerobic conditions in Reinforced Clostridial
medium at (32.5 ± 2.5) °C for 24 to 48 hours. As an alternative method, perform dilutions of a
suspension of vegetative cells from Clostridium sporogenes. This suspensions of spores can be used
as inoculum if maintained at 2 °C to 8 °C for an adequate period..
For the culture media indicated on Table 3, inoculate a small amount of test microorganism, (no more
than 100 CFU). Use a Petri dish or a tube for each microorganism. Each lot of culture medium
sterilized must be tested for its capacity to promote growth of microorganisms, as described below.
Liquid culture medium: inoculate less than 100 CFU of the test microorganism in the culture medium
indicated. Incubate at adequate temperature and observe the visible growth, comparing with a (blank)
control of the same culture medium.
Solid culture medium: inoculate each plate that has the culture medium indicated with less than 100
CFU of the test microorganism. Incubate at temperature. The growth obtained must have the standard
characteristics of the microorganisms in the medium used.
Negative control
To check the assay conditions, conduct a test on the sterility of culture media. There must not be
growth of microorganisms.
For each product to be analyzed, conduct the test as described on Procedure, in Study of pathogenic
microorganisms (5.5.3.1.3).
When homogenizing, add each strain described in the growth promotion. Inoculate the
microorganisms individually in inoculums with no more than 100 CFU. The test must be conducted
in the smallest period of time.
The microorganisms must be detected by the reactions indicated in the corresponding paragraph,
described on Procedure, in Study of pathogenic microorganisms (5.5.3.1.3).
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
If the product has antimicrobial activity and it is necessary to modify the methodology, proceed as
stated in Neutralization/removal of antimicrobial activity from this chapter, using Soybean casein
broth as diluent.
Quality assurance and production controls must be such that the microorganisms capable of
proliferating and contaminating the product are within the limits specified. The microbial limits must
be adequate to several product categories that reflect the most likely type of contamination introduced
during the manufacturing, as well as the route of administration, the end consumer (neonates,
children, seniors, debilitated people), use of immunosuppressive agents, corticosteroids and other
factors. When assessing the results from microbiological tests, the number and types of
microorganisms present must be considered in the context of use of the product proposed.
Based on historical data from microbiological monitoring tests, low microbial burden of the raw
material, aqueous composition, manufacturing process, formulation, the frequency of the test for
determining the microbial limit can be changed for the pharmaceutical dosage forms if they present
water activity (Aa) below 0.75 measured at 25 °C. For the correlates, consider as microbial limit the
ones expressed according to the route of application.
Extending this result to what remains of the lot requires the security that all units from the same lot
have been prepared in order to ensure a high probability that the entire lot would be approved on the
test. Obviously, this depend on the precautions taken during the operational manufacturing processes,
according to Good Manufacturing Practices.
For conducting the sterility test, it is important that the people are adequately trained and qualified.
The tests must be conducted under aseptic conditions using, for example, a Class II type A biosafety
cabinet, which must be installed in a clean area, with classification compatible with the environmental
control requires necessary for conducting the sterility test. For sterility tests on oncogenic drugs,
mutagenic drugs, antibiotics, hormones, steroids and others, the tests must be conducted in the class
II type B2 biosafety cabinet, which has an exhaust system external to the laboratory environment.
Tests must not be conducted under direct exposure to ultraviolet light or in areas under treatment with
aerosols. The conditions must be adequate in order to avoid accidental sample contamination during
the test, and also not affect the detection of possible contaminants. Environmental controls of the
work areas must be executed regularly (air and surface control, particle counts, determination of speed
and direction of air flow, among others).
CULTURE MEDIA
The culture media used for sterility tests are Fluid thioglycolate medium and Soybean casein broth.
The first is used primarily for culture of anaerobic bacteria, although it may also detect the growth of
aerobic bacteria. The second is adequate for culture of yeasts, fungi and aerobic bacteria. The media
used must meet the requirements from Tests for promotion of growth of culture media. Prepare the
culture media as described below. Dehydrated formulations can also be used, and it is necessary to
demonstrate that, after reconstitution according to the manufacturer’s indications, the requirements
from Tests for promotion of growth of culture media are met. The culture media must be sterilized by
a validated process.
Mix L-cystine, sodium chloride, dextrose, yeast extract and casein from pancreatic digestion with
1000 mL of purified water and heat until complete dissolution. Dissolve the sodium thioglycolate or
thioglycolic acid in this solution and adjust the pH with sodium hydroxide M so that, after the
sterilization, the solution pH is 7.1 ± 0.2. If there is need for filtration, heat the solution again, without
letting it reach ebullition, and filter, still warm, in a paper filter. Add the resazurin sodium solution,
homogenize and distribute in adequate vials. The medium must present a pink color on its surface
that does not exceed one third of the height of its liquid mass. In case of obtaining a medium with
pink color in more than one third of its liquid mass, restore the medium by a single heating in water
bath or in flowing vapor.
Sterilize employing a validated process. If it is not used immediately, store at temperature between 2
°C and 25 °C according to guidance from the manufacturer. Do not use the medium for a storage
period superior to the one it was validated for. The Fluid thioglycolate medium must be incubated at
(32.5 ± 2.5) °C under aerobic conditions.
Proceed as described for Fluid thioglycolate medium without adding agar and resazurin sodium. The
pH after sterilization is 7.1 ± 0.2. The Alternative fluid thioglycolate medium must be incubated at
(32.5 ± 2.5) °C under anaerobic conditions.
Dissolve all components in purified water, heating slowly. Cool down at room temperature and adjust
the pH with sodium hydroxide M so that, after sterilization, the solution pH is 7.3 ± 0.2. If necessary,
filter for medium clarification. Distribute in adequate vials and sterilize employing a validated
process. If it is not used immediately, store at temperature between (22.5 ± 2.5) °C or according to
guidance from the manufacturer. Do not use the medium for a storage period superior to the one it
was validated for. The Soybean casein broth must be incubated at (22.5 ± 2.5) °C under aerobic
conditions.
In cases when the culture media are used for the sterility test of penicillins and cephalosporins through
the direct inoculation method, the preparation of Fluid thioglycolate medium and of Soybean casein
broth must be modified as described below. Transfer, aseptically, to sterilized vials with each medium
a sufficient amount of β-lactamase to inactivate the antibiotic present in the sample. A representative
number of vials having medium with β-lactamase without sample must be incubated during the test
period (negative control). Positive controls must also be included to check if all the penicillin or
cephalosporin was inactivated. Proceed to the validation test for bacteriostasis and fungistasis, using
Staphylococcus aureus (ATCC 6538) as test microorganism. The observation of typical microbial
growth is a confirmation that the concentration of β-lactamase used is adequate.
STANDARDIZATION OF INOCULUM
Usually, it is necessary to make adjustments to obtain a specific density of viable microbial cells (no
more than 100 CFU) in the culture medium. To establish a volume that has the recommended density
of cells, serial dilutions must be made from a stock suspension, proceeding to count in plates to
determine the microbial density obtained with each dilution.
If the procedure is properly standardized, it is possible to reproduce the results with the same
microbial strain.
It is recommendable to use subcultures of microorganism up to no more than five transfers, from the
original culture.
Note: the culture media used in the standardization of inoculum are the ones described in the chapter
Total count of the amount of mesophilic microorganisms (5.5.3.1.2) for each microorganism.
Procedure
Using a cultivation loop, transfer the growth of the specific microorganism to a test tube with agar
slant indicated for its growth. Seed the culture over the surface of agar slant, in order to obtain an
uniform growth film. Incubate in optimal conditions for growth of the test microorganism.
As a suggestion of dilutions for the inoculum, after the period of incubation wash the microorganism
growth with 1 mL of 0.9% (w/v) sterile sodium chloride solution or 0.1% (w/v) or sterile peptone
water and transfer to a flask with 99 mL of 0.9% (w/v) sterile sodium chloride solution or 0.1% (w/v)
sterile peptone water – (stock suspension). Homogenize the suspension manually or in a vortex-type
tube shaker.
Prepare serial dilutions (1:100, 1:10000 and 1:1000000) from the stock suspension using 0.9% (w/v)
sterile sodium chloride solution or 0.1% (w/v) or sterile peptone water as diluent. Incorporate 1 mL
of each dilution in a solid medium that is adequate for the microorganism, previously molten and
cooled down at approximately 45 °C. Homogenize and incubate.
Proceed to counting the number of colonies that have developed in the solid medium and select, from
the results, the dilution to be used to obtain no more than of 100 CFU per culture medium vial.
For preparing the fungal suspension, the 0.9% (w/v) sterile sodium chloride solution can be replaced
with sterile purified water.
The culture media used must comply with the tests described below, conducted before or in parallel
with the Sample sterility test.
Sterility
To confirm the sterility, a sample that is representative of each lot of the medium must be incubated
in the conditions specified for 14 days. For a lot of up to 100 units, it is suggested that 3% to 5% of
the samples are submitted to the assay. For a bigger batch, 10 plates or tubes taken randomly must be
tested. There must not be microbial growth.
The existence of microbial growth renders the lot of medium useless for the sterility test.
Promotion of growth
Each lot of culture medium sterilized must be tested for its capacity to promote growth of
microorganisms. Inoculate, separately, in duplicate, tubes of each medium with a volume of inoculum
containing no more than 100 CFU of each microbial strain listed on Table 1 and incubate according
to the conditions specified for each medium. The test for promotion of growth is considered valid if
there is evidence of microbial growth, viewed by turbidity and/or by microscopic methods, after three
days of incubation of media inoculated with bacteria and after five days of incubation of media
inoculated with fungi.
Table 1 – Microorganisms indicated for use in tests for promotion of growth and validation.
Medium Microorganism Strain
Fluid thioglycolate Staphylococcus aureus ATCC 6538, NCTC 10788, NCIMB 9518, CIP 4.83, NBRC
medium 13276
Pseudomonas aeruginosa ATCC 9027, NCIMB 8626, CIP 82.118, NBRC 13275
Clostridium sporogenes ATCC 19404, NCTC 532, CIP 79.3 or ATCC 11437,
NCIMB 14239, CIP 100651, NBRC 14293
Alternative thioglycolate Clostridium sporogenes ATCC 19404, NCTC 532, CIP 79.3 or ATCC 11437,
NCIMB 14239, CIP 100651, NBRC 14293
Soybean casein broth Bacillus subtilis ATCC 6633, NCIMB 8054, CIP 52.62, NBRC 3134
Candida albicans ATCC 10231, NCPF 3179, IP 48.72, NBRC 1594
Aspergillus brasiliensis ATCC 16404, IMI 149007, IP 1431.83, NBRC 9455
Bacteroides vulgatus (ATCC 8482, NCTC 11154) can be used alternatively to Clostridium
sporogenes, when it is not necessary to use a sporulated microorganism.
An alternative to Staphylococcus aureus is the Bacillus subtilis (ATCC 6633, CIP 52.62, NBRC 3134,
NCIMB 8054, NCTC 10400).
STORAGE OF MEDIA
If the media prepared are stored in non-hermetically closed vials, they can be used for one month,
provided that they are tested for promotion of growth within 15 days from the time of use and that
they meet the requisite for the color indicator.
If the media are stored in hermetically closed vials, they can be used for one year, provided that they
are tested for promotion of growth within three months from the time of use and that they meet the
requisite for the color indicator.
Fluid I
Peptone from meat 1.0 g
Purified water 1000 mL
pH after sterilization 7.1 ± 0.2
Dissolve the peptone from meat in purified water, filter or centrifuge for medium clarification, if
necessary, and adjust the pH to 7.1 ± 0.2. Distribute in adequate vials and sterilize employing a
validated process.
Preparation for penicillins or cephalosporins. For conducting the assay on sterility of penicillins or
cephalosporins through the membrane filtration method, add, aseptically, to the sterilized Fluid I a
sufficient amount of β-lactamase to inactivate any residual antibiotic activity in the membrane after
filtering the sample.
Fluid II
For every liter of Fluid I, add 1 mL of polysorbate 80 before the sterilization. Adjust the pH to 7.1 ±
0.2. Distribute in adequate vials and sterilize employing a validated process. Use this fluid for
products that have lecithin or oil and for healthcare products.
Fluid III
Homogenize all components and heat, slowly, until dissolution. Filter, if necessary, and adjust the pH
to obtain, after the sterilization, the value of 6.9 ± 0.2. Distribute in adequate vials and sterilize
employing a validated process.
Before establishing a procedure for the test on sterility of pharmaceutical ingredients, medicines or
healthcare products, it is necessary to ensure that any bacteriostatic or fungistatic activity inherent to
the product has no adverse influence over the test reliability, demonstrating that the procedure
employed is adequate for the product being examined.
The test of validation for bacteriostasis and fungistasis must be conducted when the sterility test is
executed for the first time for a product and whenever there are modifications in the product
formulation and/or in the experimental conditions of the test. The validation must be done before the
test on sterility of the product being examined.
Procedure
To conduct the validation test, proceed as described in Procedures for the sterility test, employing
exactly the same methods, except for the following modifications.
Note: for both methods described below, use the microorganisms previously specified (Table 1).
Conduct tests on Promotion of growth as positive control. Incubate all vials with the media for no
more than five days.
Membrane filtration method. After transferring content from the vial(s) to be tested (as specified on
Table 3) for the filtration device, add no more than 100 CFU of the test microorganism to the last aliquot
of the sterile filter used for membrane washing.
Direct inoculation method. After transferring the content from the vial(s) to be tested (as specified on
Table 3) to vials with the culture media, add no more than 100 CFU of the test microorganisms to
the media.
Interpretation
If the growth of microorganisms obtained after incubation is visibly comparable with the one obtained
on positive control (vial without addition of sample), the sample does not present antimicrobial
activity under the test conditions or such activity was satisfactorily eliminated. The sterility test can
then be conducted without the need for modifications.
If the growth of microorganisms is not obtained in the presence of sample, or if it is not visibly
comparable with the one obtained on positive controls, the sample presents antimicrobial activity that
was not satisfactorily eliminated under the test conditions. In this case, modifications must be made
in the test conditions to eliminate the antimicrobial activity, such as dilution, use of neutralizing
substances, increase in the number of washes on the membrane filtration method, or a combination
of them. The validation test must be repeated to check if the antimicrobial activity was eliminated by
the modification proposed.
The sterility test can be conducted using the membrane filtration or direct inoculation methods
according to the nature of the product, except when one of the methods is specified in the individual
monograph. In both cases, appropriate negative controls must be included.
Before proceeding to the test, make the asepsis of the external surface of vials and ampoules, dipping
them into an adequate antiseptic solution, or employing other procedures for external disinfection of
vessels, such as, for example, hydrogen peroxide vapors. In case of articles which packages do not
resist this treatment, make the asepsis of samples with a fabric that does not release particles, soaked
in antiseptic solution.
Sampling
If not specified in the individual monograph, test the number of units of the sample as listed on Table
2. If the sample units present content in sufficient amount (Table 3), the content from each unit can
be divided into two equal portions for each type of culture medium used. If the sample units do not
present content in sufficient amount for each medium, separate double the number of units specified
on Table 2 for conducting the test.
a
sampling specified considering that the content of a vessel is sufficient to inoculate both culture media.
b
for raw materials, the satisfactory sampling can be based on the square root of the total number of vessels in the lot.
Use filtering membranes with nominal porosity of no more than 0.45 μm which efficiency in retaining
microorganisms has been established. Cellulose nitrate filters, for example, are used for aqueous, oily
and weakly alcoholic solutions, and cellulose acetate membranes, for strongly alcoholic membranes,
for example. Specially adapted filters can be requested for certain products, such as antibiotics.
For extremely aggressive oncologic products – replace the cellulose ester membrane with
polyvinylidene difluoride (PVDF) or polytetrafluoroethylene (PTFE).
The procedures described below apply to membranes with diameter of approximately 50 mm. If filters
with different diameters are used, the volumes of dilutions and washes must be adjusted according to
the diameter of the membrane used. The filtration device and the membrane are sterilized by an
adequate process. The device has such a setup that the solution to be examined can be introduced and
filtered under aseptic conditions. The filtration device must also allow the aseptic removal of the
membrane for its transfer to the culture medium, or be adequate for proceeding with the incubation
after adding the culture medium to the own device. The type of fluid used in membrane washing
depends on the product nature, being specified in the individual monograph, whenever it is the case.
Negative controls or blanks must be included for the fluids and solvents used, for which no microbial
growth must be observed. It is also necessary to verify if the fluids used do not present antimicrobial
activity in the test conditions.
Liquids miscible in aqueous vehicles: transfer a small amount of sterile diluent, such as Fluid I, to the
membrane and filter. The diluent must have neutralizing or inactivating substances, such as in the
case of antibiotics. Transfer to the membrane the contents from the vessels to be tested or the
appropriate dilution (previously defined in the Validation test for bacteriostasis and fungistasis) in
amounts not inferior to the ones recommended on Tables 2 and 3 and filter immediately. If the
product presents antimicrobial activity, wash the membrane no less than three times, filtering, each
time, the volume of sterile diluent established on Validation test for bacteriostasis and fungistasis.
The amount of washing fluid used must not be superior to five portions of 200 mL, even if during the
validation test it has been demonstrated that such washing cycle does not completely eliminate the
antimicrobial activity. Transfer the entire membrane or cut, aseptically, in two equal parts, to the
media selected, being one half to each. Use the same volumes of medium used in the validation test.
Incubate the media for no less than 14 days.
Oils and oily solutions: use, for each culture medium, the amount of sample specified on Tables 2
and 3. Oils and oily solutions with low viscosity can be filtered without dilution through the dry
membrane. Viscous oils must be diluted in adequate sterile solvent, such as, for example, isopropyl
myristate, provided that it is demonstrated they don’t have antimicrobial activity in the test conditions.
Let the oil penetrate in the membrane, filter using vacuum gradually. Wash the membrane with no
less than three portions of Fluid III. Carry on as described in Liquids miscible in aqueous vehicles.
Pomades and creams: use, for each culture medium, the amount of sample specified on Tables 2 and
3. Pomades with oily base and emulsion of the water in oil type can be diluted to 1.0% in adequate
solvent (isopropyl myristate or another) as describe din the previous item, heating, if necessary, at 40
°C (in exceptional cases, heat up to no more than 44 °C). Filter, as quickly as possible, and carry on
as described in Oils and oily solutions. In case of using isopropyl myristate as diluent, provided that
demonstrated it has no antimicrobial activity in the test conditions, it must be sterilized before use,
by membrane filtration, and its aqueous extract must present pH not below 6.5.
Soluble solids (non-antibiotics): use, for each culture medium, the amount of sample specified on
Tables 2 and 3. Dissolve the product in adequate fluid, such as Fluid I, and carry on as described in
Liquids miscible in aqueous vehicles.
Solids for injectable preparations (non-antibiotics):reconstitute the product as described on the label
and proceed as described for Liquids miscible in aqueous vehicles or Oils and oily solutions, depending
on the case. If necessary, excess diluent can be used to help in the product reconstitution and filtration.
Solid antibiotics for injectable preparations: for packages with less than 5 g, take aseptically, from
each one of the 20 vials recommended, approximately 0.3 g of sample, dissolve in 200 mL of Fluid I
and homogenize. Alternatively, reconstitute the product as described on the label, transfer the
equivalent, in liquid, to 0.3 g of sample and dilute to 200 mL with Fluid I. For packages with 5 g or
more, transfer aseptically, from every six vessels, 1 g of sample to an adequate vial, dissolve in
200 mL of Fluid I and homogenize.
Alternatively, reconstitute the six vials of product as recommended by the manufacturer, transfer an
amount of liquid equivalent to 1 g of sample to an adequate vial, dilute to 200 mL with Fluid I and
homogenize. Carry on as described in Liquids miscible in aqueous vehicles.
Sterile aerosols: for pressurized liquid products, freeze the content in a mixture of ethyl alcohol and
dry ice at no less than -20 °C, for approximately one hour. If possible, before opening the package,
let the propellent escape and transfer the content aseptically to an adequate sterile vial. Add 100 mL
of Fluid II and softly homogenize. Carry on as described in Liquids miscible in aqueous vehicles or
Oils and oily solutions, according to the case.
Syringes already filled, with or without a coupled needle: expel the content from each syringe over
the membrane(s) or in separate vials and then filter. Carry on as described in Liquids miscible in
aqueous vehicles.
Sterile devices: Pass aseptically one volume of Fluid II not inferior to 10% of the volume of each unit
from the total of devices to be tested as established on Tables 2 and 3. Collect the fluid in an adequate
sterile vessel and proceed as indicated for liquids miscible in aqueous vehicles or aqueous solutions
of oils and oily solutions, according to the case. In the case of sterile empty syringes, extract the sterile
diluent from the vessel with the sterile needle, if coupled, or through a sterile needle coupled to
proceed with the assay, and expel the content in a sterile vessel. Proceed as indicated previously.
Transfer, directly and aseptically, to the culture media the amount of product specified on Tables 2
and 3, in such a way that the product volume is not higher than 10% of the culture medium volume,
unless specified differently in the individual monograph or in this section. If the sample presents
antimicrobial activity, conduct the test after neutralizing the activity with an adequate neutralizing
substance or by dilution in sufficient amount of culture medium. When it is necessary to use large
volumes of the product, it is possible to work with concentrated culture medium, prepared taking into
account the dilution subsequent to the product addition. If the vessels can handled it, the concentrated
medium can be added directly to the sample.
Non-oily liquids: transfer the indicated volume of each sample according to Table 3 to tubes
containing fluid thioglycolate medium and soybean casein broth, using a sterile pipette or sterile
syringe and needle. Homogenize the liquid with the medium, without aerating excessively. Incubate
in the conditions specified for each medium for 14 days.
Oily liquids: use a culture medium with appropriate emulsifying agent in a concentration shown to
be adequate in the validation, for example, 1.0 (w/v) polysorbate 80.
Pomades and creams: prepare a sample dilution at 10% using an adequate emulsifying agent added
to a sterile diluent such as Fluid I. Transfer the diluted sample to culture media without emulsifier.
Incubate the inoculated media for no less than 14 days. Observe the media throughout the incubation
period. Homogenize, softly, the culture medium vials with oil, every day, throughout the incubation
period. The vials with Liquid thioglycolate medium or another similar medium must be agitated in
order to not affect the anaerobiosis conditions.
Solids: transfer the amount of sample specified on Tables 2 and 3 or prepare a solution or suspension
of the product adding a volume not superior to 20 mL of sterile diluent to the vessel. Transfer the
material obtained to 200 mL of Fluid thioglycolate medium. Likewise, transfer the same amount of
material to 200 mL of Soybean casein broth and homogenize. Carry on as described for Non-oily
liquids.
Catgut and other surgical sutures: For each medium, use the amount of sample specified on Tables
2 and 3. Open the package aseptically and take three portions of threat for each culture medium. Such
portions must be taken from the beginning, the middle and the end and have 30 cm of length. Cover
each part of the thread with sufficient volume of the media (20 mL to 150 mL).
Purified cotton, gauze, bandage and related material: take from each package of cotton, gauze in roll
or in bandage to be analyzed, with sterile instruments, two portions of 0.1 g to 0.5 g from the
innermost parts of the sample. For materials in individual package, such as gauze pad, take two
individual portions of 0.25 g to 0,5 g, or two total units, in case of small units (e.g.: bandages smaller
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
than 25 mm to 75 mm). Transfer one portion to a tube with 40 mL of Fluid thioglycolate medium and
the other to tubes with 40 mL of Soybean casein broth. Carry on as described for Liquids.
Parenteral devices: For devices in shapes and dimensions that allow their immersion in volume of
medium that does not exceed 1000 mL, make their immersion using the amounts specified on Tables
2 and 3 and proceed as described in Liquids. For very large devices, make the immersion of parts that
come into contact with the patient in a sufficient volume of medium for immersion of all parts. For
catheters which internal and external lumens must be sterile, pass the medium inside the lumen or fill
the lumen with the medium and promote the immersion of the entire device.
During the period of incubation and until its end, examine the media for macroscopic evidence of
microbial growth. If the sample being examined causes turbidity of culture media, preventing the
observation of microbial growth, transfer adequate portions from each vial (no less than 1 mL) to new
vials of the same media 14 days after the beginning of incubation. Incubate the original vials and the
new vials by an additional period of no less than four days. If, at the end of the incubation period,
there is no evidence of microbial growth, the sample being examined complies with the requirement
of sterility. If there is evidence of microorganism growth, the sample does not comply with the
requirement of sterility, unless there is evident fault during the test execution, such as, for example,
contamination not related to the product being analyzed.
The sterility test may be considered invalid if one or more of the following conditions are met.
a) the data on microbiological monitoring of the area where the test was conducted demonstrate fault;
b) a review of the analytical procedures employed during the test reveals fault; c) microbial growth
is observed in negative controls; d) after identification of microorganism(s) isolated from the test, the
growth of such species can be attributed, undoubtfully, to faults related to the material used and/or
techniques employed in the execution of the sterility test.
If considered invalid, the sterility test must be repeated with the same number of units from the initial
test. If, after the test repetition, no microbial growth is observed, the sample complies with the
requirement of sterility. If microbial growth is observed after the test repetition, the sample being
examined does not comply with the requirement of sterility.
When employing the membrane filtration technique, use, whenever possible, the entire content of the
vessel, but no less than the amount indicated on Tables 2 and 3, diluting, when necessary, to
approximately 100 mL with an adequate sterile solution, such as Fluid I.
When employing the direct inoculation technique, use the amounts indicated on Tables 2 and 3,
unless authorized and justified otherwise. The tests for bacteria and fungi are conducted with the same
unit of sample being examined. When the volume or amount in a single vessel is insufficient for
conducting the test, the contents from two or more vessels are used to inoculate the different media.
Due to the fast radioactive decay, it is not feasible to delay the release of some pharmaceutical
products because of the sterility test.
In such cases, the results from sterility tests provide only confirmatory retrospective evidence for
guarantee of sterility and, therefore, depend on the initial methods established in the manufacturing
and in the validation/certification procedures.
International Unit is the specific activity included in an amount (mass) of International Biological
/Standard or International Biological Reference Preparation. The equivalent amount of units for
international use is established, whenever necessary, by the World Health Organization.
International Chemical Reference Substances do not present defined biological activity units. When
biological assays are necessary, the potency of these products is in terms of mass equivalent to the
one from the pure substance.
The number of units, or the equivalent mass of the pure substance, in micrograms, contained in 1 mg
of antibiotic substance is indicated in the monograph from each of the products registered in the
Pharmacopoeia.
It is recommended that (secondary) work standards are prepared and used; however, it is mandatory
that the potency has been determined by an adequate number of comparative assays in relation to a
primary or pharmacopoeial standard, validated by appropriate statistical analysis, and that the data
and results are archived and made available to the relevant inspection for a period that is identical to
the one of the validity of tested products.
For assay on lots of antibiotic substances or which there are national Standard Preparations,
referenced by international organizations, it is mandatory to use these preparations.
SOLUTIONS
Solution 1 (potassium phosphate buffer 1.0%, sterile, pH 6.0) – Dissolve 2.0 g of dibasic
potassium phosphate and 8 g of monobasic potassium phosphate in 800 mL of purified water. If
necessary, adjust the pH to 5.9 – 6.1 with 6 M phosphoric acid or 10 M or potassium hydroxide,
complete the volume to 1000 mL with water and homogenize. Sterilize the solution for 20 minutes in
autoclave at 121 °C.
Solution 2 (potassium phosphate buffer 0.1 M, sterile, pH 8.0) – Dissolve 16.73 g of dibasic
potassium phosphate and 0.523 g of monobasic potassium phosphate in 800 mL of purified water. If
necessary, adjust the pH to 7.9 – 8.1 with 6 M phosphoric acid or 10 M potassium hydroxide, complete
the volume to 1000 mL with water and homogenize. Sterilize the solution for 20 minutes in autoclave
at 121 °C.
Solution 3 (potassium phosphate buffer 0.1 M, sterile, pH 4.5) – Dissolve 13.6 g of monobasic
potassium phosphate in 800 mL of purified water. If necessary, adjust the pH to 4.4 – 4.5 with 6 M
phosphoric acid or 10 M potassium hydroxide, complete the volume to 1000 mL with water and
homogenize. Sterilize the solution for 20 minutes in autoclave at 121 °C.
Solution 4 (potassium phosphate buffer 10%, sterile, pH 6.0) – Dissolve 20.0 g of dibasic
potassium phosphate and 80.0 g of monobasic potassium phosphate in 800 mL of purified water. If
necessary, adjust the pH to 5.9 – 6.1 with 6 M phosphoric acid or 10 M potassium hydroxide, complete
the volume to 1000 mL with water and homogenize. Sterilize the solution for 20 minutes in autoclave at 121
°C.
Solution 5 (potassium phosphate buffer 0.2 M, sterile, pH 10.5) – Dissolve 35.0 g of dibasic
potassium phosphate and add 2.0 g of potassium hydroxide 10 M in 800 mL of purified water. If
necessary, adjust the pH to 10.4 – 10.6 with 6 M phosphoric acid or 10 M potassium hydroxide,
complete the volume to 1000 mL with water and homogenize. Sterilize the solution for 20 minutes in
autoclave at 121 °C.
Solution 6 (0.1 M methanolic hydrochloric acid) – Dilute 10.0 mL of hydrochloric acid 1.0 M in
sufficient methyl alcohol to make 1000 mL.
Solution 7 (isopropyl alcohol solution 80%) – Dilute 800 mL of isopropyl alcohol in sufficient
purified water to make 1000 mL.
Solution 8 (potassium phosphate buffer 0.1 M, sterile, pH 7.0) – Dissolve 13.6 g of dibasic
potassium phosphate and 4.0 g of monobasic potassium monobasic in 800 mL of purified water. If
necessary, adjust the pH to 6.8 – 7.2 with 6 M phosphoric acid or 10 M potassium hydroxide, complete
the volume to 1000 mL with water and homogenize. Sterilize the solution for 20 minutes in autoclave
at 121 °C.
CULTURE MEDIA
Dehydrated culture media, commercially available, which have the same composition as the medium
produced with the ingredients individually indicated for obtaining them when reconstituted with
purified water, according to specifications from the manufacturer, can be used.
Culture medium n. 1 – Dissolve 6.0 g of dry peptone, 4.0 g of casein from pancreatic digestion,3.0 g
of yeast extract, 1.0 g of dextrose and 15.0 g of agar in sufficient purified water to make 1000 mL.
The pH after sterilization must be 6.6.
Culture medium n. 2 – Dissolve 6.0 g of dry peptone, 3.0 g of yeast extract, 1.5 g of meat extract
and 15.0 g of agar in sufficient purified water to make 1000 mL. The pH after sterilization must be
6.6.
Culture medium n. 3 – Dissolve 5.0 g of dry peptone, 1.5 g of yeast extract, 1.5 g of meat extract,
2.5 g of sodium chloride, 1.0 g of dextrose, 3.68 g of dibasic potassium phosphate and 1.32 g of
monobasic potassium phosphate, in sufficient purified water to make 1000 mL. The pH after
sterilization must be 7.0.
Culture medium n. 4 – Dissolve 6.0 g of dry peptone, 3.0 g of yeast extract, 1.5 g of meat extract,
1.0 g of D-glucose and 15.0 g of agar in sufficient purified water to make 1000 mL. The pH after
sterilization must be 6.6.
Culture medium n. 5 – Use culture medium n. 2, but the pH after sterilization must be 7.8.
Culture medium n. 6 – Dissolve 40.0 g of dextrose and 10.0 g of dry peptone in sufficient purified
water to make 1000 mL. The pH after sterilization must be 5.6.
Culture medium n. 7 – Use culture medium n. 1, sterilized and cooled down at 50 °C. Prepare
aqueous solution with 10 mg of neomycin per mL and sterilize by membrane filtration on membrane
with porosity of 0.22 μm. Add, aseptically, a sterile solution of neomycin sulfate, to obtain final
concentration with potency of 100 μg of neomycin per mL of medium.
Culture medium n. 8 – Use culture medium n. 2, but the pH after sterilization must be adjusted to
5.8 to 6.0.
Culture medium n. 9 – Dissolve 17.0 g of casein from pancreatic digestion, 3.0 g of soybean from
papain digestion, 5.0 g of sodium chloride, 2.5 g of dibasic potassium phosphate, 2.5 g of dextrose
and 20.0 g of agar in sufficient purified water to make 1000 mL. The pH after sterilization must be
7.3.
Culture medium n. 10 – Use culture medium n. 9, but adding, instead of 20.0 g, 12.0 g of agar and
10.0 mL of polysorbate 80 (the latter added after heating the medium to dissolve agar, immediately
diluting with water to make 1000 mL). The pH after sterilization must be 7.3.
Culture medium n. 11 – Use culture medium n. 1, but the pH after sterilization must be adjusted to
8.0.
Culture medium n. 12 – Prepare like culture medium n. 1, but adding 300 mg of manganese sulfate
monohydrate (MnSO4.H2O) for every 1000 mL of medium.
Culture medium n. 13 – Dissolve 10.0 g of dry peptone and 20.0 g of dextrose in sufficient purified
water to make 1000 mL. The pH after sterilization must be 5.6.
Culture medium n. 14 – Dissolve 10.0 g of glycerol, 10.6 g of dry peptone, 10.6 g of meat extract
and 3.0 g of sodium chloride in sufficient purified water to make 1000 mL. The pH after sterilization
must be 7.0.
Culture medium n. 15 – Prepare like culture medium n. 14, but adding 17.0 mg of agar for every
1000 mL of medium.
Culture medium n. 16 – Dissolve 15.0 g of casein from pancreatic digestion, 5.0 g of soybean from
papain digestion, 5 g of sodium chloride and 15.0 g of agar in sufficient purified water to make
1000 mL. The pH after sterilization must be 7.3.
Culture medium n. 17 – Dissolve 17.0 g of casein from pancreatic digestion, 3.0 g of soybean
peptone, 2,5 g of dextrose, 5.0 g of sodium chloride and 2.5 g of dibasic potassium phosphate in
sufficient purified water to make 1000 mL. The pH after sterilization must be 7.3.
Culture medium n. 18 – Use culture medium n. 11, but, after heating the solution to dissolve the
ingredients, add 20.0 mL of polysorbate 80. The pH after sterilization must be 8.0.
Culture medium n. 19 – Dissolve 9.4 g of dry peptone, 4.7 g of yeast extract, 2.4 g of meat extract,
15.0 g of sodium chloride, 10.0 g of dextrose and 23.5 g of agar in sufficient purified water to make
1000 mL. The pH after sterilization must be 6.1.
Culture medium n. 20 – Dissolve 40.0 g of dextrose, 10.0 g of dry peptone, 15.0 g of agar and 0.05
g of chloramphenicol (in potency) in sufficient purified water to make 1000 mL. The pH after
sterilization must be 5.6.
Culture medium n. 21 – Use culture medium n. 20, sterilized and cooled down at 50 °C. Add,
aseptically, 2.0 mL of sterile cycloheximide solution for every 100 mL of melted agar. Prepare a
solution with 10,0 mg of cycloheximide per mL, in purified water, and sterilize by membrane
filtration in membrane with porosity of 0.22 μm.
Culture medium n. 22 – Dissolve 15.0 g of dry peptone, 5.0 g of soybean flour from papain
digestion, 4.0 g of sodium chloride, 0.2 g of sodium sulfite, 0.7 g of L-cystine, 5.5 g of dextrose and
15.0 g of agar in sufficient purified water to make 1000 mL. The pH after sterilization must be 7.0.
PREPARATION OF INOCULUM
Recommended microorganisms
For indication purposes, the microorganisms available on the ATCC were listed. The same
microorganisms can also be obtained from other sources: CIP, NBRC, NCIMB, NCPF, NCTC,
NCYC, IMI and IP. The matching between the microorganisms and the addresses from entities that
provide them is indicated in Microorganisms used in tests and assays (5.5.3.5).
Preparation of suspension: transfer the microorganism from a stock culture to tubes with 10 mL of
slant culture medium n. 1. Incubate the tube at 32 °C to 35 °C, for 24 hours. After the incubation,
wash the microorganism growth with 50 mL of the sterile physiological solution.
Standardization of the suspension: dilute the suspension prepared, with sterile physiological solution,
to obtain the transmittance of 25% at the wavelength of 580 nm, using an adequate spectrophotometer
and test tubes with 13 mm of diameter as absorption vat. Determine the amount of suspension to be
added to each 100 mL of agar or nutrient broth to produce clear and defined inhibition zones or a
satisfactory dose/response relationship in the turbidimetric method. The suspensions of
microorganisms submitted to procedure 1 can be stocked at temperature of 4 °C, respectively, for the
following periods: one week, two weeks, two weeks, two weeks, two weeks, six months, one week,
two weeks, and two weeks.
Micrococcus luteus ATCC 14452. Execute as indicated on Procedure 1. However, employ on the tube
with slant medium and on the Roux bottle the culture medium n. 7, incubating the vial for 48 hours.
The suspension can be stocked for two weeks, at temperature not superior to 4 °C.
Execute as indicated on Procedure 1. However, in the preparation of the suspension, use culture
medium n. 12, which incubation time is of five days. In the standardization of suspension, proceed to
thermal shock and standardize the suspension as follows: centrifuge and decant the supernatant liquid.
Resuspend the sediment with 50 mL to 70 mL of sterile physiological solution and heat the
suspension for 30 minutes at 70 °C. Execute tests in plates, to ensure the viability of spores, and
determine the amount that must be added to every 100 mL of medium, to obtain adequate inhibition
zones. The suspension can be stocked for six months, at temperature not superior to 4 °C.
Execute as indicated on Procedure 1. However, incubate the tube with the microorganism for one
week. In the standardization of suspension, proceed to thermal shock and standardize the suspension
as follows: heat the suspension for 30 minutes, at 80 °C. Wash the suspension of spores three times
with 20 mL to 25 mL of sterile water. Resuspend the microorganisms in 50 mL to 70 mL of sterile
water and promote a new thermal shock for 30 minutes at 70 °C. Execute tests in plates, to ensure the
viability of spores, and determine the amount that must be added to every 100 mL of agar, to obtain
adequate inhibition zones. The suspension can be stocked for six months, at temperature not superior
to 4 °C.
Incubate the microorganism for six to eight weeks, at 25 °C, in three-liter Erlenmeyer flasks with
200 mL of culture medium n. 6. Check the growth by sporulation. When the sporulation is 80% or
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
more, collect the conidia from the mycelium layer with a sterile spatula or another adequate
instrument. The conidia will be on the upper part of the floating layer. Keep the conidia in 50 mL of
physiological solution. Determine, experimentally, the amount of conidia for the assay. The
suspension can be stocked for two months, at temperature not superior to 4 °C.
Transfer the microorganism from a stock culture to medium n. 33 and incubate, for 16 to 18 hours, at
37 °C. Determine, experimentally, the amount of microorganisms for the assay. Keep this culture
under refrigeration for no more than 24 hours.
Keep the microorganism in tubes with 10 mL of slant culture medium n. 19. Incubate the tubes at 32
°C to 35 °C, for 24 hours. Inoculate 100 mL of nutrient broth — culture medium n. 13 — and incubate,
for 16 to 18 hours, at 37 °C. Standardize the suspension as described in the Procedure
1. The suspension can be stocked for four weeks, at temperature not superior to 4 °C.
Follow what is indicated on Procedure 1. However, incubate the slant tube with the culture medium
n. 19, at 30 °C, the latter for a period of 48 hours. The suspension can be stocked for four weeks, at
temperature not superior to 4 °C.
Keep the microorganisms in tubes with slant medium with 10 mL of culture medium n. 16 and re-
plate every week. Incubate the tube at 37 °C, for 48 hours. Using 3 mL of sterile physiological
solution, transfer the cultures that grew on agar slant to a 500 mL Erlenmeyer flask, with 100 mL of
culture medium n. 14 and 50 g of glass beads. Homogenize the culture by rotation speed of 130 cycles
per minute, in a radius of 3.5 cm and at temperature of 27 °C, for a period of five days. Determine
the amount of suspension to be added to every 100 mL of agar through assay on plates. The suspension
can be stocked for two weeks at temperature not superior to 4 °C.
* the microorganisms can be used in conditions that ensure no more than five passages of the culture
of origin.
Employ for desiccation of standards the procedures indicated below, and recommended according to
the information described on Table 2 in 5.5.3.3.1 and 5.5.3.3.2.
Method 1: transfer a sufficient amount of standard for a tared weighing bottle with a ground cap.
Weigh the bottle and put it in an oven under reduced pressure, tilting the cap over the bottle mouth to
ensure it remains open during the desiccation. Desiccate at 60 °C, under pressure of 0.67 kPa or less,
for three hours. With the process concluded, introduce dry air into the oven, submitting it to a
desiccating agent such as sulfuric acid or silica gel. Put the cap back on and put the weighing bottle
in a desiccator with a desiccating agent such as phosphorus pentoxide or silica gel. Let it cool down
at room temperature and weigh, calculating the percentage of loss of mass from the standard.
Method 2: proceed according to Method 1. However, use a tared weighing bottle with a cap with
capillary tube with 0.20 mm to 0.25 mm of internal diameter, and desiccate without removing the
cap.
Method 3: proceed according to Method 1. However, desiccate the sample at 110 °C, under pressure
of 0.67 kPa or less, for three hours.
Method 4: proceed according to Method 1. However, desiccate the sample at 40 °C, under pressure
of 0.67 kPa or less, for two hours.
Method 5: proceed according to Method 1. However, desiccate the sample at 100 °C, under pressure
of 0.67 kPa or less, for four hours.
Method 6: proceed according to Method 1. However, desiccate the sample at 40 °C, under pressure
of 0.67 kPa or less, for three hours.
Method 7: proceed according to Method 1. However, desiccate the sample at 25 °C, under pressure
of 0.67 kPa or less, for three hours.
PROCEDURE
Every material must be adequate to the intended use and be thoroughly cleaned, after each use, to
remove any vestige of antibiotic. The material must remain covered while it is not being used. All
glassware used in contact with the microorganism must be sterilized in oven, at temperature between
200 °C and 220 °C for two hours. When diluting the standard solution and sample, use volumetric
flasks, pipettes or carefully calibrated equipment items.
For each antibiotic listed on Table 1, check the culture medium (according to the list of culture
media), the amount of medium to be used in the base layer and in the inoculated layer, and the assay
microorganism. The volume of inoculum to be added to every 100 mL of culture medium must be
determined experimentally.
However, as an initial reference, the amount of inoculum to be added per 100 mL of medium is
suggested.
Prepare the base layer through addition of the appropriate number of molten agar on the Petri dishes,
which must be especially selected, have flat bottom, have dimensions of 20 x 100 mm and cap in
appropriate material. Distribute the agar evenly on the plates, which must be placed on a leveled
surface so that the middle layer has even depth. Put the cap from each plate beside it; if a non-porous
cap is used, leave it slightly opened to avoid buildup of condensed humidity from the hot agar layer.
After the agar hardening, cover the plates. To prepare the inoculated layer – surface, add the volume
of inoculum determined for the appropriate amount of culture medium that has been melted and
cooled down between 46 °C and 48 °C. Shake the flask, by rotation, to obtain an homogeneous
suspension, and add the indicated amount of medium inoculated on each Petri dish, with the non-
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
inoculated base layer. Spread the layer evenly, cover the plates and allow it to harden over a flat
surface.
After the medium hardening, put six stainless steel cylinders, with external diameter of (8 ± 0.1) mm,
internal diameter of (6 ± 0.1) mm and length of (10 ± 0,1) mm, over the inoculated agar surface, so
that they form a 60° angle with each other and a radius of 2.8 cm. Cylinders made of glass, porcelain
or aluminum and sterilized in the conditions already described can also be used. Instead of cylinders,
wells with 5 mm to 8 mm of diameter can be perforated, in the middle, with sterile perforator. Paper
discs, made with paper of appropriate quality or stainless-steel molds, can also be used. When paper
discs are used, they must be sterile. It is recommendable for obtaining satisfactory results that the
halos formed by the diffusion of drug in the medium have no less than 14 mm of diameter and a
maximum diameter so that there is no overlap between them.
The Table 2 indicates, for each antibiotic, the preparation of the standard working solution and the
standard curve, including:
a) conditions of desiccation, as described on item Desiccation of antibiotic substances (5.5.3.3);
b) initial solvent for dissolution of antibiotic, if necessary, and up to what concentration it is used;
c) solution for dilution until the working concentration, as described in Solutions;
d) concentration of the working solution, expressed in weight or International Units per mL of
solution;
e) validity period of the standard working solution under refrigeration;
f) solution used for dilution of the working solution, due to the preparation of the standard curve,
according to Solutions;
g) concentration ranges suggested, in weight or International Units per mL, within which the
adequate concentrations for the standard curve can be found.
Procedure for parallel lines design (3 x 3 or 2 x 2): use, on the assay, no less than six Petri dishes.
Arrange the standard and sample solutions, on each plate, with three concentrations for 3 x 3 assay
(low, medium and high) or two concentrations for 2 x 2 assay (low and high). The solutions must be
distributed in such a way that the solutions from the standard preparation and sample are alternated
in the inoculated layer (high and low concentration) to avoid overlapping of zones of inhibition.
Procedure for 5 x 1 design: for the standard curve, use a total of 12 plates, three for each of the
standard solutions (P1, P2, P4, P5), except for the medium concentration of the curve (P3), which is
included in all plates. In each set of three plates, use three cylinders for the medium concentration
(P3) and alternate three cylinders for low concentration (P1) and so forth with the other solutions from
the standard. This way, 36 zones of inhibition are obtained for the concentration (P3) and nine zones
of inhibition are obtained for each of the other four concentrations of the curve. For each sample, use
three plates, where three cylinders will be placed for the medium concentration of standard (P 3) and
three with the sample solution prepared on the same concentration of the standard (A3).
Apply 0.2 mL of the solutions in the cylinders or stainless-steel molds through pipette or another
calibrated instrument, if not specified in the individual monograph. When the well system is used, the
volume of liquid applied must be sufficient to fill them completely.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
After executing the adequate procedures for the design selected, incubate the plates at the indicated
temperature, which variation shall not exceed ± 0.5 °C, for a period of 16 to 18 hours. Then, measure
the diameter of the zones of inhibition, using an adequate device for measuring, such as the caliper,
or an optical projector with precision of 0.1 mm or less.
For some microorganisms, the procedure can be improved if the plates prepared remain at room
temperature for a period of 30 minutes to two hours before the incubation, a period when there is
diffusion of antibiotic to the medium
Table 1 (conclusion)
Volume (mL of medium Volume of Temperature of
Culture medium
Antibiotic Microorganism applied on the layers) Inoculum incubation
Base Surface Base Surface mL/100 mL (°C)
Cloxacillin Staphylococcus aureus (ATCC 6538p) 2 1 21 4 0.1 32 to 35
Colistin Bordetella bronchiseptica (ATCC 4617) 9 10 21 4 0.1 36 to 38
Dactinomycin Bacillus subtilis (ATCC 6633) 5 5 10 4 (1) 36 to 38
Dicloxacillin Staphylococcus aureus (ATCC 6538p) 2 1 21 4 0.1 32 to 35
Dihydrostreptomycin Bacillus subtilis (ATCC 6633) 5 5 21 4 (1) 36 to 38
Erythromycin Kocuria rhizophila (ATCC 9341) 11 11 21 4 1.5 32 to 35
Streptomycin Bacillus subtilis (ATCC 6633) 5 5 21 4 (1) 36 to 38
Phenethicillin Kocuria rhizophila (ATCC 9341) 11 11 21 4 0.5 32 to 35
Phenoxymethylpenicillin Staphylococcus aureus (ATCC 6538p) 2 1 21 4 1.0 32 to 35
Gentamicin Staphylococcus epidermidis (ATCC 12228) 11 11 21 4 0.03 36 to 38
Griseofulvin Microsporum gypseum (ATCC 14683) 20 21 6 4 (1) 29 to 31 for 48 hours
Mitomycin Bacillus subtilis (ATCC 6633) 8 8 10 4 0.5 36 to 38
Neomycin Staphylococcus aureus (ATCC 6538p) 11 11 21 4 1.0 32 to 35
Neomycin Staphylococcus epidermidis (ATCC 12228) 11 11 21 4 1.0 36 to 38
Nystatin Saccharomyces kudriavzevii (ATCC 2601) ̶ 19 ̶ 8 1.0 29 to 31
Novobiocin Staphylococcus epidermidis (ATCC 12228) 2 1 21 4 4.0 34 to 36
Ofloxacin Kocuria rhizophila (ATCC 9341) 1 11 20 5 0.5 30 to 35
Oxacillin Staphylococcus aureus (ATCC 6538p) 2 1 21 4 0.3 32 to 35
Paromomycin Staphylococcus epidermidis (ATCC 12228) 11 11 21 4 2.0 36 to 38
Polymyxin B Bordetella bronchiseptica (ATCC 4617) 9 10 21 4 0.1 36 to 38
Rifampicin Bacillus subtilis (ATCC 6633) 2 2 21 4 0.1 29 to 31
Rifampicin Staphylococcus aureus (ATCC 6538p) 2 2 21 4 0.1 36 to 38
Sisomicin Staphylococcus epidermidis (ATCC 12228) 11 11 21 4 0.03 36 to 38
Tetracycline Staphylococcus epidermidis (ATCC 12228) 1 1 20 5 2.0 33 to 37
Vancomycin Bacillus subtilis (ATCC 6633) 8 8 10 4 (1) 36 to 38
(1) Determine the amount of inoculum, on the assay, through diffusion on plates.
Table 2 (conclusion)
a. Condition of d. Concentration e. Validity period of f. Solution for g. Concentration
c. Solution for
Antibiotic desiccation b. Initial solvent of working the solution under dilution range
dilution (5.5.3.3)
(5.5.3.3) solution (/mL) refrigeration (5.5.3.3) (/mL)
10,000 µg per mL
Chloramphenicol 8 1 1 mg 30 days 1 20 to 80 µg
in ethyl alcohol
Cloxacillin 8 ̶ 1 1 mg 7 days 1 2 to 8 µg
10,000 µg per mL
Colistin 1 4 1 mg 14 days 4 0.5 to 2 µg
in ethyl alcohol
10,000 µg per mL
Dactinomycin 1 2 1 mg 90 days 2 0.5 to 2 µg
in methyl alcohol
Dicloxacillin 8 ̶ 1 1 mg 7 days 1 2.5 to 10 µg
Dihydrostreptomycin 5 ̶ 2 1 mg 30 days 2 0.5 to 2 µg
10,000 µg per mL
Erytrhomycin5 1 2 1 mg 14 days 2 0.5 to 2 µg
in methyl alcohol
Streptomycin 1 ̶ 2 1 mg 30 days 2 0.5 to 2 µg
Phenethicillin 8 ̶ Sterile water 1000 IU 7 days 2 0.05 to 0.2 IU
Phenoxymethylpenicilli
8 ̶ 1 100 IU 4 days 1 0.2 to 2 IU
n
Gentamicin 3 ̶ 2 1 mg 30 days 2 0.5 to 2 µg
Dimethylformamid
Griseofulvin 8 ̶ 1 mg4 90 days 2 2 to 10 µg
e
Mitomycin 8 ̶ 1 1 mg 14 days 1 0.5 to 2 µg
5 to 20 µg
Neomycin 1 ̶ 2 1 mg 14 days 2
(S. aureus)
0.5 to 2 μg
Neomycin 1 ̶ 2 1 mg 14 days 2
(S. epidermidis)
Dimethylformamid
Nystatin 4 ̶ 1000 IU2 Use on the same day 4 10 to 40 IU7
e
Novobiocin 5 10,000 µg per mL 2 1 mg 5 days 4 0.2 to 1 µg
in ethyl alcohol
On the Table 2, presented below, there is an indication, for each antibiotic, of the preparation of the
standard working solution and the standard curve, including:
a) conditions of desiccation, as described on item Desiccation of antibiotic substances (5.5.3.3);
b) initial solvent for dissolution of antibiotic, if necessary, and up to what concentration it is used;
c) solution for dilution of antibiotic until the working concentration, according to Solutions;
d) concentration of working solution, expressed in weight or International Units per mL of solution;
e) validity period of the standard working solution under refrigeration;
f) solution used for dilution of the working solution, for the preparation of the standard curve,
according to Solutions;
g) concentration range, in weight or International Units per mL, within which the adequate
concentrations for the standard curve can be found.
Use for each antibiotic the microorganism and nutritive broth listed on Table 1. Determine
experimentally the volume of inoculum to be added to 100 mL of broth from the amount suggested
as initial reference. The inoculated medium must be prepared and used immediately.
Procedure for parallel lines design (3 x 3 or 2 x 2): distribute, in identical tubes, an equal volume of
each of the standard and sample solutions. Add to each tube an equal volume of inoculated nutrient
broth, for example, 1 mL of solution with antibiotic and 9 mL of medium (0.1 mL of solution for
gramicidin and tyrothricin). No less than eighteen tubes are used for parallel lines 3 x 3 assay and
twelve tubes for parallel lines 2 x 2 assay. The number of replicas per concentration in each assay
must be sufficient to ensure the statistical precision specified on the monograph, but no less than three
tubes must be executed for each concentration of standard and sample. It may be necessary to conduct
the assay with a higher number of doses of standard and sample, or repeat it and match the results to
obtain the precision required. The doses used must be in geometric progression.
Procedure for 5 x 1 curve design: for the 5 x 1 design, prepare dilutions that represent five
concentrations of the standard (P1, P2, P3, P4 and P5) and one concentration of sample (A3). The
sample solution must correspond to the same dilution of standard that corresponds to the average
concentration of the curve (P3). Use no less than three tubes for every concentration of the standard
and sample. This way, no less than18 tubes are necessary on the assay.
After executing the adequate procedures for the design selected, inoculate the culture medium
recommended with a known amount of suspension of the antibiotic-sensitive microorganism, so that,
after incubation of approximately four hours, the bacterial turbidity in the medium is easy to measure
and maintains correlation between the dose and the response of the substance being analyzed.
The Table 1 describes the antibiotics to be analyzed by the turbidimetric method with description of
the microorganism, culture medium, volume of standardized inoculum suggested as initial reference,
and temperature of incubation for each case.
Incubate in water bath for three to four hours, taking the precaution of ensuring adequate and constant
temperature for all tubes. The adequate time must be checked by observation of growth in the tube
Brazilian Health Regulatory Agency - Anvisa
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
with the average concentration (P3) used on the assay. After the incubation period, interrupt the
multiplication of microorganisms by adding 0.5 mL of formaldehyde solution 12%, to each tube.
Determine the absorbance for each tube in spectrophotometer, on the wavelength of 530 nm.
Standardize the device in absorbance through the blank with the same amount of nutrient broth and
formaldehyde, 12%.
In routine assays, when the system linearity is proven by an adequate number of experiments
employing the three-point assay (3 x 3), the two-point assay (2 x 2) can be used. The 5 x 1 design,
adopted by other pharmacopoeias of current international use, will also be accepted. However, in case
of controversy or litigation, the three-point assay must be applied.
Calculation of potency
From the results, calculate the potency of the sample and its confidence limits, through standard
statistical method described on Statistical procedures applicable to biological assays – indirect
quantitative assays.
The precision of an assay is verified by the confidence interval, which ensures that the true potency
is within the limits specified. In the absence of CI from the product monograph, it is recommendable
to have upper and lower confidence limits of 5.0% or less, in relation to the potency calculated, with
limit values of up to 10% being accepted.
Volume of Temperature of
Nutrient
Antibiotic Microorganism inoculum incubation
broth
mL/100 mL (°C)
(ATCC 10536)
Klebsiella pneumoniae
Streptomycin 3 0.1 37
(ATCC 10031)
Enterococcus hirae
Gramicidin 3 1.0 37
(ATCC 10541)
Staphylococcus aureus
Lincomycin 3 0.1 37
(ATCC 6538p)
Staphylococcus aureus
Minocycline 3 0.2 37
(ATCC 6538p)
Staphylococcus aureus
Oxytetracycline 3 0.1 37
(ATCC 6538p)
Staphylococcus aureus
Rolitetracycline 3 0.1 37
(ATCC 6538p)
Staphylococcus aureus
Tetracycline 3 0.1 37
(ATCC 6538p)
Enterococcus hirae
Tyrothricin 3 1.0 37
(ATCC 10541)
Staphylococcus aureus
Tobramycin 3 0.15 37
(ATCC 6538p)
Table 2 – Preparation of the standard solution and standard curve – Turbidimetric method.
g.
a. Condition of c. Solution for d. Concentration e. Validity period of f. Solution for
Concentration
Antibiotic desiccation b. Initial solvent dilution of working the solution under dilution
range
(5.5.3.3) (5.5.3.3) solution (/mL) refrigeration (5.5.3.3)
(/mL)
Amikacin 8 - Sterile water 1 mg 14 days Sterile water 6 to 14 µg
Kanamycin 8 - Sterile water 1 mg 30 days Sterile water 6 to 14 µg
Dimethyl Use on the same
Candimycin1 6 - 1 mg Sterile water 0.02 to 0.14 µg3
sulfoxide day
Capreomycin 5 - Sterile water 1 mg 7 days Sterile water 60 to 180 µg
Cycloserine 1 - Sterile water 1 mg 30 days Sterile water 20 to 80 µg
10,000 µg per mL in 1
Chloramphenicol 8 1 mg 30 days 1 1 to 4 µg
ethyl alcohol
Chlortetracycline 8 - HCl 0.01 M 1 mg 4 days Sterile water 0.03 to 0.09 µg
Demeclocycline 1 - HCl 0.1 M 1 mg 4 days Sterile water 0.06 to 0.14 µg
Dihydrostreptomycin 5 - Sterile water 1 mg 30 days Sterile water 20 to 60 µg
Doxycycline 8 - HCl 0.1 M 1 mg 5 days Sterile water 0.06 to 0.14 µg
Spectinomycin 8 - Sterile water 1 mg 30 days Sterile water 20 to 60 µg
Streptomycin 1 - Sterile water 1 mg 30 days Sterile water 20 to 60 µg
Ethyl alcohol
Gramicidin 1 - 1 mg 30 days Ethyl alcohol 95% 0.02 to 0.08 µg
95%
Lincomycin 8 - Sterile water 1 mg 30 days Sterile water 0.3 to 0.8 µg
Minocycline 8 - HCl 0.1 M 1 mg 2 days Sterile water 0.06 to 0.12 µg
Oxytetracycline 8 - HCl 0.1 M 1 mg 4 days Sterile water 0.16 to 0.32 µg
Rolitetracycline 1 - Sterile water 1 mg 1 day Sterile water 0.16 to 0.32 µg
Tetracycline 8 - HCl 0.1 M 1 mg 1 day Sterile water 0.16 to 0.32 µg
Ethyl alcohol
Tyrothricin2 1 - 1 mg 30 days Ethyl alcohol 95% 0.02 to 0.08 µg
95%
Tobramycin 8 - Sterile water 1 mg 14 days Sterile water 1 to 4 µg
1
In the candicydin assay, use sterile equipment in all steps.
2
For the tyrothricin assay, use the standard working solution and the dose-response curve of gramicidin.
3
Prepare, simultaneously, the standard and sample solutions.
The amount of preservative used in a formulation must be the minimum necessary for protecting the
product without harming the patient or the consumer.
The antimicrobial effectiveness, whether inherent to the product or due to the addition of
preservatives, needs to be demonstrated for topical multiple-dose products, oral products, ophthalmic
products, otologic products, nasal products, fluids for dialysis, irrigation, etc.
The test and the criteria established apply to the product how it is found in the market.
MICROORGANISMS USED
The microorganisms used in the test must have no more than five passages counted from the original
ATCC culture. A passage is defined as the transfer of a stablished culture to a sterile culture medium.
In case of cultures maintained by freezing techniques, each cycle of freezing, thawing and reactivation
is considered a passage. Lyophilized cultures received from ATCC must be reconstituted according
to instructions provided with the material.
Recover the material in a liquid or solid culture medium. The conditions for culture preparation are
registered on Table 1.
If the microorganism is recovered in liquid culture medium, after incubation, centrifuge and discard
the supernatant. Suspend the sediment with a dilution 1/20 of the sterile maintenance culture medium
and add an equal volume of sterile glycerol solution 20% v/v in water.
If the microorganism is recovered in a solid culture medium, transfer the surface growth to the sterile
liquid maintenance culture medium, added with sterile 10% glycerol. The test and the criteria
established apply to the product how it is found in the market.
In both cases, dispense small aliquots of the suspension in sterile cryogenic tubes, appropriate for
freezing microorganisms.
Store the cryogenic tubes in liquid nitrogen or ultra-freezer (no more than -50 °C). This stock culture
can be used to inoculate a series of working culture.
All culture media used in the test must be tested for their capacity of growth.
PREPARATION OF INOCULUM
From the stock culture, inoculate the surface of the solid culture medium specified on Table 1.
To collect the growth of bacteria and yeasts, use sterile saline solution. Collect the suspension
obtained in an appropriate sterile tube or vial and add a sufficient amount of sterile saline solution to
obtain a concentration of 1 x 108 CFU/mL.
To collect the growth of A. niger, use sterile saline solution with 0.05% of polysorbate 80. Collect the
suspension obtained in an appropriate sterile tube or vial and add a sufficient amount of sterile saline
solution to obtain a concentration of 1 x 108 CFU/mL.
Alternatively, the stock culture can be inoculated in liquid medium (Table 1), incubated and then
centrifuged. Discard the supernatant and suspend the sediment with sufficient amount of sterile saline
solution to obtain a concentration of 1 x 108 CFU/mL.
Refrigerate the suspensions if you do not use them in a period of two hours.
Determine the number of CFU/mL of each suspension by turbidimetry or counting on plate, checking
the conditions of time and temperature of incubation and the incubation time for microbial recovery
described on Table 1, with the purpose of confirming the count in initial CFU. These values will be
used to calibrate the size of inoculum to be used in the contaminations of the product being tested.
The suspension of bacteria and yeasts must be used in 24 hours. The suspension of molds can be used
in up to seven days if maintained under refrigeration.
PROCEDURE
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
When the type of package allows the introduction of suspension of microorganisms and when its
content is sufficient to execute all steps, conduct the test in five original packages of the product to
be tested. Otherwise, transfer the content from one or more original packages to a vial with cap,
previously sterilized and of adequate size to contain the necessary amount of sample for executing all
steps of the test.
Inoculate each original package or vial with sterile cap with each one of the microorganisms required.
The concentration of the inoculum used must be sufficient to obtain a final concentration on the
product between 1 x 105 and 1 x 106 CFU/g or mL – applicable to the categories 1, 2 and 3 (see Table
2 – column “Type of Product”).
For category 4, the concentration of inoculum must be sufficient to obtain a final concentration on
the product between 1 x 103 and 1 x 104 CFU/g or mL.
The volume of inoculum to be introduced must be between 0.5% and 1.0% in relation to the total
volume (liquid sample) or weight (solid or semisolid sample) of the product.
Incubate the inoculated samples in oven with temperature between (22.5 ± 2.5) °C.
Sample each package or vial with inoculated sample in intervals of 7, 14 and 28 days.
Determine by the plating method the number of Colony-Forming Unit (CFU) of each sample, in the
initial time and in each time interval specified.
A neutralizing agent specific for the preservative(s) present in the product formulation, determined
in the validation study, must be incorporated to the counting plates or in the dilution of the sample
prepared for plating.
Calculate the concentration of each microorganism (CFU/mL) present in the sample, compare with
the counting at the initial time, and express the change in terms of logarithmic reductions.
For the purpose with the test, the products have been separated in four categories according to Table
2, which lists the criteria established for antimicrobial effectiveness.
Note: the “non-increase” in the number of CFU inoculated is defined as no more than 0.5 log10 of
units bigger than the value previously obtained.
Email:enquiries@ncimb.com
Sampling is an important step in the water quality assessment, since the sample taken for analysis
must precisely reflect the performance of the production and distribution system and the quality of
the water used. An inadequate sampling may lead to an incorrect assessment, generating unnecessary
interventions in the purification system, or compromising the accuracy of the water quality status
through an imprecise result.
Considering the peculiarities of each system, the water samples must be taken from the place of their
generation to the points of use, since the results obtained in the generation may not reflect the quality
of water in the points of use.
The collection of samples in the points of use must be conducted employing practices identical to the
ones used routinely in the use of water at that point, mimicking the system operation (valve purge,
use of hoses, sanitization of the point, etc.).
The initial sampling plan is usually developed for a program of validation of the system of production
of water for pharmaceutical use, in order to characterize its capacity of purification, distribution and
supply of water. The sampling plan has short duration (for example, two to four weeks) and
determines a high frequency of collection of samples, to generate a significant volume of data that
offers an initial assessment of the system performance, to guide the decisions about the use of the
water produced.
The initial sampling plan is reassessed when the system is placed in operation, usually to look for a
reduction in the amount of data being generated without compromising the capacity to identify
abnormal operations/events, especially during the initial phase of the water system life cycle. In the
absence of such deviations of quality during the initial sampling period, the frequency of sampling
can be reduced to ensure that, in a slightly longer period (for example, for no less than another two to
four weeks), there are no adverse quality trends. During this period of time for validation of the second
sampling plan, the use of water in routine may be considered a risk. After concluding the assessment,
if successful, the monitoring may eventually be reduced again for the sampling plan to be adopted as
routine.
Periodically, it is necessary to review the system operation and monitoring to assess the seasonal
variability of the water source, the effectiveness of sanitization, and the routine maintenance events.
This review must be conducted during the entire life cycle of the water production system, usually
every year, to make evident the trend of quality deviations from long-term data.
The sampling plan adopted in the routine must also be reassessed periodically, based on data
available, to reassess the frequency and adequate sampling sites. This step offers an opportunity to
improve the data assessment and reduce the work loads based on what the data indicate about the
process and quality control. The sampling plan adopted as routine must have a rational base for the
frequency and sampling sites established, in order to justify how the resulting data will be used to
characterize the general system operation and for clearing water for use.
The samples must be collected in sterile borosilicate glass vessels or in sterile plastic bags adequate
for microbiological use. The volume of sample must be sufficient to conduct all analysis necessary.
The amount of sample added to the vessels must allow homogenization before conducting the assays,
being suggested a space of no less than 2.5 cm above the water surface (headspace).
Disinfectant agents, such as chlorine or other halogenated compounds, when present in water
samples, must be neutralized before conducting tests, to ensure adequate recovery of microorganisms
that are possibly present. A neutralizing agent commonly used is the sodium thiosulfate solution
(0.1 mL of a solution 3% neutralizes above 5 mg/L of residual chlorine in a 120 mL sample).
STORAGE CONDITIONS
The tests must be conducted in the sample up to two hours after the collection and, if it is not possible
to conduct the test within this interval, the sample must be kept at refrigeration temperature in the
range of 2 °C to 8 °C for no more than 12 hours, to maintain the microbiological characteristics until
the analysis. In situations when not even this is possible (such as when laboratories hired out of the
site are used), the assay of these refrigerated samples must be conducted within 24 hours after the
collection.
CULTURE MEDIA
Endo C agar
Peptic hydrolysate from animal tissue 10.0 g
Lactose 10.0 g
Dibasic potassium phosphate 3.5 g
Sodium sulfite 2.5 g
Basic fuchsine 0.5 g
Agar 15.0 g
Purified water q.s.p. 1000 mL
pH 7.4 + 0.2. Sterilize in autoclave using validated cycle.
M-Pa-C Agar
L-lysine 5.0 g
Sodium chloride 5.0 g
MacConkey Agar
Pancreatic gelatin hydrolysate 17.0 g
Pancreatic casein hydrolysate 1.5 g
Peptic hydrolysate from animal tissue 1.5 g
Lactose 10.0 g
Bile salts 1.5 g
Sodium chloride 5.0 g
Neutral red 0.03 g
Crystal violet 0.001 g
Agar 13.5 g
Purified water q.s.p. 1000 mL
pH 7.1 + 0.2. Sterilize in autoclave using validated cycle.
m-HPC Agar
Peptone 20.0 g
Gelatin 25.0 g
Glycerol 10.0 mL
Agar 15.0 g
Purified water q.s.p. 1000 mL
Homogenize the reagents, except glycerol. Adjust the pH to 7.1 ± 0.2, heat to dissolve and transfer
the glycerol. Sterilize in autoclave using validated cycle.
R2A agar
Peptone (casein or animal tissue) 0.5 g
Casamino Acid 0.5 g
Yeast Extract 0.5 g
EC or EC-MUG broth
Tryptose or trypticase 20.0 g
Lactose 5.0 g
Mixture of bile salts 1.5 g
Dipotassium hydrogen phosphate 4.0 g
Potassium dihydrogen phosphate 1.5 g
Sodium chloride 5.0 g
4-methyl-umbelliferyl-β-D-glucoronide (MUG) 0.05 g
Purified water q.s.p. 1000 mL
pH 6.9 ± 0.2. Before the sterilization, dispense in tubes that do not presence in high UV light
wavelengths (366 nm). The Durham tube is not necessary. Sterilize in autoclave using validated cycle.
The methods presented are optional and may or may not be ideal for recovery of microorganisms,
including the undesirable ones. The selection must be made through experiments, determining which
are the adequate methods for monitoring its process, and also for the recovery of specific
microorganisms that can be found in water purification systems and may be undesirable for the
products to be handled.
There are two categories of culture media for count of the total number of heterotrophic bacteria: the
ones with high concentration of nutrients, such as the plate count agar (PCA), soybean-casein digest
agar, and m-HPC agar, being adequate for general isolation and count of heterotrophic or copiotrophic
bacteria, and the ones with low concentration of nutrients, such as R2A agar, which is indicated for
recovery of oligotrophic bacteria.
The temperature and the incubation time are critical aspects for microbiological tests of water, due to
the types of microorganisms found in the water systems. Incubations at low temperatures (for
example, 20 °C to 25 °C or 25 °C to 30 °C) for longer periods, no less than four days, may lead to
higher recoveries of microorganisms than classic temperatures. Media with low amount of nutrients
require longer incubation periods (no less than five days), because such media promote a slower
growth. Even the ones with high concentration of nutrients may sometimes result in high microbial
recovery for long periods of incubation and lower temperatures.
The decision about the type of culture medium and the incubation temperature to test a water
purification system must be based on comparative cultivation studies using a native microbiome from
the water purification system being analyzed.
PROCEDURE
Plate depth method: add 1 mL of the sample to a Petri dish and pour 15 mL to 20 mL of culture
medium maintained at 45 °C to 50 °C, according to Table 1. Conduct the test at least on duplicate.
Membrane filtration method: use filtration equipment that allows transferring the membrane to
culture media. Use a sterile membrane with 47 mm of diameter and 0.45 µm of porosity, washing the
membrane, after the sample filtration, with three portions of 20 mL to 30 mL of sterile purified water.
The volume to be filtered may vary according to the sample, obeying a maximum volume that
provides 20 CFU to 200 CFU per membrane.
PROCEDURE
Shake the sample vigorously. Use five portions of 20 mL, 10 portions of 10 mL or a single sample of
100 mL. Mix the portions of sample in the medium slightly stirring. Incubate at (35 ± 0.5) °C. After
(24 ± 2) hours, shake each tube slightly and observe for presence of growth or formation of gas; if no
gas is evident, re-incubate the tubes and reexamine at the end of (48 ± 3) hours. Register the presence
or absence of growth and gas. Turbidity or production of gas in the tubes within (48 ±3) hours
comprises a positive presumptive reaction. In this case, carry on with the confirmatory phase.
Confirmatory phase – Use Brilliant green bile lactose broth. Make sure that the inverted Durham
tubes are free of bubbles. Slightly shake the positive Lauryl tryptose broth fermentation tubes and
inoculate one or more loops of culture in Brilliant green bile lactose broth. Incubate the Brilliant green
bile lactose broth tubes at (35 ± 0.5) °C. The growth and formation of any amount of gas within (48 ±
3) hours comprises a positive confirmatory phase, indicating the presence of total coliforms.
To estimate the density of coliforms, calculate the Most Probable Number (MPN) from the number
of positive tubes of Brilliant green bile lactose broth (Tables 3 and 4).
Table 3 – MPN index and confidence limits of 95% for all combinations of positive and negative results when
five portions of 20 mL of sample are used.
Table 4 – MPN index and confidence limits of 95% for all combinations of positive and negative results when
10 portions of 10 mL of sample are used.
Number of tubes with positive Confidence limit of 95% (exact)
result MPN index/100 mL
(10 mL of sample each) Low High
0 < 1.1 - 3.4
1 1.1 0.051 5.9
2 2.2 0.37 8.2
3 3.6 0.91 9.7
4 5.1 1.6 13
5 6.9 2.5 15
6 9.2 3.3 19
7 12 4.8 24
8 16 5.8 34
9 23 8.1 53
10 >23 13 -
Complete phase: – Slightly shake the positive Brilliant green bile lactose broth fermentation tubes
and inoculate one or more loops of culture in EC or EC-MUG broth. Alternatively, the inoculation in
EC or EC-MUG broth may be done from the culture in Lauryl tryptose broth simultaneously to the
inoculation in Brilliant green bile lactose broth in the confirmatory phase. Incubate the tubes of EC
or EC-MUG at temperature of (44 ± 0.2) °C for (24 ± 2) hours.
The observation of growth and the production of gas in the EC or EC-MUG tubes indicate the
presence of fecal coliforms or E. coli, respectively. In parallel, positive cultures from Brilliant green
bile lactose broth with negative results on EC or EC-MUG broths indicate the presence of non-fecal
coliforms.
Confirmatory tests using selective and differential media and biochemical tests for identification of
species may be conducted when necessary.
Membrane filtration method: use filtration equipment that allows transferring the membrane to
culture media. Use a sterile membrane with 47 mm of diameter and 0.45 µm of porosity, washing the
membrane, after the sample filtration, with three portions of 20 mL to 30 mL of sterile purified water.
The volume to be filtered may vary according to the sample, obeying a maximum volume that
provides 20 CFU to 200 CFU per membrane. For research of coliforms, the membrane must be
incubated in specific medium (for example, MacConkey, endo C, eosin methylene blue, etc.), at the
temperatures established for studies on total and fecal coliforms for 24 hours.
Chromogenic method: culture media that have in their formulation specific enzyme substrates allow
significant improvements in the recovery of microorganisms and in their identification.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition MG5.5.3-02
In case of research of total coliforms and E. coli, there are alternative methods correlated to the
traditional membrane filtration and multiple tube methods. There are tests based on using a specific
substrate, which allow the simultaneous research on fecal coliforms and E. coli in a shorter period of
time. For example, tests based on the activity of β-galactosidase over the ONPG (O-nitrophenyl-β-
D-galactopyranoside) substrate and of β-D-glucuronidase over the MUG (4-methylumbelliferyl-β-D-
glucoronide) substrate. The test is based on the addition of 100 mL of sample to the substrates and
incubation at 35 °C to 37 °C for 24 hours. The activity of total coliforms over the ONPG substrate
produces a yellow coloration, indicating their presence. The presence of E. coli can be confirmed by
fluorescence under UV light, due to their activity over the MUG substrate.
PROCEDURE
Membrane filtration method: filter 200 mL of sample through sterile filtration membrane. Put each
membrane on the M-Pa-C agar plate so that there is no room between the membrane and the agar
surface. Invert the plates and incubate at (41.5 ± 0.5) °C for 72 hours. Typically, the P. aeruginosa
colonies have 0.8 mm to 2.2 mm of diameter and are apparently flat, with clear edge and brownish to
dark green core. Count typical colonies, preferably from the filter with 20 to 80 colonies. Confirm the
presence of P. aeruginosa through adequate biochemical tests. Other methods and culture media can
be used, provided that duly validated.
The results from immunochemical methods depend on the conditions of the experience, the nature
and the quality of the reagents used. It is essential to measure the components of an immunological
assay and use international preparations of reference for immunoassay whenever available. The
reagents necessary to many of the immunochemical methods are available in the market in the form
of kits that include reagents (especially the antigen or antibody) and the materials targeted at in vitro
assessment of a certain substance, as well as the necessary instructions for their correct use. The kits
must be used according to instructions from the manufacturer, and it is important to make sure they
are adequate to the sample analysis, especially concerning selectiveness and sensitivity. The
requisites related to kits for immunoassay are provided by the World Health Organization.
The techniques that use labeled substances must use appropriate labels, such as enzymes and
radioisotopes. When the label is a radioisotope, we call the technique radioimmunoassay. All
techniques conducted with radioactive substances must be in compliance with the national and
international legislation for protection against the risk from radiations.
precipitation zone, originated from the external reagent, is directly proportional to the concentration
of antigen applied and inversely proportional to the concentration of antibodies in gel.
Double diffusion methods. The concentration gradients are established for two reagents. Both the
antigen and the antibody diffuse from separate places in a gel that is initially neutral under the
immunological standpoint. The double immunodiffusion methods are used to compare, qualitatively,
several antigens in relation to an appropriate antibody, or vice-versa. The comparison is based on the
presence or absence of interaction between the precipitation standards. It is possible to distinguish
reactions of identity, non-identity or partial identity between antigens and antibodies.
In translucent gels, such as agar or agarose, the precipitation line becomes clearly visible in the gel,
provided that the concentration of each of the reagents is adequate.
VALIDATION OF METHOD
b) the method is not influenced by the assay matrix, that is, all components of the sample being
analyzed, or its excipients, that may vary from one sample to the other. They may include high
concentrations of other proteins, salts, preservatives in high concentrations, or have a proteolytic
contamination activity;
c) the limit of quantification is lower than the criteria for acceptance indicated in the individual
monograph;
d) the accuracy of assay is such that the variation of results corresponds to the requirements
established in the individual monograph;
e) absence of systematic errors when conducting the assay.
For these criteria to be checked, the validation includes the following elements:
a) the assay must be conducted at least in triplicate;
b) the assay must include no less than three different dilutions of standard and three different
dilutions of sample with supposed activity similar to the one from the standard preparation;
c) the samples must be distributed randomly;
d) if the sample is present in serum, or if it is mixed with other constituents, the standard must be
prepared in the same way;
e) the assay must include a measure of non-specific bond of the labeled reagent;
f) for radioimmunoassays with shift: the maximum bond (zero shift) must be determined and the
dilutions must cover the full range of responses to the closest values from the non-specific bond to
the maximum bond, preferably both for the sample and for the standard.
STATISTICAL CALCULATION
For analysis of results, the response curves from sample and standard can be analyzed by the statistical
procedures applicable to biological assays. The significant non-parallelism indicates that the antigen
or antibody distinguishes the sample from standard and implies in invalidation of result. On
immunoassays with shift, the values from non-specific bond and maximum shift at a high
concentration of sample or standard must not be significantly different. The differences may reflect
effects due to the matrix, whether by inhibition of bond or degradation of label.
The determination of tensile strength of surgical sutures must be made in an environment with
constant humidity and temperature. The relative air humidity must be between 60% and 80% and the
temperature, between 20 °C and 25 °C.
EQUIPMENT
When determining the tensile strength of surgical sutures, the equipment must have an electric motor
that applies to the suture being analyzed a constant load rate per time unit.
Specifications: the clamps must be of roll type with flat surfaces for fastening the sutures. The roll
diameter must be of 1.8 cm to 1.9 cm and the flat surfaces must have no less than 2.5 cm of length.
The distance between clamps must be 1.25 cm. The load carriage friction must allow the recording
pen to slide up to 2.5% of the registration capacity when there is no sample. The plan inclination
speed must be adjusted so that 20 seconds are necessary from the beginning of the test for the
maximum slope of 30 degrees to be achieved.
PROCEDURE
Determine the tensile strength of surgical sutures with the same preliminary precautions required for
the diameter determination test. Adjust the weight of the carriage so that, at the moment the rupture
occurs, the position of the recording pen is between 20% and 80% of the registration capacity.
Direct traction: insert the suture in the equipment by fastening one of the ends and passing the free
end through the other clamp. Apply on it a tension equivalent to 25% of the minimum strength
required for the suture being tested and tighten the clamp. Adjust the recording pen on the point zero
of the chart and turn the equipment on; record the reading and assess the strength. Discard the
determination when the suture ruptures, near the clamps.
Traction on knot: determine the tensile strength over surgical knot by making on the suture being
tested a surgeon’s knot (Figure 1) over a segment of a flexible rubber tube with 5 cm of length,
6.5 mm of internal diameter, and 8.1 mm of external diameter. Place the suture on the equipment so
that the knot is positioned equidistantly from the clamps. Adjust the recording pen on the point zero
of the chart and turn the equipment on; record the reading and assess the strength. Discard the
determination when the suture ruptures, near the clamps.
f) put the right side end over the left side end, forming a second loop;
g) close the knot.
Results: The results must comply with what is described on the respective monographs.
APPARATUS
The gauge used to determine the diameter of sutures is of “dead weight” type, mechanical or
electronic, and is equipped with a direct, digital or printed reading output dial. The scale resolution is
of no less than 0.002 mm and the presser foot must have approximately (12.70 ± 0.02) mm of
diameter. The presser foot and the moving parts connected to it must have total load of (210 ± 3) g to
the sample. For sutures of surgical number 9-0 and smaller, remove the additional weight from the
presser so that the total weight on the sample does not exceed 60 g. The presser foot and the equipment
base must present parallelism and flatness of 0.005 mm.
PROCEDURE
The diameter of surgical sutures of natural origin, packaged without preservative liquid, is determined
after they remain for no less than four hours in atmosphere with temperature and humidity previously
specified. The sutures packaged with preservative liquid are submitted to test immediately after they
are removed from the liquid, without prior drying.
Multifilament sutures
To determine the diameter of multifilament surgical sutures, the measurements must be made keeping
them tensioned with the help of a roller system fastened to a table, according to Figure 1, and
proceeding as detailed below:
a) fasten one of the suture ends through a fastening clamp;
b) on the other free end, put a weight with a mass according to Table 1. Note: It is necessary to be
careful to not twist the suture;
c) position the suture on the gauge so that it passes through the center of the circular base and, with
the help of a lever, lower the moving rod foot slowly until the entire load is applied;
d) measure the suture diameter on three points, approximately at 1/4, 1/2 and 3/4 of its total length;
e) in case of braided sutures with diameters larger than the surgical number 3-0, make two
perpendicular measurements in each point.
Gauge
Guide roller
Device table base
Weight
Figure 1 – Model of table suggested for measuring the diameter of multifilament sutures.
Monofilament sutures
Result: The average of the measurements made in the sutures must be between the limits established
on the respective monographs. Individual values must be comprised between the averages of limits
for surgical numbers, immediately inferior and posterior to the one analyzed.
APPARATUS
Use an universal traction machine equipped with electric motor that applies a constant load rate per
time unit. The load cell used must be compatible with the necessary traction force for checking.
PROCEDURE
Fasten the needle to one of the equipment clamps so that the threaded part is free and aligned with
the direction where the force will be applied by the moving clamp. Measure the strength required to
unthread the suture from the needle.
Note: the assessment of resistance to threading must consider simultaneously the individual limits
for threads and the limits for the average of five threads from the lot analyzed. If one of the individual
limit results, and no more than one, does not meet the minimum limits for individual values, repeat
the assay with another ten threads. The assay requisite will be met if none of the 10 samples is below
the limits described.
PROCEDURE
Use a basket that weighs no more than 3 g, made of copper wire with approximately 0.4 mm of
diameter, in the shape of a cylinder with approximately 5 cm of diameter and 8 cm of depth, with
spaces of approximately 2 cm between wires. Transfer portions of hydrophile cotton with, exactly,
approximately (1 ± 0.05) g, from five different parts of the package, through pulls, not cuts of the
sample. Place the matched portions in the basket and weigh. Hold the basket by its side approximately
12 mm from the water surface at (25 ± 1) °C and let it drop in the water. Determine, preferably by
using a timer, the time in seconds required for complete submersion.
Remove the basket from the wire, let it drain for 10 seconds in the same horizontal position, then
place it immediately in a vessel tared and covered, and weigh. Calculate the mass of water absorbed
from the mass of the test basket and the mass of hydrophile cotton.
This procedure applies to the Suter-Webb cotton fiber duplex sorter device. With changes in the
procedure, it may be applied to two Baer sorters arranged sequentially, or to a Johannsen or another
similar device.
APPARATUS
The sorter consists of two banks with combs rigidly assembled side by side over a common base.
Each bank of combs consists of no less than 12 individual combs spaced 3.2 mm apart, one behind
the other, and fitted so that, as they are approached during the fractioning process and no longer
necessary, they can be released to fall below the work plan. Each comb has a single series of teeth
precisely aligned and very sharp, with 12 mm of length, comprised of needles with 0.38 mm of
diameter. The teeth are spaced 62 mm to 25 mm apart in an extension of approximately 50 mm.
The accessories consists of fiber sorter forceps, fiber depressing grid, flat fiber depressor plate, and
velvet-covered plates. The sorter forceps consists of two brass pieces, with approximately 75 mm of
length, hinged on one side and slightly curved on the other, thus presenting a beak shape to catch the
fibers that are out and near the comb surfaces. Usually, one of the catcher ends has padding in leather
or another fibrous material. The catcher end has approximately 19 mm of width.
The fiber depressing grid consists of series of metal rods spaced 3.2 mm apart, so that the fibers can
be placed between the combs to press the fibers down between the teeth. The flat fiber depressing
plate consists of a polished metal plate, with approximately 25 mm by 50 mm, with a round knob or
handle on the upper surface through which the plate can be smoothed over the fibers as they are placed
on the surface of the velvet-covered plates. The velvet-covered plates, on which the fibers can be
placed in order, are aluminum plates with approximately 100 mm by 225 mm and 2.4 mm of
thickness, covered on both sides by high-quality velvet, preferably black.
SELECTION OF COTTON
After unrolling the cotton, prepare a representative sample by taking, from a package with 225 g to
450 g, 32 samples (each one with approximately 75 mg) well distributed along the lap, being 16 taken
from one longitudinal half and the rest, from the other half.
Avoid the lap ends and carefully make sure that the portions are taken considering the lap thickness.
To avoid the selection of only long fibers or short fibers, remove all fibers from each sample and do
not let them pass through your fingers.
Weigh eight samples from packages with no more than 112.5 g and weigh 16 samples from packages
weighing 112.5 g to 225 g, all of them well distributed.
Mix the samples in pairs, randomly, and match each pair by pulling and rolling softly on the fingers.
Then, divide each matched pair lengthwise in two approximately equal parts and use one part in the
further mixture (the other part can be discarded or reserved for any other tests or controls).
Repeat the process described on the previous paragraph with the successive halves of the series
bifurcated until it results in only one sample. Arrange the final sample fibers softly in parallel position,
pulling and rolling them on the fingers. Retain all fibers, including, as much as possible, the ones
tangled and the masses of braided fibers, discarding only unripe seed fragments with fibers and non-
fibrous foreign material, such as petioles, leaves and fragments of integuments.
From the final sample described on the previous paragraph, separate lengthwise a sample with (75 ±
2) mg, weighed accurately. Retain the residue for any necessary test.
PROCEDURE
Using the fiber depressing grid, carefully insert the weighed sample in a comb bank from the cotton
sorter, so that it extends through the combs in approximately straight angles.
With the sorter forceps, hold, by the free ends, a small portion of fibers that extends through the teeth
from the comb closest to the operator; softly take it from the combs and transfer it to the tips of teeth
from the second banks, laying the fibers parallel with each other, linearly and in approximately
straight angles in relation to the teeth sides, releasing as close as possible to the front comb side.
Using the depressing grid, carefully press down the fibers transferred on the comb teeth. Continue the
operation until all fibers are transferred to the second comb bank. During this fiber transfer, let the
combs from the first bank fall successively when and while all protruding fibers are removed.
Turn the equipment 180° and transfer the cotton fibers back to the first comb bank as described
previously.
The ends of the fibers must be carefully smoothed during both transfers, being arranged as close as
possible to the front surface of the proximal comb. Such smoothing may involve removing isolate
fibers from both sides, frontal and distal, of the comb banks and depositing them again in the main
bundle of the combs.
Turn the equipment 180º again. Let successive combs fall, if necessary, to expose the ends of the
longer fibers. It may be necessary to deposit again some loose fibers. Using the forceps, remove the
few more protruding fibers. Thus, continue removing successively the remaining protruding fibers
back to the front side of the proximal comb. Let this comb fall and repeat the series of operations in
the same way until all fibers have been removed. To not disturb the sample seriously and, therefore,
vitiate the fractioning in groups, pull several times (eight to ten) between each pair of combs.
Place the pulls over the velvet-covered plates parallel with each other, as straight as possible, with
the ends as clearly defined as possible, and with the distal parts arranged in a straight line, pressing
them down gently with the flat fiber depressor plate before releasing the pull from the forceps. Use
no less than 50 and no more than 100 pulls to fraction the sample.
Group all fibers that have length of 12.5 mm or more and weigh the group until tenths of milligram.
Likewise, group all fibers that have length of 6.25 mm or less and weigh the same manner. Finally,
group the remaining fibers, of intermediate lengths, and weigh. The sum of the three weights must
not be more than 3 mg different from the initial sample weight. Divide the mass of each one of the
two first groups by the sample mass to obtain the percentage in weight of fiber on the two length
ranges.
Detector tubes are sealed cylindric tubes comprised of an inert clear material, built in order to enable
the passage of gas. They have reagents adsorbed in inert substrates appropriate to view the substance
to be detected and may have preliminary layers and/or adsorbent filters to eliminate the impurities
that interfere with the substance to be detected. Such layers have a single reagent for detecting a
certain impurity or several reagents to detect several substances (single-layer or multi-layer tube).
The assay is conducted passing the necessary volume of gas to be analyzed through the indicator tube.
The extension of the colored layer or the intensity of color change in a graded scale allows assessing
the presence of impurities.
The user must ensure the adequacy of detector tubes for the intended use and they must be used
according to the procedure below or to instructions from the manufacturer.
The gas supply must be connected to adequate pressure regulator and needle valve. Connect a flexible
tube to a T for adjusting the flow of gas to be analyzed and for the tube purge, in order to obtain
adequate flow (Figure 1). Couple the indicator tube to the dosing pump and connect the other end to
the T. Operate the pump so that an adequate volume of the gas to be analyzed passes through the tube.
Read the value corresponding to the extension of the colored layer or intensity of color in the graded
scale. If the result is negative, the indicator tube may be checked through a calibration gas with the
adequate impurity.
1 Gas supply; 2 Pressure regulator valve; 3 Needle valve; 4 T-shaped part; 5 Indicator tube; 6 Dosing pump; and 7 Outlet
to atmosphere.
Carbon monoxide: the carbon monoxide detector tube must indicate the minimum concentration of 5
micromol/mol (ppm), with the relative standard deviation of results of no more than 15.0%.
Carbon dioxide: the carbon dioxide detector tube must indicate the minimum concentration of 100
micromol/mol (ppm), with the relative standard deviation of results of no more than 15.0%.
Sulfur dioxide: the sulfur dioxide detector tube must indicate the minimum concentration of 0.5
micromol/mol (ppm), with the relative standard deviation of results of no more than 15.0%.
Nitrogen monoxide and nitrogen dioxide: the nitrogen monoxide and nitrogen dioxide detector tube
must indicate the minimum concentration of 0.5 micromol/mol (ppm), with the relative standard
deviation of results of no more than 15.0%.
The analyzer is comprised of two identical generators of infrared beams: one beam crosses a cell with
the sample and the other crosses a cell with the reference gas. The infrared radiation emitted by a
source is converted to intermittent light through a rotary switch (chopper) and enters the detector
chamber after going through one of the measurement cells. Part of the radiation is absorbed by the
impurity that may exist in the sample cell, producing a difference in the intensity on the two beams
that enter the detector chambers. This difference produces an electric current that is proportional to
the amount of impurity that exists in the sample.
Whenever the equipment is turned on, it must be adjusted as described in the specific monograph for
each gas.
The paramagnetic signal identifies the oxygen in the sample. The principle of the method is based on
the high paramagnetic sensitivity of the oxygen molecule, which has a strong interaction in the
magnetic field, which signal is measured electronically, amplified and converted to a value
transmitted in the oxygen concentration reader.
The equipment must be calibrated periodically. The equipment reading range is from 0 to 100.0%
v/v, with resolution of 0.1%, linearity of ± 0.1% and precision of 0.1%.
For calibrating the equipment, adjust the zero passing standard certified nitrogen gas with minimum
purity of 99.99% v/v through the device until a constant reading is achieved; configure to the scale of
100% passing the calibration gas (standard certified oxygen with minimum purity of 99.99% v/v)
with the same flow used when conducting the calibration from zero until constant reading is achieved.
Procedure: pass the gas to be analyzed through the analyzer with the same flow used at calibration
until constant reading is achieved. Register the sample gas concentration read on the instrument. The
result must be in percentage of volume of oxygen.
The device is comprised of an ultraviolet radiation generator system, with specific wavelength to
determine each gas impurity, formed by an ultraviolet lamp, a collimator and a selective filter, a
reaction chamber, where the gas being assayed circulates, and a system for detection of the radiation
emitted in the specific wavelength, comprised of a selective filter, a photomultiplier tube and an
amplifier. The light beam is periodically interrupted by a rotary switch (chopper) spinning at high
speed.
Whenever the equipment is turned on, it must be calibrated as described in the specific monograph
for each gas.
NO + O3 → NO2 + O2 + hν
For the chemiluminescence reaction to happen, the nitrogenated species must be in the form of NO.
The sample stream is divided into two streams, one going through a converter of NOx into NO and
the other not passing through the converter. The stream that passes through the converter will have a
higher NO concentration than the real one, and the stream that does not go through the converter will
have the actual NO concentration. The difference between both will reveal the concentration of NO2.
Principle of operation: the sample enters the equipment, crosses the capillary and goes to a valve that
divides the sample flow into two streams, one for the reaction chamber and the other for the converter
of NO2 into NO. A flow meter indicates the flow of sample that goes to the chamber. Dry air enters
on the other hole, passes through a flow controller, and goes to the ozone generator that produces the
necessary ozone for the chemiluminescence reaction. Right at the outlet of the reaction chamber, the
PMT (photomultiplier tube) detects the luminescence generated. The concentrations of NO and NOx
are determined and the difference between these concentrations is the concentration of NO2.
This equipment has a detection cell that consists of a thin phosphorus pentoxide film between two
spiraled platinum wires that work as electrodes. Water vapor on the gas to be examined is absorbed
by the diphosphorus pentoxide, which is turned into phosphoric acid, an electric conductor. A direct
voltage applied to the electrodes produces water electrolysis and regeneration of diphosphorus
pentoxide. The value obtained from the electric current, which is proportional to the concentration of
water vapor in the gas examined, is determined. The system is self-calibrated provided that the
Faraday’s law is complied with.
Procedure: collect a sample of the gas to be examined and wait for its stabilization at room
temperature. Purge the cell continuously until a constant value is obtained. Measure the concentration
of water vapor in the gas examined, making sure that the temperature is constant in the system for
introduction of gas in the device.
CORRELATES
6.1 GLASS CONTAINERS
CLASSIFICATION
Type I glass. Neutral glass of borosilicate, non-alkaline type, with high thermal, mechanic and
hydrolytic resistance, with alkalinity of up to 1.0 mL of H2SO4 0.01 M (assay in crushed glass vial).
Targeted at containing medicines; for intravascular application and parenteral use.
Type II glass. Alkali glass of the sodic / calcic type, with high hydrolytic resistance, resulting from
appropriate treatment of the internal surface of type III glass, so that its alkalinity is no more than
0.7 mL of H2SO4 0.01 M for vials with up to 100 mL and 0.2 mL of H2SO4 0.01 M for capacity over
100 mL (assay in whole glass vial). Targeted at containing solutions of parenteral use; neutral and
acid solutions that don’t have their pH changed.
Type III glass. Alkali glass of sodic / calcic type, with medium hydrolytic resistance, but with good
mechanical resistance, without any surface treatment, with maximum alkalinity of 8.5 mL of 0.01 M
H2SO4 (assay in crushed glass vial). Targeted at containing solutions of oral and topical use; it can
be used for parenteral solutions, when approved by stability assays.
NP (non-parenteral) type glass. Alkali glass of the sodic / calcic type, with low hydrolytic resistance
and high alkalinity, of no more than 15 mL of H2SO4 0,01 M (assay in crushed glass vial). Indicated
for containing non-parenteral products, that is, of oral and topical use.
• Autoclave with temperature control of (121 ± 1.0) °C, equipped with thermometer, manometer,
safety valve and shelf for supporting no less than 12 vials.
• Ball mill with hardened steel stricture and polished steel spheres or mortar in tempered steel with
the specifications on Figure 1.
Wash no less than six vials, selected randomly, with bi-distilled or deionized water, and dry them in
a clean and dry air current.
If necessary, cut the vials and transfer and crush 30 g to 40 g of glass using the ball mill or mortar.
Pass the crushed glass through a sieve n. 20 and transfer the portion retained in the sieve to the ball
mill or mortar again. Repeat the operations of grinding and passing the fragments through the sieve
until no less than 2/3 of the material has gone through sieve n. 20. Combine all portions of crushed
glass that went through sieve n. 20 and pass through a sieve n. 40. Grind the portion retained on the
sieve and repeat the operation.
Combine the portions of crushed glass that went through sieve n. 40 and transfer to the assembled set
of sieves n. 40 and n. 50. Shake horizontally for five minutes. Collect 12.0 g of crushed glass that
went through the n. 40 sieve, but did not go through the n. 50 sieve, and store it in a desiccator until
being used in the test.
Spread the sample of crushed glass over a piece of satin paper and pass the magnet, to remove possible
iron fragments that may have been introduced during the crushing procedure.
Transfer the sample to a 250 mL Erlenmeyer flask and wash the glass particles with six portions of
30 mL of acetone PA, agitating for approximately 30 seconds in each procedure, and carefully decant
the acetone. After washing, the sample must be free from glass powder blocks and the grain surface
must be practically free from adherence of fine particles. Dry the material for 20 minutes at 140 °C.
The sample must be tested up to 48 hours after drying and, in this case, it must be maintained in a
desiccator.
Weigh 10.0 g of crushed glass, transfer to a 250 mL Erlenmeyer flask, prepared in advance with bi-
distilled or deionized water in bath at 90 °C for no less than 24 hours or at 121 °C for one hour, and
add 50 mL of bi-distilled or deionized water.
As blank, use a 250 mL Erlenmeyer flask, prepared in advance in bi-distilled or deionized water in
bath at 90 °C for no less than 24 hours or at 121 °C for one hour, and add 50 mL of bi-distilled or
deionized water.
Close the Erlenmeyer flasks with an inverted beaker or aluminum foil, washed in advance with bi-
distilled or deionized water.
Take the vials and cool them immediately in running water. After cooling, decant the water from the
Erlenmeyer flask and wash the crushed glass with four portions of 15 mL of bi-distilled or deionized
water. Add five drops of methyl red solution and titrate, immediately, with sulfuric acid 0.01 M. If
the expected volume of solution to be used in titration is inferior to 10 mL, use a micro-burette.
Register the volume of sulfuric acid used in titration and correct the value in relation to the volume
of blank.
Limits:
The maximum alkalinity value for the type I glass vial is of 1.0 mL of H2SO4 0.01 M for 10 g of
crushed glass.
The maximum alkalinity value for the type III glass vial is of 8.5 mL of 0.01 M H2SO4 for 10 g of
crushed glass.
The maximum alkalinity value for the NP type glass vial is of 15 mL of H2SO4 0.01 M for 10 g of
crushed glass.
Wash vials, selected randomly, with bi-distilled or deionized water, and dry them in a clean and dry
air current. Add a volume of bi-distilled or deionized water corresponding to 90% of the total capacity
of the vial, determined as described in Total volumetric capacity (6.1.3).
Close the vials with aluminum foil washed in advance with bi-distilled or deionized water and put
them in autoclave. Submit them to the following treatment:
• heat the autoclave at 100 °C, with the exhaust valve opened, for 10 minutes;
• increase the autoclave temperature after closing the exhaust valve, by 1 °C/minute, until reaching
(121 ± 1) °C;
• maintain the temperature of (121 ± 1) °C for 60 minutes;
• lower the temperature by 0.5 °C/minute, until reaching 100 °C, discharging the pressure until
achieving atmospheric pressure;
• open the autoclave only after reaching the temperature of 95 °C;
• transfer the vials to a water bath at 80 °C. Add cold water, taking care to avoid contamination of
the extraction solution, and the cooling time must not exceed 30 minutes.
After cooling, combine the extraction solution from each of the vials. Measure the volume as
registered on Table 1 and transfer to a 250 mL Erlenmeyer flask.
As blank, use a 250 mL Erlenmeyer flask and add the same volume of bi-distilled or deionized water.
Transfer five drops of methyl red solution for each 25 mL of extraction solution and titrate,
immediately, with hydrochloric acid 0.01 M, using a micro-burette. Register the volume of
hydrochloric acid 0.01 M used in titration and correct the value in relation to the volume of blank.
Limits:
The maximum alkalinity value must not exceed the values indicated on Table 2.
Table 2 – Maximum alkalinity according to the glass type and the volumetric capacity of the vial.
Volumetric capacity of the Maximum volume of HCl 0.01 M (mL) for 100 mL of extraction solution
flask (mL) Types I and II Type III
≤1 2.0 20.0
From 1 to 2 1.8 17.6
From 2 to 5 1.3 13.2
From 5 to 10 1.0 10.2
From 10 to 20 0.80 8.1
From 20 to 50 0.60 6.1
From 50 to 100 0.50 4.8
From 100 to 200 0.40 3.8
From 200 to 500 0.30 2.9
> 500 0.20 2.2
Rinse three or more vials, selected randomly, with bi-distilled or deionized water twice and dry them
in a clean and dry air current. Add a volume of bi-distilled or deionized water corresponding to 90%
of the total capacity of the vial, determined as described in Total volumetric capacity (6.1.3). Close
the flasks with an inverted beaker or aluminum foil, washed in advance with bi-distilled or deionized
water.
Combine the volume of extraction solution from several vials in a graded cylinder and transfer
100.0 mL to a 250 mL Erlenmeyer flask. Add five drops of methyl red solution and immediately
titrate with sulfuric acid 0.01 M. Complete the titration within 60 minutes after opening the autoclave.
Register the volume of sulfuric acid used in titration and correct the value in relation to the volume
of blank (100 mL of bi-distilled or deionized water at the same temperature and with the same amount
of indicator).
Limits:
The maximum alkalinity value for the type II glass vial is of 0.7 mL of H2SO4 0.01 M for vials with
up to 100 mL of volumetric capacity.
The maximum alkalinity value for the type II glass vial is of 0.2 mL of H2SO4 0.01 M for vials with
more than 100 mL of volumetric capacity.
6.1.2 ARSENIC
EQUIPMENT, MATERIALS AND REAGENTS
• Autoclave with temperature control of (121 ± 1.0) °C, equipped with thermometer, manometer,
safety valve and shelf for supporting no less than 12 vials;
• oven for drying with temperature of 140 °C;
• beaker or aluminum foil;
• 250 mL Erlenmeyer flask;
• 100 mL graded cylinder;
• bi-distilled or deionized water, with maximum conductivity of 0.15 μS/cm (or 6.67 MΩ/cm) at 25
°C.
PROCEDURE
Wash vials, selected randomly, with bi-distilled or deionized water and dry them in a clean and dry
air current. Add a volume of bi-distilled or deionized water corresponding to 90% of the total capacity
of the vial, determined as described in Total volumetric capacity (6.1.3).
Close the vials with aluminum foil washed in advance with bi-distilled or deionized water and put
them in autoclave. Submit them to the following treatment:
• heat the autoclave at 100 °C, with the exhaust valve opened, for 10 minutes;
• increase the autoclave temperature after closing the exhaust valve, by 1 °C/minute, until reaching
(121 ± 1) °C;
• maintain at temperature of (121 ± 1) °C for 60 minutes;
• lower the temperature by 0.5 °C/minute, until reaching 100 °C, discharging the pressure until
achieving atmospheric pressure;
• open the autoclave only after reaching the temperature of 95 °C;
• transfer the vials to a water bath at 80 °C. Add cold water, carefully, to avoid contamination of the
extraction solution, and the cooling time must not exceed 30 minutes.
After cooling, combine the extraction solution from each of the flasks to obtain 35 mL and transfer
to a 250 mL Erlenmeyer flask.
Proceed as described for Limit test for arsenic (5.3.2.5). No more than 1 μg/g.
PROCEDURE
Select six units randomly. Tare the balance with the dry and empty vial. Fill the vial with bi-distilled
water until the termination sealing surface (vial closing region, also named neck, finish or finishing),
keeping the external surface completely dry; for ampoules, the filling must be conducted until the
height of point A (Figure 1).
Determine the water temperature during the execution of the assay and make sure that the water
temperature does not vary more than 1 °C. Weigh the full vial and determine the mass of water
contained in it.
Calculate the volume of the vial dividing the mass of water by its density, at the assay temperature,
using the data listed on Table 1 for distilled water.
RESULTS
The results expressed in mL, with one decimal place, must comply with the specifications indicated.
Plastic items are identified and characterized by infrared spectroscopy and differential scanning
calorimetry. This section describes the procedures from tests and rules for identification and
characterization of different types of plastic. The level of verification is based on direct or indirect
contact with the medicine, and the risk is based on the route of administration.
Plastics may contain residues from the polymerization process, plasticizers, stabilizers, antioxidants,
pigments and lubricants. Factors such as the composition of plastic, processing and procedures for
cleaning, surface treatment, means of contact, colorants, adhesives, absorption and permeability of
preservatives, as well as storage conditions, may also affect the suitability of a plastic for a specific
use. Tests on extractable substances are planned to characterize the components extracted and identify
possible migrants. The degree or extension of tests to extract substances from a component depends
on the purpose of use and the level of risk of impacting negatively the product efficacy. This chapter
describes the tests on specific extractable substances for resins of polyethylene, polypropylene,
poly(ethylene terephthalate) and poly(ethyelene terephthalate glycol). All other plastics must be
tested as described on Physicochemical tests from Test methods (6.2.1.3). The Buffer capacity test
must be tested for containers targeted at containing a liquid product.
Plastic components used for high risk products, such as the ones targeted at inhalation, parenteral and
ophthalmic preparations, are tested using the Biological Assays from Test methods (6.2.1.3).
Plastic containers targeted at containing parenteral products must meet the requirements from
Biological assays and from Physicochemical tests. Rules are also provided for polyethylene
containers used to contain dry oral pharmaceutical dosage forms, not targeted at constitution in
solution.
The rules and assays described in this section characterize containers and components, made from
low- or high-density polyethylene from homopolymeric or copolymeric resins.
All polyethylene components are subject to infrared spectroscopy and differential scanning
calorimetry tests. When stability studies are conducted to determine the validity date of a special
pharmaceutical preparation in a suitable polyethylene container, any other polyethylene container that
complies with these requisites may be equally used to contain the pharmaceutical preparation in
question, provided that the adequate stability programs are extended to include the alternative
container to ensure that the identity, strength, quality and purity of the pharmaceutical preparation are
maintained throughout the validity period.
ASSAYS
High-density polyethylene
Infrared spectroscopy. Use the attenuated total reflection accessory, as described on the item Mid-
infrared (5.2.14). The corrected sample spectrum must present bands with higher absorption only on
the same wavelengths as the reference standard spectrum.
Differential scanning calorimetry. Proceed as described in Thermal analysis from Test methods
(6.2.1.3). The sample thermogram must be similar with the one from the reference standard,
determined in a similar manner, and the endothermal (thawing) temperature on the sample
thermogram must not differ by more than 6.0 °C from reference standards.
Heavy metals and non-volatile residue. Prepare extracts from the sample as described on
Physicochemical tests, in Test methods (6.2.1.3), with area sample equivalent to 60 cm2, without
considering the thickness, for every 20.0 mL of Extraction medium.
Heavy Metals. The containers must meet the requirements for Heavy metals on Physicochemical
tests, in Test methods (6.2.1.3).
Substances used in contact with oral liquids. Proceed as described in the Buffer capacity from
Physicochemical tests, Test methods (6.2.1.3).
Low-density polyethylene
Infrared spectroscopy. Use the attenuated total reflection accessory, as described on the item Mid-
infrared (5.2.14). The corrected sample spectrum must present bands with higher absorption only on
the same wavelengths as the reference standard spectrum.
Heavy metals and non-volatile residue. Prepare extracts from the sample as described on Sample
preparation in Physicochemical tests from Test methods, with area sample equivalent to 60 cm2,
without considering thickness, for every 20.0 mL of Extraction medium.
Heavy metals. The containers must meet the requirements for Heavy metals from Physicochemical
tests, in Test methods (6.2.1.3).
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RC6.2-00
Substances used in contact with oral liquids. Proceed as described in the Buffer capacity from
Physicochemical tests, in Test methods (6.2.1.3).
Polypropylene has a distinctive infrared spectrum and characteristic thermal properties. It has density
of 0.880 g/cm3 to 0.913 g/cm3. The permeability properties of molded polypropylene containers may
be altered when re-powdered polymer is incorporated, depending on its ratio in the final product.
Other properties that may affect the suitability of polypropylene used in containers for packaging
medicines include permeability to oxygen and humidity, elasticity modulus, flow index, resistance to
breaking under environmental tension, and level of crystallinity after molding.
The rules and assays provided characterize containers in polypropylene, made from homopolymers
or copolymers, which are adequate for containing dry solid and liquid pharmaceutical dosage forms.
Considering that adequate stability studies have been conducted to determine the validity date of a
specific pharmaceutical preparation in a suitable polypropylene container, any other polypropylene
container that complies with these requisites may be equally used to contain the same pharmaceutical
preparation, provided that the adequate stability programs are extended to include the alternative
container, to ensure that the identity, strength, quality and purity of the pharmaceutical preparation
are maintained throughout the validity period.
ASSAYS
Infrared spectroscopy. Use the attenuated total reflection accessory, as described on the item
Infrared absorption spectrophotometry (5.2.14). The corrected spectrum of the sample must present
bands with higher absorption only in the same wavelengths of the spectrum of the respective reference
standard (polypropylene homopolymer or copolymer) determined in a similar manner.
Differential scanning calorimetry. Proceed as described in Thermal analysis from Test methods
(6.2.1.3). The endothermal (thawing) temperature on the thermogram must not differ by more than
6.0 °C from the reference standards for homopolymers. The endothermal temperature obtained from
the polypropylene copolymer sample thermogram must not differ by more than 12.0 °C from the
standards of this substance.
Heavy metals and non-volatile residue. Prepare extracts from samples as described on Sample
preparation, from Physicochemical tests, in Test methods (6.2.1.3), with a portion of 60 cm2, without
considering the thickness, for every 20.0 mL of Extraction medium.
Heavy metals. The containers must meet the requirements for Heavy metals from Physicochemical
tests, in Test methods (6.2.1.3).
Note: hexane and alcohol are flammable. When evaporating these solvents, use an air current with
water bath; when drying the residue, use explosion-proof oven.
Substances used in contact with oral liquids. Proceed as described in the Buffer capacity from
Physicochemical tests, in Test methods (6.2.1.3).
PET copolymer resins have physical and spectral properties similar to PET and, for practical
purposes, are handled as PET. Assays and specifications provided in this section to characterize PET
resins and containers also apply to copolymer residues and to containers made from them.
Usually, PET and its copolymer resins present a high level of order in their molecular structure. As a
result, they present a characteristic thermal behavior dependent on the composition, including a glass
transition temperature of approximately 76 °C and a melting temperature of approximately 250 °C.
These resins have a particular infrared absorption spectrum that allows their differentiation from other
plastic materials, such as polycarbonate; polystyrene; polyethylene; poly(ethylene terephthalate
glycol) (PETG) resins. PET and its copolymer resins have density between 1.3 and 1.4 g/cm3 and
minimum intrinsic viscosity of 0.7 dL/g, which corresponds to an average molecular mass of
approximately 23,000 Da.
PETG resins are polymers with high molecular mass prepared by condensing ethylene glycol with
dimethyl terephthalate, or terephthalic acid, and with 15 to 34% of molar 1,4-hexanedimethanol.
PETG resins are clear, amorphous polymers with glass transition temperature of approximately 81
°C and without a crystalline melting point, as determined by the differential scanning calorimetry.
PETG resins have a particular infrared absorption spectrum that allows distinguishing it among other
plastic materials, including PET. PETG resins have density of approximately 1.27 g/cm3 and
minimum intrinsic viscosity of 0.65 dL/g, which corresponds to an average molecular mass of
approximately 16,000 Da.
PET and PETG resins do not have any plasticizer, processing support or antioxidants. When colorants
are used in manufacturing PET and PETG containers, they must not migrate to the liquid.
The rules and assays provided in this section characterize polyethylene terephthalate (PET) and
polyethylene terephthalate glycol (PETG) containers that are used to contain liquid oral
pharmaceutical dosage forms. Considering that adequate stability studies have been conducted to
determine the validity date of a particular liquid pharmaceutical preparation in a container that
complies with the requisites for PET or PETG containers, any other container from these substances
that complies with these requisites may be equally used to contain the same pharmaceutical
preparation, provided that the adequate stability programs are extended to include the alternative
container, to ensure that the identity, strength, quality and purity of the pharmaceutical preparation
are maintained throughout the validity period. The suitability of a specific PET or PETG container to
be used for dispensing a specific liquid oral pharmaceutical preparation must be established through
adequate tests.
ASSAYS
Infrared spectroscopy. Use attenuated total reflection accessory, proceed as described in Ultraviolet,
visible and infrared spectrometry (5.2.14). The corrected sample spectrum presents bands with higher
absorption only on the same wavelengths as the spectrum from reference standards, determined in a
similar manner.
Differential scanning calorimetry. Proceed as described on the item Thermal analysis in Test
methods. For polyethylene terephthalate, the sample thermogram must be similar to the one from the
reference standard, determined in a similar manner; the sample melting point (Tm) must not differ
from the reference standards by more than 9 °C and from the glass transition temperature by more
than 4 °C. For polyethylene terephthalate glycol, the sample thermogram must be similar to the one
from the reference standard, determined in a similar manner; the glass transition temperature (Tg)
from the sample must not differ by more than 6 °C from the reference standards.
Extraction of colorants. Select three containers for the assay. Cut a relatively flat part from the side
wall of a container and trim it to the necessary dimension to adjust the sample to the
spectrophotometer support. Perform a scan (5.2.14) to obtain the visible spectrum of 350-700 nm
from the side wall. With approximation of 2 nm, determine the maximum absorbance wavelength.
Fill the two remaining containers with 50% ethyl alcohol for PET containers and 25% ethyl alcohol
for PETG containers. Prepare the containers with impermeable seals, such as an aluminum foil, and
close with the lids. Fill with the corresponding solvent from a glass container of the same capacity as
the containers being tested, prepare it with a impermeable seal, such as an aluminum foil, and close
with a lid. Incubate the containers being tested and the glass container at 49 °C for 10 days. Remove
the containers and wait until they reach room temperature. Concomitantly, determine the absorbances
(5.2.14) of the solutions being tested in cells with 5 cm on the maximum absorbance wavelength,
using the corresponding solvent from the glass container as blank. For both solutions being tested,
the absorbance values obtained must be lower than 0.01.
Extraction media.
Purified water
Ethyl alcohol 50%. Dilute 125 mL of ethyl alcohol in water for 238 mL of solution and homogenize.
Ethyl alcohol 25%. Dilute 125 mL of Ethyl alcohol 50% in water for 250 mL of solution and
homogenize.
n-Heptane.
General procedure. Use an extraction medium of Ethyl alcohol 50% for PET containers and Ethyl
alcohol 25% for PETG. For each extraction medium, fill a sufficient number of test containers with
90% of their nominal capacity to obtain no less than 30 mL. Fill a corresponding number of glass
containers with Purified water, the same amount of containers with Ethyl alcohol 50%, or Ethyl
alcohol 25% and the same number of glass containers with n-Heptane to be used as blank of
extraction media. Put impermeable seals, such as aluminum foil, on the containers and cover them.
Incubate the test containers and the glass containers at 49 °C for 10 days. Remove the test containers
with the samples and the blanks from the extraction medium and store them at room temperature. Do
not transfer samples of extraction medium to alternative storage containers.
Heavy metals. Pipette 20 mL of Purified water extracted from the test containers, filtered as
necessary, put in one or two 50 mL tubes for comparing the color, and store the remaining Purified
water to use in the Ethylene glycol test. Adjust the pH of the extract between 3.0 and 4.0 with acetic
acid M or ammonium hydroxide 6 M using a narrow range pH indicator paper. Dilute with water to
approximately 35 mL and homogenize. Pipette 2 mL of the Standard lead solution (10 ppm Pb)
(5.3.2.3), prepared on the day of use; transfer to a second color comparison tube and add 20 mL of
Purified water. Adjust the pH between 3.0 and 4.0 with acetic acid M or ammonium hydroxide 6 M
using a narrow range pH indicator paper. Dilute with water to approximately 35 mL and homogenize.
Add to each tube 1.2 mL of thioacetamide RS and 2 mL of Buffer acetate pH 3.5 (5.3.2.3), dilute with
water to 50 mL of solution and homogenize. Any color produced within 10 minutes in the tube with
Purified water extracted from test containers must not be more intense than the one from the tube
with the Standard lead solution (10 ppm Pb), both viewed on a white surface (limit 1 ppm).
Total terephthaloyl. Determine the absorbance of extract of Ethyl alcohol 50% or Ethyl alcohol 25%
in a cell with 1 cm, on the maximum absorbance wavelength at approximately 244 nm (5.2.14), using
as blank the one corresponding to the extraction medium. The extract absorbance must not exceed
0.150, which corresponds to no more than 1 ppm of the total terephthaloyl from the medium.
Determine the absorbance of extract of n-Heptane in a cell with 1 cm, on the maximum absorbance
wavelength at approximately 240 nm (5.2.14), using as blank the n-Heptane extraction medium. The
extract absorbance must not exceed 0.150, which corresponds to no more than 1 ppm of terephthaloyl
from the medium.
Ethylene glycol.
Periodic acid solution. Dissolve 125 mg of periodic acid in 10 mL of water.
Diluted sulfuric acid. For 50 mL of water, add slowly and in constant agitation 50 mL of sulfuric acid
and wait until it reaches room temperature.
Sodium bisulfite solution. Dissolve 0.1 g of sodium bisulfite in 10 mL of water. Use this solution in
up to seven days.
Disodium chromotropate solution. Dissolve 100 mg of disodium chromotropate in 100 mL of sulfuric
acid. Protect the solution from light and use it in up to seven days.
Standard solution. Dissolve an amount, accurately weighed, of ethylene glycol in water and dilute,
quantitatively, step by step if necessary, to obtain a solution with concentration of approximately
1.0 μg/mL.
Sample solution. Use the extract in Purified water.
after the addition of Disodium chromotropate solution. Add, carefully, 6 mL of sulfuric acid to each
flask, homogenize and wait for the solutions to reach room temperature.
Note: the dilution of sulfuric acid produces considerable heat and may cause ebullition of solution.
Make this addition carefully. Sulfur dioxide gas will be released. Using an exhaust chamber is
recommended.
Dilute each solution with sulfuric acid diluted until completing the volume and homogenize.
Concomitantly, determine the absorbances (5.2.14) of the solutions from the Standard solution and
the Sample solution in cells with 1 cm, in the maximum absorbance wavelength at approximately
575 nm, using as blank the solution taken from the extraction medium in Purified water. The
absorbance of the solution obtained from the Sample solution is not superior to the one of the solution
obtained from the Standard solution, corresponding to no more than 1 ppm of ethylene glycol.
TEST METHODS
Equipment. Use an infrared spectrophotometer capable of correcting to the white spectrum and
equipped with an attenuated total reflection and an internal reflection KRS-5 plate. The KRS-5 crystal
with 2 mm of thickness, and incidence angle of 45°, provides a sufficient number of reflections.
Sample preparation. Cut two flat portions representing the average thickness of the container wall,
and trim them as necessary, to obtain adequate segments to assemble in the multiple internal reflection
accessory; To avoid scratching the surface, clean the samples with dry paper or, if necessary, with a
soft cloth moistened with methyl alcohol and wait until drying. Firmly couple the samples on both
sides of the KRS-5 internal reflection plate, ensuring the adequate surface of contact. Before placing
the samples on the plate, compress them obtaining thin even films to be exposed at temperatures of
approximately 177 °C, under high pressure (15,000 psi or more).
Procedure. Put the coupled parts of the sample in the multiple internal reflection accessory and place
the set in the infrared spectrophotometer light beam. Adjust the position of the sample and the
equipment mirrors to allow maximum transmission of light by the non-attenuated reference beam.
Complete the adjustments of the accessory and attenuate the reference beam, to allow total deflection
scale during the sample scanning. Determine the infrared spectrum from 3500 cm-1 to 600 cm-1 for
polyethylene and polypropylene and from 4000 cm-1 to 400 cm-1 for PET and PETG.
Thermal analysis
Procedure. Cut a section with an approximate weight of 12 mg and place it in the compartment for
the sample. The close contact between the compartment and the thermoelement is essential for the
reproducibility of results. Determine the thermogram under nitrogen, using the heating and cooling
conditions as specified for the type of resin and use an equipment capable of making the
determinations.
For polyethylene. Determine the thermogram under nitrogen at temperatures between 40 °C and 200
°C, at a heating rate between 2 °C and 10 °C per minute, followed by cooling to 40 °C, at a rate
between 2 °C and 10 °C per minute.
For polypropylene. Determine the thermogram under nitrogen at temperatures that range between
room temperature and 30 °C above the melting point. Maintain the temperature for 10 minutes, then
cool down to 50 °C below the maximum crystallization temperature at a rate of 10 °C to 20 °C per
minute.
For poly(ethylene terephthalate). Heat the sample from room temperature to 280 °C at a heating
rate of approximately 20 °C per minute. Maintain the sample at 280 °C for one minute. Cool the
sample quickly down to room temperature and reheat it to 280 °C at a heating rate of approximately
5 °C per minute.
For poly(ethylene terephthalate) glycol. Heat the sample from room temperature to 120 °C at a
heating rate of approximately 20 °C per minute. Maintain the sample at 120 °C for one minute. Cool
the sample quickly down to room temperature and reheat it to 120 °C at a heating rate of
approximately 10 °C per minute.
Biological assays
The biological assays in vitro are conducted according to the procedures established in Biological
reactivity tests in vitro (6.2.5). The components that comply with requisites from tests in vitro do not
need to be submitted to additional tests. No designation of class of plastic is assigned to these
materials. The materials that do not comply with requisites from tests in vitro are not adequate for use
as medicine containers.
If the class designation is necessary for plastics and other polymers that comply with the requisites
included in Biological reactivity tests in vitro (6.2.5), conduct the adequate test in vivo specified for
Classification of plastics in Biological reactivity tests in vivo (6.2.6).
Physicochemical tests
The following tests, targeted at determining the physical and chemical properties of plastics and their
extracts, are based on the extraction of plastic material, being essential that the designated amount of
plastic is used. Additionally, the surface area specified must be available for extraction at the
temperature determined.
Test parameters:
Extraction medium. Unless directed otherwise in a specific test to be followed, use Purified water
as extraction medium, maintaining the temperature at 70 °C during the extraction for the Sample
preparation.
Blank. Use Purified water where the blank is specified on the following tests.
Equipment. Use water bath and Extraction containers, as described in Biological reactivity tests in
vivo (6.2.6). Proceed as described on Equipment preparation in Biological reactivity tests in vivo
(6.2.6). The containers and equipment do not need to be sterile.
Sample preparation. From a homogeneous sample of plastic, use one aliquot for every 20 mL of
extraction medium, equivalent to 120 cm2 of the total surface area (combining both sides), and
subdivided into strips of, approximately, 3 mm of width and close to 5 cm of length. Transfer the
subdivided sample to a 250 mL type I glass graded cylinder, with cap, and add approximately 150 mL
of Purified water. Shake for approximately 30 seconds, empty it, discard the liquid and repeat a
second wash.
Extraction for sample preparation. Transfer the ready Sample preparation to an adequate
extraction vial and add the requested amount of extraction medium. Extract for 24 hours by heating
in water bath at the temperature specified for the extraction medium. Cool to temperatures not below
20 °C. Pipette 20 mL of the extract prepared to an adequate container. Use this part on the test for
Buffer capacity. Immediately decant the residual extract in an adequate clean container and close it.
Residue by incineration (5.2.10). It is not necessary to perform this test when the result from the
Non-volatile residue test does not exceed 5 mg. Proceed with obtaining residues, from the Extract for
sample preparation and Blank described in the test for Non-volatile residue above, using, if necessary,
more sulfuric acid for the same amount in each crucible. The difference between the amounts obtained
of ignition residue from the Extract for sample preparation and Blank must not be superior to 5 mg.
Heavy metals. Pipette 20 mL of the Extract from sample preparation, filtered, if necessary, to one
of the two 50 mL tubes for color comparison. Adjust the pH between 3.0 and 4.0 with acetic acid M
or ammonium hydroxide 6 M using a narrow range pH indicator paper. Dilute with water to
approximately 35 mL and homogenize.
Pipette 2 mL of Standard lead solution (10 ppm Pb) (5.3.2.3), transfer to the second tube for color
comparison and add 20 mL of Blank. Adjust the pH between 3.0 and 4.0 with acetic acid M or
ammonium hydroxide 6 M using a narrow range pH indicator paper. Dilute with water to
approximately 35 mL and homogenize. Add to each tube 1.2 mL of thioacetamide RS and 2 mL of
Buffer acetate pH 3.5 (5.3.2.3), dilute with water to 50 mL of solution and homogenize. Any color
produced within 10 minutes in the preparation that has the Extract from sample preparation extracted
from test containers must not be more intense than in the Standard preparation, both viewed on a
white surface (1 ppm in the extract).
Buffer capacity. Titrate, potentiometrically, the 20 mL aliquots, collected in advance, from the
Extract from Sample preparation to a pH 7.0, using 0.010 M hydrochloric acid or 0.010 M sodium
hydroxide, as necessary. Treat, in a similar manner, a 20 mL aliquot of Blank. If the same titrant is
necessary for both titrated, the difference between the two volumes must not be superior to 10 mL;
and if acid is necessary either for the Extract from sample preparation or for the Blank, and the alkali
for the other, the total of the two volumes requested must not be superior to 10 mL.
For caps formulated with natural or synthetic elastomer substances, used for long-term storage. It is
not applicable to caps made of silicone elastomer, but it applies to silicone-treated caps, such as
dimethicone, and caps coated with other lubricant materials, such as materials chemically bonded or
mechanically bonded to the cap.
The following comments refer only to laminated caps or caps coated with materials targeted at
providing or working as a barrier to the elastomer base, such as poly(tetrafluorethylene) (PTFE) or
varnished coatings. It is not permitted to use a material with the purpose of transforming a cap that is
not within the specific requirements for compliance. However, all physicochemical tests apply to the
base formula of such caps, as well as to the laminated or coated caps. The functionality tests must be
conducted using laminated or coated elastomer caps. The biological assays apply to coated or
laminated materials, as well as to the base formula. The biological assays may be conducted in
laminated or coated caps or materials and in non-laminated and non-coated caps, and the results must
be reported separately. The base formula, used in physicochemical or biological assays, must comply
with the specifications from a cap with coating barrier that must be similar to the cap coating in
configuration and size.
The tests from this section are limited to elastomer caps from Types I and II, with the Type I caps
being used for aqueous preparations and the Type II caps usually being targeted at non-aqueous
preparations. If a cap does not comply with all requirements from the Type I test, but complies with
requirements for the Type II test, the cap receives the final classification of Type II.
This section proposes an initial triage to identify elastomer caps that can be adequate for use with
injectable preparations, based on their biological compatibilities, the physicochemical properties of
their aqueous extracts, and their functionalities. All elastomer caps adequate for use in injectable
preparations comply both with the Type I and Type II test limits. However, this specification does
not have the purpose of being a single criterion of assessment for selection of such caps.
Among the requisites for assessing caps that are beyond the scope of this section, there is the
establishment of identification tests and specifications for the cap, the cap checking, physicochemical
compatibility of the product, identification and determination of safety of filterable caps found in the
product package, checking of the product package functionality under real storage conditions, and
conditions for use.
The cap user must obtain from the supplier a guarantee that the cap composition does not vary and
that it is the same one used in the compatibility test. When the supplier informs the end user about
changes in the composition, the compatibility test must be repeated, totally or partially, depending on
the nature of changes.
CHARACTERISTICS
The elastomer caps are translucent or opaque, and do not have characteristic coloring, depending on
the additives used. They are homogeneous and practically free from luminous and accidental
materials, such as fibers, foreign particles, and rubber residues.
IDENTIFICATION
The caps are made from a broad variety of elastomeric materials and optional polymeric coatings.
Therefore, this section does not specify identification tests involving all possible presentations of
caps. The cap supplier and the finished product manufacturer are responsible for checking the cap
formulation and any coated or laminated materials used, according to the adequate identification tests.
Examples of some analytical tests that can be used include specific density, ash analysis,
determination of sulfur content, chromatography in thin layer of extract, ultraviolet absorption
spectrophotometry of the extract, or absorption spectrophotometry.
TEST PROCEDURES
The elastomer caps must be in compliance with the biological, physicochemical and functional
requirements. Since the elastomer caps are processed by the supplier before the distribution to the end
user, the supplier must demonstrate the compliance of the caps exposed with the processing or
sterilization steps. Likewise, if the elastomer caps received by the end user are processed, or sterilized,
subsequently, the end user is responsible for proving the continued compliance of the subsequent caps
to the processing or sterilization conditions. This is important if the caps are exposed to processes or
conditions that may have significant impact on the biological, physicochemical or functional
characteristics of the cap, such as gamma radiation.
For caps that are usually lubricated with silicone before use, it is permitted to conduct the
physicochemical test in non-lubricated caps to avoid potential interference from method and/or
difficulties in interpreting the test results. For caps provided with other non-occlusive lubricants, all
tests must be conducted using the coated cap.
For coated caps, or laminated with coatings targeted at granting a barrier function, such as PTFE, or
varnished coatings, physicochemical tests will be applied to the elastomer with non-coated base, as
well as to coated caps. The non-coated cap submitted to physicochemical tests must be similar to the
coated cap in size and configuration. The end users of coated caps are also responsible for proving
the compliance of these caps with the physicochemical specifications, processed or treated in a way
that simulates the conditions normally employed by the end user before use.
In all cases, it is adequate to document the conditions for cap processing, pre-treatment, sterilization
or lubrication when the results are reported.
The Table 1 summarizes the requirements from cap tests and responsibilities from the supplier and
the end user.
Table 1 – Requirements from cap tests and responsibilities from the supplier.
Types of caps (as supplied or used) Physicochemical tests Functionality tests Biological assays
Caps with or without silicone coating The tests must be conducted The tests must be conducted The tests must be conducted
The use of silicone is optional The use of silicone is optional The use of silicone is optional
Responsibility: Responsibility: Responsibility:
supplier and end user supplier and end user supplier and end user
Caps with lubricant coatings The tests must be conducted in The tests must be conducted in The tests must be conducted in
(non-occlusive materials, not silicone) coated caps coated caps coated caps
Responsibility: Responsibility: Responsibility:
supplier and end user supplier and end user supplier and end user
Caps with occlusive coatings The tests must be conducted in The tests must be conducted in The tests must be conducted in
coated caps coated caps coated caps
Responsibility: Responsibility: OR:
supplier and end user supplier and end user The tests must be conducted in non-
AND: coated caps (base formula) and
The tests must be conducted in non- laminated/coated material (report
coated caps (base formula) the results separately)
Responsibility: Responsibility:
supplier supplier and end user.
Biological assays
Two test stages are indicated. The first stage is conducting the test in vitro. The materials that do not
comply with requirements from the test in vitro are submitted to the second stage of tests in vivo, as
described in Biological reactivity tests in vivo (6.2.6). Materials that meet the requirements for tests
in vitro do not need to be submitted to test in vivo. Type I and Type II caps must be in compliance
with the biological reactivity tests in vitro and in vivo.
Put entire caps, not cut out, corresponding to a surface area of (100 ± 10) cm2 in an adequate glass
container. Cover the caps with 200 mL of purified water or water for injection. If it is not possible to
obtain a cap with the surface area prescribed using caps not cut, select a number of caps that will get
close to 100 cm2, and adjust the volume of water used to the equivalent of 2 mL for every 1 cm2 of
actual surface area of the cap used. Boil for 5 minutes and rinse five times with purified water or cold
water for injection.
Put the washed caps in a Type I glass vial with broad neck, add the same amount of purified water or
water for injection initially added to the caps and weigh. Cover the vial mouth with a Type I glass
beaker. Sterilize in an autoclave, so that the temperature of (121 ± 2) °C is reached within 20 to 30
minutes, and maintain this temperature for 30 minutes. Let it cool until reaching room temperature
for a period of approximately 30 minutes. Add purified water or water for injection to return to the
original mass. Shake, immediately decant and collect the liquid. This liquid must be stirred before
being used in each of the tests.
Blank preparation: The blank preparation must be conducted in a similar manner, using 200 mL of
purified water, or water for injection, omitting the caps.
Determination of turbidity. The determination of turbidity can be made through visual comparison
(Procedure A) or instrumentally, using an adequate turbidimeter (Procedure B). The instrumental
assessment of turbidity provides a test that does not depend on the visual acuity of the analysts.
Hydrazine sulfate solution. 1.0 g of hydrazine sulfate in water and dilute with water to 100.0 mL.
Allow to stand for four to six hours.
Opalescence stock suspension. Transfer 25.0 mL of the hydrazine sulfate solution to the
hexamethylenetetramine solution in the vial, mix and allow to stand for 24 hours. This suspension is
stable for two months, if stored in a glass container free from surface defects. The suspension must
not adhere to the glass and must be mixed before use.
Reference suspensions. Prepare according to Table 2. Mix and shake before use. Stable suspensions
of formazin that may be used to prepare stable standards are commercially available and can be used
after comparison with standards prepared as described.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RC6.2-00
Procedure A. Visual comparison – Use identical test tubes, in colorless glass; clear and neutral; with
a flat base and an internal diameter of 15 mm to 25 mm. Fill a tube with 40 mm of length with the
Preparation S, a tube of the same length with water, and four other tubes of the same length with the
Reference Suspensions A, B, C and D. Compare the preparations in diffuse daylight five minutes
after the preparation of the Reference suspensions, viewing, vertically, against a black background.
The light conditions must be such that the Reference suspension A can be readily distinguished from
water and that the Reference suspension B can be readily distinguished from the Reference suspension
A. Limit. The Preparation S must not be more opalescent than Reference suspension B for Type I
caps, and no more opalescent than the Reference suspension C for Type II caps. The Preparation S
is considered clear if the clarity is the same as the water when examined as described above, or if its
opalescence is not more pronounced than the one from Reference suspension A (refer to Table 3).
Determination of color
Standard color. Prepare a dilution of 3.0 mL of Matching Fluid O with 97.0 mL of diluted
hydrochloric acid.
Procedure. Use identical tubes, in neutral, colorless, clear glass, with flat bottom and internal
diameter of 15 to 25 mm. Put in a tube the Preparation S, forming a liquid column of 40 mm of length
and, in a second tube, the Color standard forming the same liquid column. Compare the liquids in
diffuse daylight, viewing, vertically, against a white backdrop.
Limit. The Preparation S must not be more intensely colored than the Color Standard.
Acidity or alkalinity
Procedure. Add 0.1 of the bromothymol blue solution to 20 mL of Preparation S. If the preparation
turns yellow, titrate with 0.01 M sodium hydroxide until the blue endpoint is reached. If the
preparation turns blue, titrate with hydrochloric acid 0.01 M until the yellow endpoint is reached. If
the preparation turns green, it is neutral and the titration is not necessary.
Correction of blank. Test 20 mL of blank in a similar manner. Correct the results obtained for
Preparation S through subtraction or addition of the volume of titrant required for the blank, as
appropriate.
Limit. No more than 0.3 mL of 0.01 M sodium hydroxide produces a blue color, or no more than
0.8 mL of 0.01 M hydrochloric acid produces a yellow color, or the titration is not necessary.
Absorbance
Procedure. Conduct this test in the time period of five hours after developing the Preparation S. Filter
the Preparation S through a filter with pore of 0.45 μm, discarding the first mL of the filtrate. Measure the
absorbance of the filtrate in wavelengths between 220 and 360 nm on a well with 1 cm using the blank in a
matching cell in a reference beam. If the filtrate dilution is necessary before measuring the absorbance, correct
the results from the test for dilution.
Limit. The absorbances in all these wavelengths must not exceed 0.2 for Type I caps or 4.0 for Type
II caps.
Reducing substances
Procedure. Conduct this test in the time period of four hours after developing the Preparation S.
Transfer to 20.0 mL of Preparation S 1 mL of diluted sulfuric acid and 20.0 mL of potassium permanganate
0.002 M. Boil for three minutes. Cool down, add 1 g of potassium iodide and titrate, immediately, with sodium
thiosulfate 0.01 M, using 25.0 mL of starch solution TS as indicator. Titrate using 20.0 mL of blank and notice
the difference in the volume of sodium thiosulfate 0.01 M necessary.
Limit. The difference between the titration volumes must not be higher than 3.0 mL for Type I caps
and must not be higher than 7.0 mL for Type II caps.
Heavy metals
Procedure. Proceed as guided for Method 1 in Heavy Metals. Use 10.0 mL of Preparation S in the
problem preparation.
Extractable Zinc.
Sample solution. Prepare a Sample solution through dilution of 10.0 mL of Preparation S to 100 mL
with hydrochloric acid 0.1 M. Prepare the test blank in a similar manner, using the blank for
Preparation S.
Zinc standard solution. Prepare a solution (10 ppm of Zn) dissolving zinc sulfate in hydrochloric
acid 0.1 M.
Reference solutions. Prepare no less than three Reference solutions through dilution of the Standard
zinc solution with hydrochloric acid 0.1 M. The concentrations of zinc in these Reference solutions
are the extension of the limit expected from the Sample solution.
Procedure. Use an atomic absorption spectrometer, adequate and equipped with an adequate source
of electromagnetic radiation and air acetylene flame. An alternative procedure, such as an analysis by
mass spectrometry or optical emission spectrometry with inductively coupled plasma, appropriately
validated, may be used.
Assess each one of the Reference solutions in wavelength for Zinc selected in 213.9 nm, no less than
three times. Register the stable readings. Rinse the equipment with the blank solution every time, to
ensure that the reading returns to the initial blank value. Prepare a calibration curve from the average
of readings obtained for each Reference solution. Register the absorbance of the Sample solution.
Determine the concentration of zinc in ppm of the Sample solution using the calibration curve.
Ammonium
Ammonium standard solution. Prepare an ammonium chloride solution in water (1 ppm of NH4).
Mix 10 mL of the solution of 1 ppm of ammonium chloride with 5 mL of water and 0.3 mL of alkaline
potassium tetraidomercurate (II) solution. Close the container.
Limit. After five minutes, any yellow color in the Sample solution must not be darker than in the
Standard ammonium solution (no more than 2 ppm of NH4 on Preparation S).
Volatile sulfides
Procedure. Put the caps, cut if necessary, with a total surface area of (20 ± 2) cm2 in a 100 mL vial,
and add 50 mL of a citric acid solution at 20 g/L. In the same manner and at the same time, prepare a
control solution in a separate 100 mL vial through dissolution of 0.154 mg of sodium sulfide in 50 mL
of a citric acid solution at 20 g/L. Put a piece of lead acetate paper on the mouth of each vial, and
hold the paper in position, placing an inverted weighing bottle over it. Heat the vials in autoclave at
(121 ± 2) °C for 30 minutes.
Limit. Any black coloring in the paper produced by Preparation S is not more intense than the one
produced by the control solution.
FUNCTIONAL TESTS
The samples treated as described for obtaining the Preparation S and air dried must be used for the
tests on functionality, penetrability, fragmentation and auto-sealing capacity. The functionality tests
are conducted on caps targeted at being penetrated by a hypodermic needle. The auto-sealing capacity
test is necessary only for caps targeted at multiple-dose containers. The needle specified for each test
is a lubricated hypodermic needle with long bevel (bevel angle 12 ± 2°) 1. 0F
Penetrability
Procedure. Fill 10 vials adequate to the nominal volume with water, adjust the caps to be examined,
and close the vials with the respective caps. Using a new hypodermic needle, as already described,
perforate the cap with the needle perpendicular to the surface.
Limit. The force for perforating each cap must not be greater than 10 N (1 kgf), determined with
precision of ± 0.25 N (25 gf).
Fragmentation
Caps for liquid preparations. Fill 12 clean vials with water until 4 mL less than the nominal capacity.
Adjust the caps to be examined, close with a lid and allow to stand for 16 hours.
Caps for dry preparations. Adjust the caps to be examined in 12 clean vials and close each one with
a lid.
Procedure. Using a hypodermic needle as previously described, adjusted to a clean needle, inject
inside each vial 1 mL of water, while removing 1 mL of air. Repeat this procedure four times for each
cap, perforate each time at a different place. Use a new needle for each cap, checking if its tip is not
blunt during the test. Filter the total volume of the liquid in all vials through a simple filter with
nominal pore size not larger than 0.5 μm. Count the rubber fragments on the filter surface that are
visible to the naked eye.
Limit. There are no more than five visible fragments. This limit is based on the assumption that
fragments with diameter superior to 50 μm are visible to the naked eye. In case of doubt or
controversy, the particles are examined microscopically to check their natures and sizes.
Auto-sealing capacity
Procedure. Fill 10 adequate vials with water up to the nominal volume. Adjust the caps to be
examined and cover. Using a new hypodermic needle like before for each cap, perforate each cap 10
times, every time at a different place. Immerse the 10 vials in a methylene blue solution 0.1% (1 g/L)
and reduce the external pressure by 27 kPa for 10 minutes. Restore atmospheric pressure and let the
vials immersed for 30 minutes. Rinse the external part of the vials.
Limit. None of the vials must have any trace of blue solution.
to light by inclusion of an opaque compound, is free from the requirements of item Light transmission
tests (6.2.3.4). The way it is used in this chapter, the term “container” refers to the full system
encompassing the container itself, the container when used, the closure in the case of multiple-unit
containers, and caps and blister in the cases of single-dose containers.
Procedure. Select 12 containers of uniform sizes and type, clean the closing surfaces with a fiber-
free cloth, close and open each container 30 times. Cover tightly and uniformly every time the
container is closed. Close the containers with a threaded cap with a torque movement that is within
the range specified on Table 1. Transfer desiccants to 10 containers, designated as test containers,
fill each one to 13 mm of the closure if the volume is 20 mL or higher, or fill each one to two thirds
of the capacity if the container volume is below 20 mL. If the internal part of the container has more
than 63 mm of depth, an inert funnel or spacer must be placed on the bottom to minimize the total
weight of the container and the desiccant; the layer of desiccant in such container must not be inferior
to 5 cm in depth. Close each one immediately after adding the desiccant, applying the torque
designated on Table 1 in the case of containers with screw cap. For each of the two remaining
containers, designated as controls, transfer a sufficient number of glass beads to achieve an
approximately equal weight to the one of test containers and close applying the torque designated on
Table 1 in the case of containers with screw cap. Register the weight of the containers, individually,
thus prepared to the approximation of 0.1 mg if the volume of the container is below 20 mL, or to the
approximation in closer mg if the container volume is 20 to 200 mL, or to approximation in
centigrams (10 mg) if the volume is 200 mL or higher. Store at relative humidity of (75 ± 3)% and at
temperature of (23 ± 2) °C. A saturated system of 35 g of sodium chloride for every 100 mL of water
placed on the bottom of the desiccator maintains the specified humidity, or other methods can be used
to maintain such conditions. After (336 ± 1) hours (14 days), register the weight of containers
individually, in the same manner. Completely fill five empty containers of the same size and type as
the test containers with water or a non-compressible, free-flow solid, such as properly accommodated
glass beads, to the level indicated by the closure surface. Transfer the content from each container to
a graded cylinder and determine the average volume of the container in mL. Calculate the humidity
permeability rate, in mg per day, per L, through the formula:
where
V is the volume in mL of the container,
(𝑇𝐹 − 𝑇𝐼) is the difference in mg between the final and initial weights of each test container;
(𝐶𝐹 − 𝐶𝐼) is the difference in mg between the final and initial average weights from the two controls.
For containers used in medicines dispensed with prescription, the containers thus tested are of the
sealed type, if no more than one of the 10 test containers exceeds 100 mg per day per L in humidity
permeability, and none exceeds 200 mg per day per L. For containers used for used for medicines
dispensed with prescription, the containers are tightly closed if no more than one of the 10 test
containers exceeds 2000 mg per day per L in humidity permeability and none exceeds 3000 mg per
day per L.
Polypropylene containers. Close the containers, with impenetrable seals obtained by hot sealing
with a polyethylene-laminated aluminum foil or another adequate closure. Test the containers as
described above. The containers comply with the requisites if the permeability to humidity exceeds
15 mg per day per L, at maximum, in 1 of the 10 test containers and does not exceed 25 mg per day
per L in none of them.
Desiccant. Dry the appropriate desiccant pellets at 110 °C for one hour before use. Use pellets with
approximate weight of 400 mg each one and with diameter of approximately 8 mm. If necessary, due
to the limited dimension of the unit-dose container, pellets weighing less than 400 mg each and with
diameter smaller than 8 mm can be used.
PROCEDURE
Method I. Seal no less than 10 unit-dose containers with one pellet each, and seal another 10 empty
unit-dose containers for control, using glove fingers or a padded tweezer to handle the sealed
containers. Number the containers and register the weights, individually, with the closest
approximation in mg. Weigh the controls as one unit and divide the total weight by the number of
controls to obtain the average. Store all containers at relative humidity of (75 ± 3)% and at
temperature of (23 ± 2) °C. A saturated system of 35 g of sodium chloride for every 100 mL of water
placed on the bottom of a desiccator maintains the specified humidity, or other methods can be used
to maintain such conditions. After an interval of 24 hours, and in each of their multiples, remove the
containers from the chamber and let them equilibrate for 15 to 60 minutes in the weighing area.
Register again the weight of the containers individually and the matched controls in the same manner.
If no indicator pellet turns pink during the procedures, or if the pellet weight increase exceeds 10%,
finish the test and consider only the first determinations as valid. Return the containers to the humidity
chamber. Calculate the humidity penetration rate in my per day from each container using the
formula:
where
N is the number of days expired in the test period (starting after the initial 24 hours of the equilibration
period);
(𝑊𝐹 − 𝑊𝐼) is the difference in mg between the final and initial weights of each test container;
(𝐶𝐹 − 𝐶𝐼) is the difference in mg between the final and initial average weights of the controls, with
the data calculated in relation to two significant figures. When the penetration measured is lower than
5 mg per day, and when it is observed that the controls reach equilibration in a period of seven days,
the individual penetration can be determined more precisely, using the test container from the 7th day
and the control container as WI and CI, respectively, in the calculations. In this case, an adequate test
interval for Class A must not be inferior to 28 days from the equilibration period of the 7th day (a total
of 35 days).
Method II. Use this procedure for packages, such as punch-out cards, that incorporate a number of
blisters or unit-dose containers sealed separately. Seal a sufficient number of packages, no less than
4, and a total of no less than 10 unit-dose containers or blisters filled with one pellet in each unit to
be tested. Seal a corresponding number of empty packages, each one containing the same number of
unit-dose containers or blisters like the ones used in test packages, as controls. Store all containers at
relative humidity of (75 ± 3)% and at temperature of (23 ± 2) °C. A saturated system of 35 g of sodium
chloride for every 100 mL of water placed on the bottom of the desiccator maintains the humidity
required, or other methods can be used to maintain such conditions. After 24 hours and at each
subsequent 24 hours, remove the packages from the chamber and let them equilibrate at room
temperature for approximately 45 minutes. Register the weights of individual packages and return
them to the chamber. Weigh the control packages as one unit and divide as one unit and divide the
total weight by the number of control packages to obtain the average weight of empty packages. If
any indicator pellet turns pink during the procedure, or if the average pellet weigh exceeds 10% in
any of the packages, finish the test and consider only the first determinations as valid. Calculate the
average humidity penetration rate, in mg per day, for each unit-dose container or blister, in each
package according to the formula:
where
N is the number of days elapsed in the test period (starting after the initial 24 hours of the equilibration
period);
X is the number of units sealed separately per package;
(WF – WI) is the difference in mg between the final and initial weights of each test package;
(CF – CI) is the difference in mg between the final and initial average weights of control packages, and
these rates are calculated up to two significant figures.
Limits. Individual unit-dose containers, as tested on Method I, are classified as Class A if no more
than 1 of the 10 containers tested exceeds 0.5 mg per day in humidity penetration rate and none
exceeds 1 mg per day; they are classified as Class B if no more than 1 of the 10 containers tested
exceeds 5 mg per day and none exceeds 10 mg per day; they are classified as Class C if no more than
1 of the 10 containers tested exceeds 20 mg per day and none exceeds 40 mg per day; and they are
classified as Class D if the containers tested do not meet any of these requisites for humidity
penetration rate.
The packages, as they are tested on Method II, are classified as Class A if no package tested exceeds
0.5 mg per day of average humidity penetration rate per blister; they are classified as Class B if no
package tested exceeds 5 mg per day of average humidity penetration rate per blister; they are
classified as Class C if no package tested exceeds 20 mg per day of average humidity penetration rate
per blister; and they are classified as Class D if no package tested meets the aforementioned requisites
for average humidity penetration rate per blister.
With the use of desiccant described on Method I and Method II, after every 24 hours, the test
containers and controls are weighed; the adequate test intervals for final weighing, WF and CF, must
be: 24 hours for Class D; 48 hours for Class C; 7 days for Class B; and no less than 28 days for Class
A.
weights and fill weights, at an approximation of 0.1 mg if the maximum capacity is lower than 200
mL; an approximation in mg if the maximum capacity is between 200 and 1000 mL; or an
approximation in centigrams (10 mg) if the maximum capacity is 1000 mL or higher.
Procedures for tests in commercialized closed containers (cap liner if applicable, internal sealing
and cap). Select 10 containers of uniform type and size and clean the sealing surfaces with a fiber-
free cloth. Assemble each container with the cap liner, if applicable, and closure system. Number
each closure system and register the tared weight.
Remove the closures and, with the help of a pipette, fill the containers to maximum capacity with
water. Assemble the container with the seals and apply the closures. If threaded caps are used, apply
the torque specified on Table 1 in Multiple-unit containers for capsules and tablets (6.2.3.1) and store
the closed containers at temperature of (25 ± 2) °C and relative humidity of (50 ± 2)%. After (168 ±
1) hours (seven days), register the weight of containers individually. Return the containers to the
storage place for another (168 ± 1) hours. After the second period of (168 ± 1) hours elapses, remove
the containers, register the weights of each container system, individually, and calculate the water
vapor penetration rate, in percentage of water weight loss, for each container through the formula:
The unit-dose containers for liquids comply with the requisites for a tightly sealed container if the
average weight in water weight loss is inferior or equal to 2.5% (w/w) per year and 5% at the end of
two years.
The containers thus tested comply with the requisites and are considered tightly sealed containers if
the percentage of water weight loss exceeds 2.5% per year, at maximum, in 1 of the 10 containers
tested and does not exceed 5.0% in none of them.
Procedure. Select sections to represent the average thickness of the container wall. Cut circular
sections from two or more areas of the container and trim if necessary to provide segments of
convenient sizes to be inserted in the spectrophotometer. Cut, wash and dry each sample, being careful
to avoid scratches in the surface. If the sample is too small to cover the opening on the sample support,
cover the uncovered portion of the opening with an opaque paper or adhesive tape, making the sample
length larger than the opening in the spectrophotometer. Immediately before assembling the sample
support, clean the sample with a cloth suitable for cleaning lenses. Assemble the sample with the help
of viscous wax, or through other convenient media, being careful to not leave fingerprints or other
marks on the surfaces the light must go through. Put the section in the spectrophotometer with its
cylindrical axis parallel to the opening plan and approximately centralized in relation to the opening.
When placed adequately, the light beam is normal at the section surface and the losses by reflection
are minimal. Measure, continuously, the section transmittance with reference to air in the wavelength
of interest, with a registration equipment or in intervals of approximately 20 nm with a manual
equipment, in the wave amplitude between 290 and 450 nm.
Limit. The light transmission observed must not exceed the limits included on Table 1 for containers
targeted at parenteral use.
Any container, with a size intermediate to the ones listed on Table 1, presents transmission not greater
than the next biggest size listed on the table. For containers larger than 50 mL, the limits for 50 mL
apply. The light transmission observed for plastic containers for products targeted at oral or topical
administration must not exceed 10% in any wavelength on the range between 290 nm and 450 nm.
6.2.4 BIOCOMPATIBILITY
In this section there are guidelines about procedures for assessment of biocompatibility of plastic
containers for medicines, elastomer caps and correlates. Biocompatibility refers to the trend of these
products to remain biologically inert when in contact with the body. In combination with chemical
assays, the biological processes can be used to detect and identify the inherent or acquired toxicity of
correlates, before or during their manufacturing and processing.
The procedures used to assess the biocompatibility of a correlate or its constituents were classified in
a panel of biological effects or toxicity procedures, such as cytotoxicity, sensitivity, irritation or
intracutaneous reactiveness, acute systemic toxicity, sub-chronic toxicity (sub-acute toxicity),
genotoxicity, implantation, hemocompatibility, chronic toxicity (extends by 10% the life expectancy
of the test animal, or to more than 90 days), carcinogenicity, reproductivity or development toxicity,
and biodegradation.
Pyrogenicity, in a special toxicity area, is assessed by the Bacterial endotoxins (5.5.2.2) test and the
Pyrogens (5.5.2.1) test. Currently, there are no chapters detailing about sensitivity, sub-chronic
toxicity, genotoxicity, chronic toxicity, carcinogenicity, hemotoxicity, reproductive toxicity, or
requisites for biodegradation test.
Contrary to plastics or other polymers, an elastomeric material that does not meet the requirements
from the first phase of the test in vitro can be considered a biocompatible material if it is approved on
the second phase – in vivo, which consists on the systemic injection test and the intracutaneous test
in Biological reactivity tests in vitro (6.2.5). No distinction of class or type is made between the
elastomeric materials that meet the requisites from the first phase of test and the ones that meet the
second phase, qualifying as biocompatible materials. Elastomeric materials are not classified on
classes I-VI.
6.2.4.2 CORRELATES
The biocompatibility of plastic, other polymers and elastomeric parts of these products is tested
according to the procedures described in Biological reactivity tests in vitro (6.2.5). If a class
designation is also necessary for a plastic or another polymer, the adequate test procedures described
in Biological reactivity tests in vivo (6.2.6) are conducted.
materials may depend both on their surface characteristics and their extractable chemical components.
The test procedures can be conducted with the material, or an extract of the material being tested,
except if indicated otherwise.
Preparation of extracts
Usually, the assessment of compatibility of an entire correlate is not realistic, and using representative
portions, or extracts from selected materials, may be a practical alternative for conducting the assays.
When portions or extracts are used, it is important to consider that the raw material may suffer
chemical changes during the manufacturing, processing and sterilization of a correlate. Assays in
vitro of a raw material may serve as an important triage process, but the final assessment of
biocompatibility of the correlate must be conducted with parts of the product, finished and sterilized.
The extractions can be made in several temperatures (121, 70, 50 or 37 °C), in several time intervals
(1, 24 or 72 hours) and in different extraction media. The selection of extraction medium for tests in
vitro includes sodium chloride solution injectable 0.9%, or culture medium for tissues with or without
serum. When medium with serum is used, the extraction temperature cannot exceed 37 °C. When
selecting the extraction conditions, select the temperature, solvent and time variables the best
conditions of use of the product. The performance from several tests in different conditions can be
used to simulate variations of the conditions “in use”. A biocompatibility assessment is conducted
with the product, finished and sterilized, although a careful selection of the extraction conditions
allows to simulate the raw material production and test conditions.
Test in vitro
When tests in vitro are conducted, the sample is biocompatible if the cell cultures do not present
reactivity greater than mild (grade 2), as described on the Biological reactivity tests in vitro (6.2.5).
According to the definition of injection and implantation described in Biological reactivity tests in
vivo (6.2.6), plastics and other polymers are classified in classes I to VI. To obtain designation of
plastics, or other polymers, extracts from the test substance are produced according to the procedures described
in different media. To assess the biocompatibility, the extracts are inoculated, systemically and
intracutaneously, in mice and rabbits. According to the requisites for injection, a plastic or other polymer can
be initially classified as I, II, III, or V. If, in addition to the injection test, the implantation test is conducted
with the same material, the plastic or polymer can be classified as class IV or VI.
In international guidelines, there is an indication that the extension of tests executed for a correlate
depends on the following factors: product similarity and exclusivity in relation to products previously
commercialized, as considered on the Decision flowchart; extension and duration of contact between
the product and the patient, as described in Categorization of correlates, and the composition of the
product material, as considered in the sections Decision flowchart, Tests in vivo and Class
designation.
DECISION FLOWCHART
The guidance for comparing a correlated with products commercialized previously is provided by the
Biocompatibility decision flowchart (Figure 1).
Start
Does the
correlate come No
into direct or
indirect contact
with the body?
Yes
Is the existing
material the same Yes Is the Yes Is the sterilization
one as a Is the chemical Yes Is the form of contact Yes Yes
manufacturin composition the with the body similar? method similar?
commercialized
correlate? g process the same?
same? No No
No
No No
No Acceptable Yes
justification or
assay data?
Does it have
Is the material any toxic
Is the correlate No Yes substance, No
material a polymer? a metal,
metallic alloy such as Pb,
or ceramic Ni, Cd, Zn,
alloy? etc.?
Yes Yes
No
Consult on the specific
toxicologic profile of
the correlate for No Acceptable Yes
adequate assays. justification or
assay data?
No
Toxic material
Figure 1 – Biocompatibility flowchart adapted from the FDA Blue Book Memorandum # G95-1.
The goal with the flowchart is to determine whether the data available on previously commercialized
correlates are sufficient to ensure the safety of the correlate in question. As indicated on the flowchart,
the material composition and manufacturing techniques of a product are compared with correlates
already commercialized that come into direct contact with the body. Additionally, there is a
requirement on the flowchart for an assessment of the toxicity of an exclusive material that has not
been previously used in correlate products. The answers to the questions made on the flowchart lead
to the conclusion that the data available are sufficient, or that additional tests are necessary to ensure
the product safety. The guidance about the identification of appropriate procedures for additional tests
is provided in the Test selection matrix.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RC6.2-00
CATEGORIZATION OF CORRELATES
To facilitate the identification of adequate test procedures, the correlates are divided and subdivided,
as registered on Table 1, according to the nature and extension of their contact with the body. The
main categories of correlates are surface, extracorporeal communication and implantable. Then, these
classifications are subcategorized with examples of correlates belonging to each of the subcategories
(Table 1).
In the matrix there is guidance for identification of adequate procedure for biological assays for the
three categories of correlates: Tests for surface devices (Table 1 in Guide for selection of plastic and
other polymers (6.2.4.5)), Tests for extracorporeal communication devices (Table 2 in Guide for
selection of plastic and other polymers (6.2.4.5)), and Tests for implantable devices (Table 3 in Guide
for selection of plastic and other polymers (6.2.4.5)). Each category of correlates is subcategorized
and subdivided according to the duration of contact between the device and the body. The duration
of contact is defined as limited (less than 24 hours); prolonged (24 hours to 30 days), or permanent
(more than 30 days). The biological effects included in the matrix are: cytotoxicity, sensitivity,
intracutaneous irritation or reactivity, systemic toxicity, sub-chronic toxicity, genotoxicity,
implantation, hemocompatibility, chronic toxicity, carcinogenicity, reproductive or development
toxicity, and biodegradation. In the matrix, for each subcategory there is a board associated to the test
requisites and, usually, the number of tests increases as the duration of the contact between the device
and the body is extended and according to the proximity of contact between the device and the
circulatory system. In the subcategories, the option of conducting additional tests must be considered
on a case-by-case basis. Specific situations, such as the use of permanent implantable devices or with
extracorporeal communication in pregnant women, must be considered by the manufacturer, who will
decide about including the reproduction or development test. Guidance about identifying eventual
additional procedures for test is provided in the matrix of each subcategory of correlates.
In Figure 1 there is guidance for selecting the appropriate class designation of the plastic or other
polymer for a correlate and each subcategory of Surface devices, and on Figure 2, for Communication
devices. The class designations can be found on Biological reactivity tests in vivo (6.2.6).
Surface Device
Broken or
Skin Surfaces of Compromised
Mucosas Surfaces
Figure 1 – Class Requisites of plastics and other polymers for surface devices.
__________
* Categorization based on the duration of contact. Limited: less than 24 hours; prolonged: 24 hours to 30 days; permanent: more than 30 days.
† Designation of Class of Plastics.
Extracorporeal
Communication
Device
Figure 2 – Class Requisites of plastics and other polymers for extracorporeal communication devices.
__________
* Categorization based on the duration of contact. Limited: less than 24 hours; prolonged: 24 hours to 30 days; permanent: more than 30 days.
† Designation of Class of Plastics.
The class number indicated increases according the duration of contact between the device and the
body (risk). In the category of Implantable devices, the exclusive use of class VI is mandatory. The
designation of plastic classes is based on the test selection matrixes illustrated on Tables 1, 2 and 3.
The assignment of class of a plastic or another polymer to a subcategory is not targeted at restricting
the use of superior categories of plastics or other polymers. Although the designation assigned defines
the lower numerical class of plastic or other polymer that can be used in the corresponding correlate,
the use of a numerically higher plastic class is optional. When a correlate belongs to more than one
category, the plastic or other polymers must meet the requirements from the higher numerical class.
Intracutaneous irritation
Sub-chronic (sub-acute)
Duration of contact a
development toxicity
Hemocompatibility
Systemic toxicity
Chronic toxicity
Reproductive or
Carcinogenicity
Biodegradation
Implantation
Genotoxicity
or reactivity
Cytotoxicity
Sensitivity
(acute)
toxicity
Contact with the body
Skin A X X X - - - - - - - - -
B X X X - - - - - - - - -
C X X X - - - - - - - - -
Mucosa A X X X - - - - - - - - -
Surface devices B X X X O O - O - - - - -
C X X X O X X O - O - - -
Compromised or A X X X O - - - - - - - -
breached surfaces
B X X X O O - O - - - - -
C X X X O X X O - O - - -
__________
a Key A: limited (less than 24 hours); B: prolonged (24 hours to 30 days); C: permanent (more than 30 days).
b Key X: ISO assessment tests for consideration; O: additional tests that may be applied.
* Adapted from FDA’s Blue Book Memorandum #G95-1 (Table 1. Initial Assessment tests for Consideration and Table 2. Complementary Assessment Tests for Consideration).
Intracutaneous irritation
Sub-chronic (sub-acute)
Duration of contact a
development toxicity
Hemocompatibility
Systemic toxicity
Chronic toxicity
Reproductive or
Carcinogenicity
Biodegradation
Implantation
Genotoxicity
or reactivity
Cytotoxicity
Sensitivity
(acute)
toxicity
Contact with the body
Blood vessel, A X X X X - - - X - - - -
indirect
B X X X X O - - X - - - -
C X X O X X X O X X X - -
Extracorporeal Communication A X X X O - - - - - - - -
communication with tissue, bone or
device dentin B X X O O O X X - - - - -
C X X O O O X X - X X - -
Blood circulation A X X X X - O - X - - - -
B X X X X O X O X - - - -
C X X X X X X O X X X - -
__________
a Key A: limited (less than 24 hours); B: prolonged (24 hours to 30 days); C: permanent (more than 30 days).
b Key X: ISO assessment tests for consideration; O: additional tests that may be applied.
* Adapted from FDA’s Blue Book Memorandum #G95-1 (Table 1. Initial Assessment tests for Consideration and Table 2. Complementary Assessment Tests for Consideration).
Intracutaneous irritation
Sub-chronic (sub-acute)
Duration of contact a
development toxicity
Hemocompatibility
Systemic toxicity
Chronic toxicity
Reproductive or
Carcinogenicity
Biodegradation
Implantation
Genotoxicity
or reactivity
Cytotoxicity
Sensitivity
(acute)
toxicity
Contact with the body
Tissue or bone A X X X O - - - - - - - -
B X X O O O X X - - - - -
Implantable devices C X X O O O X X - X X - -
Blood A X X X X - - X X - - - -
B X X X X O X X X - - - -
C X X X X X X X X X X - -
__________
a Key A: limited (less than 24 hours); B: prolonged (24 hours to 30 days); C: permanent (more than 30 days).
b Key X: ISO assessment tests for consideration; O: additional tests that may be applied.
* Adapted from FDA’s Blue Book Memorandum #G95-1 (Table 1. Initial Assessment tests for Consideration and Table 2. Complementary Assessment Tests for Consideration).
1 Document from ISO 10993-1:1997 titled Biological Evaluation of Medical Devices – Part 1: Evaluation and Testing .
* Adapted from FDA’s Blue Book Memorandum #G95-1 (“Use of International Standard ISO-10993.” Biological Evaluation of Medical Devices - Part 1: Evaluation and Testing.’” )
Three assays are described: Agar diffusion test, Direct contact test and Elution test. The decision on
what type or the number of assays to be conducted to assess the potential of biological response from
a specific sample or an extract depends on the material, the end product, and its intentions of use.
Other factors that may also affect the suitability of the sample for a specific use are: polymer
composition; procedures for processing and cleaning; means of contact; colorants; adhesives;
absorption, adsorption and permeability of preservatives; and storage conditions. Such factors must
be assessed by specific appropriate additional assays, before determining that a product produced
through a specific material is adequate for its intention of use.
Preparation of cell culture. In a minimum essential medium supplemented with seeding density
serum of approximately 105 cells per mL, prepare multiple cultures of fibroblastic cells L-929 (ATCC
cell line CCL 1, NCTC clone 929). Incubate the cultures at (37 ± 1) °C in a humidified incubator,
with atmosphere of (5 ± 1)% carbon dioxide, for no less than 24 hours until obtaining the single layer,
with confluence superior to 80%. Examine the cultures prepared with a microscope to ensure an
uniform level of nearly confluent monolayers.
Extraction solvents. Injectable sodium chloride solution (refer to the corresponding monograph).
Alternative, free media or supplemented with serum for mammal cell culture can be used. The serum
supplementation is used when the extraction is performed at 37 °C, for 24 hours.
Equipment
Autoclave. Use an autoclave capable of maintaining the temperature of (121 ± 2) °C and capable of
cooling the assay containers down around 20 °C.
Oven. Preferably use a model with mechanic convection, capable of maintaining the operating
temperatures in the range of 50 °C to 70 °C ± 2 °C.
Incubator. Use an incubator capable of maintaining the temperature of (37 ± 1) °C and a humid
atmosphere with (5 ± 1)% carbon dioxide in the air.
Extraction containers. Use only Type I glass containers, such as culture test tube with screw cap, or
equivalent. The screw cap must have appropriate elastomeric coating. The exposed surface of this
coating must be completely protected with an inert solid disc of 50-75 μm of thickness.
Preparation of equipment. Completely clean all glassware with chromic acid cleaning solution and,
if necessary, with warm nitric acid, followed by prolonged rinsing with sterile water for injection.
Sterilize and dry the containers and equipment used for extraction, transfer or administration of the
assay material, through adequate process. If ethylene oxide is used as a sterilizing agent, wait no less
than 48 hours until complete degassing.
Procedure
Preparation of sample for extract. Prepare as described in the Procedure from Biological reactivity
tests in vivo (6.2.6).
Preparation of extracts. Prepare as described in the Procedure from Biological reactivity tests in vivo
(6.2.6), using an injectable sodium chloride solution (0.9% NaCl) or serum-free medium for mammal
cell culture as described in Extraction solvents. If the extraction is made at 37 °C for 24 hours in
incubator, use cell culture media supplemented with serum. In no case must the extraction conditions
cause physical changes, such as fusion or melting of portions of material, except a slight adherence.
This test was developed for elastomeric materials of different models. The agar layer works as a
support to protect the cells from mechanical damages, allowing the diffusion of leachable chemical
products from polymeric samples. The extracts from materials to be tested are applied to a piece of
filter paper.
Sample preparation. Use extracts prepared as described or portions of samples with flat surfaces not
inferior to 100 mm2.
Procedure. Use 7 mL of the cell suspension prepared as described in the Preparation of cell culture
and prepare the layers on plates with 60 mm of diameter. After the incubation is done, aspirate the
culture medium from the layers and replace it with medium supplemented with serum with amounts
of up to 2% of agar. The quality of agar must be adequate to sustain the cell growth. The agar layer
must be sufficiently thin to allow the diffusion of leachable chemical products. Put the flat surfaces
of the sample, negative control and positive control, or their extracts, in contact with the solidified
surface of agar, in duplicate. Do not use more than three samples in each plate prepared. Incubate all
cultures at (37 ± 1) °C for no less than 24 hours, in an adequate incubator. Examine, visually or with
a microscope, each culture around the sample; negative control and positive control, using adequate
coloring agent, if necessary.
Interpretation of results. The biological reactivity, that is, the cell malformation and degeneration,
is described and classified on a scale from 0 to 4 (Table 1). Measure the responses of cell cultures
from the sample, negative control and positive control. The cell culture assay system is adequate if
the responses observed are classified as 0 (no reactivity) for negative control and no less than 3
(moderate) for positive control. The sample complies with the test requisites if the response is not
superior to the classification 2 (mildly reactive). Repeat the procedure if the system suitability is not
confirmed.
Table 1 – Classification of reactivity for Agar diffusion test and Direct contact test.
Classification Reactivity Description of reactivity zone
0 None No zone detectable around or under the sample.
1 Slight Some malformed or degenerated cells under the sample.
2 Mild Zone limited to the area under the sample.
3 Moderate Zone extends from 0.5 to 1.0 cm beyond the sample.
4 Strong Zone extends more than 1.0 cm beyond the sample.
This test is defined for materials in different formats. The procedure allows simultaneous extractions
and test on leachable chemical products from the sample in a medium supplemented with serum. The
procedure is not appropriate for materials with very high or very low density, because it may cause
mechanical damages to the cells.
Sample preparation. Use a portion of sample with flat surface not inferior to 100 mm2.
Procedure. Use 2 mL of the cell suspension prepared as described in Preparation of cell culture and
prepare the layers on plates with 35 mm of diameter. After the incubation, aspirate the culture medium
and replace it with 0.8 mL of fresh culture medium. Put a single sample, negative control and positive
control in each of the culture medium duplicates. Incubate all cultures at (37 ± 1) °C for no less than
24 hours in an adequate incubator. Examine, visually or with a microscope, each culture around the
sample, negative control and positive control, using adequate coloring agent, if necessary.
Interpretation of results. Proceed according to the interpretation of results from the Agar diffusion
test. The sample complies with the test requisites if the sample response is not superior to the
classification 2 (mildly reactive). Repeat the procedure if the system suitability is not confirmed.
ELUTION TEST
This assay is defined for assessment of extracts from polymeric materials. The procedure allows
extracting samples by varied time intervals and in physiological and non-physiological temperatures.
It is appropriate for high-density materials and dose-response assessments.
Procedure. Use 2 mL of the cell suspension prepared as described in the Preparation of cell culture
and prepare the monolayers on plates with 35 mm of diameter. After the incubation, aspirate the
medium from the layers and replace it with extract from the sample, negative control and positive
control. Extracts from media, supplemented or not with serum, are tested in duplicate, without dilution
(100%). The extract of injectable sodium chloride solution is diluted with cells from the culture
medium supplemented with serum and tested, in duplicate, at a concentration of 25%. Incubate all
cultures at (37 ± 1) °C for 48 hours, in an adequate incubator. Examine with a microscope each culture
after 48 hours, using adequate coloration, if necessary.
Interpretation of results. Proceed according to the interpretation of results from the Agar diffusion
test, but using Table 2. The sample complies with the test requisites if the sample response is not
superior to the classification 2 (mildly reactive). Repeat the procedure if the system suitability is not
confirmed. For dose-response assessments, repeat the procedure using quantitative dilutions of the
sample extract.
Three assays are described to classify plastics and other polymers, which are applicable to materials
and correlates, based on in vivo biological reactivity assays. The Systemic injection test and the
Intracutaneous test are used for elastomeric materials, especially for materials where the adequate
Biological reactivity test in vitro (6.2.5) indicated significant biological reactivity. The Implant test
is used to check the suitability of plastics and other polymers, used in manufacturing containers and
accessories; in parenteral preparations, in correlates, implants and other systems.
The following definitions are applied in this chapter: sample is the material being tested, or the extract
prepared from a certain material. The blank consists of the same amount of the medium that is used
for the sample extraction, being treated the same way than the medium that has the sample analyzed.
The negative control is a sample that does not present any reaction in the assay conditions.
Classification of plastics. Six classes of plastic are defined (Table 1), based on the responses for a
series of assays in vivo where the extracts, materials and routes of administration are specified. These
tests are directly related to the end use of plastic articles. In preparations where plastics are susceptible
to coming into contact with the vehicles, the selection of extraction solution is representative. The
classification registered on Table 1 summarizes the tests to be conducted in containers for injection
and in medical devices, if there is need for classification.
With exception of the Implantation test, the procedures are based on the use of extracts that, due to
the thermal resistance of the material, are prepared in one of the three standard temperatures: 50, 70
and 121 °C. For this reason, the class designation of a plastic must be followed by an indication of
the extraction temperature (for example: IV-121 °C is the designation of class IV, from a plastic
extracted at 121 °C; I-50 °C is the designation of class I, from a plastic extracted at 50 °C). Plastics
can be classified on classes I to VI, based on the response criteria registered on Table 1.
This classification does not apply to plastics that are used as containers for topical or oral products,
or that may be used as an integral part of a medicine formulation. The information registered on Table
1 does not apply to natural elastomers, which are only tested through injectable sodium chloride
solution and vegetable oils.
The Systemic injection test and the Intracutaneous test are developed to determine, respectively, the
systemic and local biological responses; in animals exposed to plastics and other polymers, by
inoculation of single dose of specific extracts of the sample. The Implantation test is developed to
assess the reaction of live tissue to plastic and other polymers, through implanting the own sample in
animal tissue. The adequate preparation and placement of the samples in asepsis conditions are
important for conducting the Implantation test.
These tests are developed for application in materials in the conditions they are used. If the material
must be exposed to any cleaning or sterilization process before its end use, the tests must be conducted
in a sample submitted to such processes.
Extraction media
Vegetable oil. Use sesame oil, cottonseed oil, or other appropriate vegetable oils (refer to the
monograph). If possible, obtain freshly refined oils. Use three animals duly prepared and inoculated
intracutaneously in each animal one dose of 0.2 mL of oil, in each of the 10 sites, and observe the
animals for 24, 48 and 72 hours after the inoculation. Classify the observations from each site,
according to the numeric scale indicated on Table 2. At any point of observation, the average response
on the three rabbits (30 inoculation sites) must not be superior to 0.5 for erythema, must be inferior
to 1.0 for edema, and in no site there can be a tissue reaction larger than 10 mm of total diameter. The
oil residue in the inoculation site must not be interpreted as edema. When softly pressed, the tissue
edema turns whitish.
Equipment
Autoclave. Use an autoclave capable of maintaining the temperature of (121 ± 2) °C and capable of
cooling the assay containers down around 20 °C.
Oven. Preferably use a model with mechanic convection, capable of maintaining the operating
temperatures in the range of 50 °C to 70 °C ± 2 °C.
Extraction containers. Use only Type I glass containers, such as culture test tube with screw cap, or
equivalent. The screw cap must have appropriate elastomeric coating. The exposed surface of this
coating must be completely protected with an inert solid disc of 50-75 μm of thickness.
Preparation of equipment. Completely clean all glassware with chromic acid cleaning solution and,
if necessary, with warm nitric acid, followed by prolonged rinsing with water. Before using in the
subdivision of sample, clean cutting equipment items with an adequate method, such as successive
cleanups with acetone and methylene chloride. Clean all other equipment items through complete
washing with adequate detergent and prolonged rinsing with water. Sterilize and dry the containers
and equipment used for extraction, transfer or administration of the assay material, through adequate
process. If ethylene oxide is used as a sterilizing agent, allow an adequate time until complete
degassing.
Procedure.
Sample preparation. The Systemic injection test and the Intracutaneous test can be conducted with
the same extract or with different extracts. Select and subdivide the sample in parts with the size
indicated on Table 3. Remove the particulate material from each subdivided sample, or negative
control, putting the sample in a 100 mL type I glass graded cylinder, clean and with lid, and add
approximately 70 mL of water for injection. Shake for about 30 seconds and drain the water, repeat
this step and dry the parts prepared for extraction with oil in an oven up to 50 °C. Do not clean the
sample with dry or damp cloth or wash and rinse with organic solvent, surfactant, etc.
Preparation of extracts. Put a sample, duly prepared, to be tested in an extraction container and
transfer 20 mL of the adequate medium. Repeat these instructions for each extraction medium
necessary for the test. Also prepare a blank of 20 mL of each medium for parallel injections and
comparisons. Extract by heating, in an autoclave at 121 °C, for 60 minutes, and in case of an oven at
70 °C, for 24 hours, or at 50 °C for 72 hours. Allow sufficient time for the liquid in the container to
achieve the extraction temperature. In no moment must the extraction conditions cause physical
changes, such as fusion or melting of sample parts, to not result in a reduction of the surface available.
A slight adherence of the parts can be tolerated. Always transfer, individually, the clean parts to the
extraction medium. If the culture tubes are used for extracting vegetable oil with autoclave, properly
seal the thread caps with pressure-sensitive adhesive tape. Cool down to room temperature, but not
inferior to 20 °C, shake, vigorously, for several minutes, and immediately decant each extract
aseptically, in a sterile and dry container. Store the extracts at a temperature between 20 °C and 30
°C and do not use for tests after 24 hours.
This test is developed to assess the systemic responses to extracts from materials tested through
inoculation in mice.
Test animal. Use healthy albino mice, not used before, weighing between 17 and 23 g. For each test
group, use only mice from the same origin. Water and foods with known composition, commonly
used in laboratory animals, are freely permitted.
Procedure. Before taking the inoculation dose, shake vigorously each extract to ensure the even
distribution of the matter extracted. Visible particles must not be administered intravenously. In a test
group, inoculate in each of the five mice the sample or blank, as described on Table 4, diluting each
g of the extract of sample prepared with polyethylene glycol 400 and the corresponding blank, with
4.1 volumes of injectable sodium chloride solution, to obtain a solution with concentration of
approximately 200 mg of Macrogol per mL.
Observe the animals on the following times: immediately after inoculation, after four hours, and, at
minimum, after 24, 48 and 72 hours. If during the observation period none of the animals treated with
the extract of sample presents biological reactivity significantly higher than the ones treated with
blank, the sample complies with the requisites from this test. If two or more mice die or present
abnormal behavior, such as convulsions or prostration, or if there is loss of body weight superior to 2
g in three or more mice, the sample does not comply with the requisites from the test. If an animal
treated with the sample displays only slight signs of biological reactivity, and if only one animal
presents severe symptoms of biological reactivity or dies, repeat the test using groups of 10 mice. In
the repetition test, during the observation period, none of 10 animals treated with the sample must
present any significant biological reactivity more than the ones treated with blank.
INTRACUTANEOUS TEST
This test was developed to assess local responses to the extracts from materials tested, after
intracutaneous inoculation in rabbits.
Test animal. Select healthy albino rabbits, which hair can be tied close to the skin, which must be
thin and free from irritation or trauma. When handling animals during the observation periods, avoid
touching the inoculation sites, except for differentiating an edema and a residue of oil. Rabbits
previously used in independent tests, such as the pyrogen test (5.5.2.1), and which have rested during
the period expected can be used for this test, provided they have a clear, blemish-free skin.
Procedure. Before taking the inoculation dose, shake vigorously each extract, to ensure the even
distribution of the matter extracted. On the test day, carefully tie the hair on the animal’s back, on
both sides of the spine, over a sufficiently large test area. Avoid irritation and trauma. Remove loose
hair by vacuum. If necessary, before the inoculation, slightly clean the skin with diluted alcohol and
let it dry. More than one extract from a certain material can be used per rabbit, if it is determined that
the results will not be affected. For every sample, use two animals and inoculate intracutaneously,
using one side of the animal for the sample and the other for blank, as described on Table 5. Dilute
every g of the extract of sample prepared with polyethylene glycol 400 and the corresponding blank
with 7.4 volumes of injectable sodium chloride solution to obtain a solution with concentration of
approximately 120 mg of polyethylene glycol per mL.
Examine the inoculation sites to make evident any tissue reaction, such as erythema, edema and
necrosis. If necessary, slightly clean the skin with diluted alcohol to facilitate the reading of
inoculation sites. Observe all animals 24, 48 and 72 hours after the inoculation. Classify the
observations in a numeric scale for the extract sample and for the blank, using Table 2. If necessary,
tie the hair again during the observation period. The average score of erythema and edema for the
sample and blank sites is determined for each rabbit and each score interval after 24, 48 and 72 hours
of inoculation. After the score related to 72 hours, all scores from erythema, plus the ones from edema,
are totaled, separately, for each sample and blank. Divide each total by 12 (2 animals × 3 score periods
× 2 score categories) to determine the total average for each sample versus each corresponding blank.
The test requisites are complied with if the difference between the average score of the sample and
the blank is inferior or equal to 1.0. If in any observation period the average for the sample reaction
is questionable for being higher than the average for the blank reaction, repeat the test using three
additional rabbits. The test requisites are complied with if the difference between the average score
of the sample and the blank is equal or inferior to 1.0.
IMPLANT TEST
The implant test is developed to assess plastic materials and other polymers when they come into
direct contact with live tissue. The adequate preparation of the implant strips and their implantation
must be conducted under asepsis conditions. Prepare for implanting 8 strips of sample and 4 strips of
standard. Each strip must measure no less than 10 × 1 mm. The strip edges must be as soft as possible,
to avoid additional mechanical traumas in the implantation. The strips of minimum size specified are
implanted through a hypodermic needle (15 to 19 gauge) with intravenous tip and sterile trocar. Use
one or another pre-sterilized needle where the sterile plastic strips are inserted aseptically, or insert
each clean strip in a needle which cannula and central orifice are protected with an adequate cap, and
then submitted to the appropriate sterilization procedure.
Test animal. Select healthy adult rabbits with minimum weight of 2.5 kg, with sufficiently large
paravertebral muscles to allow the implantation of test strips. Do not use any muscle tissue in addition
to the one located in the paravertebral area. The animals must be anesthetized with an anesthetic agent
that is commonly used for a sufficient level of depth to prevent muscle movements, such as spasms.
Procedure. Conduct the test in a clean area. On the test day or up to 20 hours previously, tie the
animals’ hair on both sides of the spine. Remove loose hair with vacuum. Before the inoculation,
slightly clean the skin with diluted alcohol and dry it. Implant four strips of sample in paravertebral
muscles, spaced approximately 2.5 cm apart, in one side of the spine of each of the two rabbits, 2.5 cm
to 5.0 cm away from the medial line and parallel to the spine. Likewise, implant two strips of standard
on the opposite muscle of each animal. Insert a sterile catheter in the needle to hold the implant strip
on the tissue with the needle removal. After implanting one strip, if there is excessive bleeding, put
another piece in duplicate on another site. Keep the animals for a minimum period of 120 hours and
euthanize them at the end of the observation period with an overdose of anesthetic agent or other
adequate agents. Allow sufficient time to elapse to cut the tissue without bleeding. Examine
macroscopically the tissue area around the central part of every implant strip. Use magnifying glasses
and an additional source of light. Observe if there are hemorrhages, necroses, discolorations and
infections in the site of implantation of sample and control and register the observations. If there is
encapsulation, measure and register the capsule width, rounding to the closest 0.1 mm, from the
periphery of the space occupied by the control implant or sample to the periphery of the capsule.
Score the encapsulation, according to Table 6. Calculate the differences between the average score
for the sample and control sites. The test requisites are complied with if the difference is not superior
to 1, or if the difference for more than one of the four implant sites does not exceed 1 in any of the
animals.
7 REAGENTS
6B
Methyl orange TS
Xylenol orange
CAS – [3618-43-7].
Molecular formula and molar mass – C31H28N2Na4O13S – 760.59.
Description – Red-brown crystalline powder.
Solubility – Soluble in water and ethyl alcohol.
Xylenol orange TS
Preparation – Dissolve 0.1 g of xylenol orange in 100 mL of ethyl alcohol.
Change of color – Presents pale yellow color in acidic medium. Reacting with certain metals (such
as lead and zinc), forms a complex of intense red color. In presence of excess disodium edetate,
acquires a yellow color.
Alizarin
CAS – [130-22-3].
Molecular formula and molar mass – C14H7NaO7S.H2O – 360.27.
Description – Orange-yellow powder.
Solubility – Freely soluble in water and in ethyl alcohol.
Alizarin TS
Preparation – Dissolve 0.1 g of alizarin in 100 mL of water.
Alizarin yellow GG TS
Preparation – Dissolve 0.1 g of alizarin yellow GG in 100 mL of water.
pH range – 10.0 – 12.0.
Change of color – Provides pale yellow color in weakly alkaline solutions and brown color in strongly
alkaline solutions.
Solubility – Insoluble in water, soluble in ethyl alcohol, benzene, chloroform, ethyl ether, and diluted
mineral acids.
Dimethyl yellow TS
Preparation – Dissolve 0.2 g of dimethyl yellow in 100 mL of 90% (v/v) ethyl alcohol.
pH range – 2.8 – 4.6.
Change of color – Provides red color in moderately acidic solutions and yellow color in weakly acidic
and alkaline solutions.
Homogeneity test – Prepare 0.01% (w/v) dimethyl yellow solution in methylene chloride and apply
0.01 mL of this solution on silica-gel G TLC plate. Use methylene chloride as eluent. The
chromatogram must present a single stain.
Sensitivity test – Prepare a solution with 2 g of ammonium chloride in 25 mL of carbon dioxide-free
water. This solution, added with 0.1 mL of dimethyl yellow TS, must present a yellow color. The
color turns red by adding no more than 0.1 mL of hydrochloric acid 0.1 M.
Metanil yellow TS
Preparation – Dissolve 0.1 g of metanil yellow in 100 mL of methyl alcohol.
Change of color – In titrations developed in non-aqueous medium, it changes the color from yellow
(basic medium) to crimson (acidic medium).
Sensitivity test – Dissolve 0.1 mL of metanil yellow TS in 50 mL of glacial acetic acid. This solution
must present a pink-red color. Add 0,05 mL of perchloric acid 0.1 M. The color must change to violet.
Titan yellow TS
Preparation – Dissolve 0.05 g of titan yellow in water and complete the volume to 100 mL using the
same solvent.
pH range – 12.0 – 13.0.
Change of color – In acidic and moderately alkaline solutions, it provides yellow color. In strongly
alkaline solutions, it presents red color.
Sensitivity test – Prepare a mixture with 10 mL of water, 0.2 mL of standard magnesium solution (10
ppm Mg) and 10 mL of sodium hydroxide M. Add 0.1 mL of titan yellow TS. Prepare the blank test
in a similar manner, but omitting the magnesium standard. Compare the two solutions. An intense
rose color develops in comparison with the blank test.
Starch TS
Specification – 2% (w/v) soluble starch solution in hot water. The solution may present slight
opalescence.
Sensitivity test – Mix 1 mL of starch TS, 20 mL of water, approximately 50 mg of potassium iodide
and 0.05 mL of iodine 0.01 M. A blue color develops.
Iodized starch TS
Preparation – Weigh 0.5 g of starch, add 50 mL to 60 mL of water and dissolve by heating. Dissolve
0.5 g of potassium iodide in the solution and complete the volume to 100 mL with water. Protect from
light . Use within 24 hours after the preparation.
Iodide-free starch TS
Preparation – Crush 1 g of soluble starch with 5 mL of water and add, with constant agitation, water
in sufficient ebullition to complete 100 mL.
Stability – Prepare immediately before use.
Bromophenol blue
CAS – [115-39-9].
Molecular formula and molar mass – C19H10Br4O5S – 669.96.
Description – Light orange-yellow powder.
Solubility – Very slightly soluble in water, slightly soluble in ethyl alcohol, and freely soluble in
alkaline hydroxide solutions.
Bromophenol blue TS
Preparation – Dissolve, heating slowly, 0.2 g of bromophenol blue in 3 mL of 0.1 M sodium
hydroxide and 10 mL of ethyl alcohol. Let it cool down and complete the volume to 100 mL with
ethyl alcohol.
pH range – 2.8 – 4.6.
Change of color – Provides yellow color in moderately acidic solutions and violet-blue color in
weakly acidic and alkaline solutions.
Bromothymol blue
CAS – [76-59-5].
Molecular formula and molar mass – C27H28Br2O5S – 624.38.
Description – Brown or light red powder.
Solubility – Practically insoluble in water, soluble in ethyl alcohol and diluted alkali hydroxide
solutions.
Bromothymol blue TS
Preparation – Heat 1 g of bromothymol blue with 3.2 mL of 0.05 M sodium hydroxide and 5 mL of
ethyl alcohol. After dissolution, complete the volume to 250 mL with ethyl alcohol.
pH range – 6.0 – 7.0.
Change of color – Provides yellow color in weakly acidic solutions and blue color in weakly alkaline
solutions. In neutral medium, provides green color.
Sensitivity test – The mixture of 0.3 mL of bromothymol blue TS with 100 mL of carbon dioxide-free
water presents a yellow color. The color changes to blue with the addition of no more than 0.1 mL of
sodium hydroxide solution 0.02 M.
Hydroxynaphthol blue
CAS – [63451-35-4].
Molecular formula and molar mass – C20H11N2Na3O11S3 – 620.46.
Hydroxynaphthol blue TS
Preparation – Dissolve 0.1 g in ethyl alcohol and complete the volume to 100 mL with the same
solvent.
Change of color – On the pH range between 12.0 and 13.0, its solution has a red-pink color in
presence of calcium ions. With excess disodium edetate, it presents intense blue color.
Oracet blue B
CAS – [12769-16-3].
Molecular formula and molar mass – C21H16N2O2 – 328.37.
Specification – It is a mixture of 1-methylamino-4-anilino-anthraquinone with 1-amino-4-anilino-
anthraquinone.
Oracet blue B TS
Preparation – Dissolve 0.5 g of oracet blue B in glacial acetic acid and complete the volume to
100 mL using the same solvent.
Change of color – When used in titrations in non-aqueous medium, it changes from blue color (basic
medium) to purple (neutral medium) and to pink (acidic medium).
Thymol blue
CAS – [76-61-9].
Molecular formula and molar mass – C27H30O5S – 466.60.
Description – Brownish-green or greenish-blue crystalline powder.
Solubility – Slightly soluble in water, soluble in ethyl alcohol and in diluted alkali hydroxide
solutions.
Thymol blue TS
Preparation – Heat 0,1 g of thymol blue with 4.3 mL of 0.05% (w/v) sodium hydroxide and 5 mL of
90% (v/v) ethyl alcohol. After dissolution, complete the volume to 250 mL with 20% (v/v) ethyl
alcohol.
pH range – 1.2 – 2.8 and 8.0 – 9.6.
Change of color – Presents red color in strongly acidic solutions (pH range: 1.2 – 2.8), yellow color
in weakly acidic and alkaline solutions, and blue color in more alkaline solutions (pH range: 8.0 –
9.6).
Sensitivity test – The mixture of 0.1 mL of thymol blue TS, 100 mL of carbon dioxide-free water and
0.2 mL of 0.02 M sodium hydroxide presents a blue color. The color changes to yellow by adding no
more than 0.1 mL of hydrochloric acid 0.2 M.
Trypan blue
CAS – [72-57-1]
Formula and molecular mass – C34H24N6Na4O14S4 – 960.81
Nile blue A TS
Preparation – Dissolve 1 g in glacial acetic acid and complete the volume to 100 mL using the same
solvent.
pH range – 9.0 – 13.0.
Change of color – Provides blue color to strongly alkaline solutions and red color to weakly alkaline
solutions.
Sensitivity test – The mixture of 0.25 mL of Nile blue A TS in 50 mL of glacial acetic acid presents
blue color. The color turns greenish-blue by adding no more than 0.1 mL of perchloric acid 0.1 M to
glacial acetic acid.
Identification test – The solution at 0.0005% (w/v) in 50% (v/v) ethyl alcohol presents maximum
absorption (5.2.14) in 640 nm.
Calcon
CAS – [2538-85-4].
Molecular formula and molar mass – C20H13N2NaO5S – 416.38.
Description – Dark black powder with violet nuances.
Solubility – Very soluble in water and freely soluble in ethyl alcohol and acetone.
Calcon TS
Preparation – Dissolve 0.1 g of calcon in 100 mL of methyl alcohol.
Change of color – Provides purple-red color with calcium ions in alkaline medium. In presence of
excess disodium edetate, the solution acquires a blue color.
Methylrosanilinium chloride TS
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.1-01
Preparation – Dissolve 0.5 g of methylrosanilinium chloride in 100 mL of glacial acetic acid. Change
of color – In titrations in non-aqueous medium, the color changes from violet (less acidic medium) to
greenish-blue to yellow-blue (more acidic medium).
Sensitivity test – The mixture of 0.1 mL of methylrosanilinium chloride TS with 50 mL of glacial
acetic acid shows a blueish-purple color. The addition of 0.1 mL perchloric acid 0.1 M in acetic acid
changes the color to green.
Ferric chloride
CAS – [10025-77-1].
Synonym – Iron chloride.
Molecular formula and molar mass – FeCl3.6H2O – 270.30.
Description – Orange-yellow crystallized, deliquescent mass.
Solubility – Very soluble in water and soluble in ethyl alcohol and ethyl ether. Salt and its solutions,
exposed to light, suffer partial reduction.
BRP colorant
Preparation – Dissolve 0.1 g of bromothymol blue, 0.02 g of methyl red, and 0.2 g of
phenolphthalein in ethyl alcohol. Complete the volume to 100 mL with the same solvent. Filter.
Diphenylcarbazide
CAS – [140-22-7].
Molecular formula and molar mass – C13H14N4O – 242.28.
Description – White or nearly white crystalline powder, gradually turns pink with exposure to air.
Solubility – Very slightly soluble in water, soluble in acetone, in ethyl alcohol and in glacial acetic
acid.
Diphenylcarbazide TS
Preparation – Dissolve 1 g of diphenylcarbazide in 100 mL of hot ethyl alcohol. Store sheltered from
light.
Diphenylcarbazone
CAS – [538-62-5].
Molecular formula and molar mass – C13H12N4O – 240.27.
Description – Crystals or yellow-orange crystalline powder.
Solubility – Practically insoluble in water and freely soluble in ethyl alcohol.
Diphenylcarbazone TS
Preparation – Dissolve 0.1 g in 100 mL of ethyl alcohol. Store sheltered from light.
Eosin Y TS
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.1-01
Phenolphthalein
CAS – [77-09-8].
Molecular formula and molar mass – C20H14O4 – 318.33.
Description – Crystalline or amorphous powder, white or slightly yellow. Odorless.
Solubility – Insoluble in water and soluble in ethyl alcohol.
Phenolphthalein TS
Preparation – Dissolve 0.1 g in 100 mL of 80% (v/v) ethyl alcohol.
pH range – 8.3 – 10.0.
Change of color – Provides colorless solutions in acidic and weakly alkaline medium. Presents
intense violet color in stronger alkaline solutions.
Sensitivity test – The mixture of 0.1 mL of phenolphthalein TS with 1000 mL of carbon dioxide-free
water is colorless. No more than 0.2 mL of 0.02 M sodium hydroxide is necessary for the pink color
to appear.
Phenolphthalein, paper
Preparation – Immerse common filter paper strips in phenolphthalein TS for a few minutes and air-
dry at room temperature.
Ferroin
CAS – [14634-91-4].
Molecular formula and molar mass – C36H24FeN6O4S – 692.53
Ferroin TS
Preparation – Dissolve 0.7 g of ferrous sulfate heptahydrate and 1.49 g of 1,10-phenanthroline in
70 mL of water and complete the volume to 100 mL with the same solvent.
Sensitivity test – Add to 50 mL of M sulfuric acid 0.15 mL of osmium tetroxide RS and 0.1 mL of
ferroin TS. After adding 0.1 mL of ceric ammonium sulfate 0.1 M VS, the color changes from orange-
red to pale green.
Conservation – In tightly closed containers.
Magneson
CAS – [74-39-5].
Molecular formula and molar mass – C12H9N3O4 – 259.22
Description – Red-brown powder.
Magneson TS
Preparation – Dissolve 0,2 g of magneson in 100 mL of toluene.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.1-01
Change of color – In titrations in non-aqueous medium, it changes from orange (acidic medium) to
blue (basic medium), going through the pink color.
Magneson, reagent
Preparation – Dissolve 0.1 g of magneson in 100 mL of 1% (w/v) sodium hydroxide.
1-Naphtholbenzein
CAS – [6948-88-5].
Synonym – Phenylbis(4-hydroxynaphthyl)methanol.
Molecular formula and molar mass – C27H20O3 – 392.45.
Description – Red-brown powder.
Solubility – Insoluble in water, soluble in benzene, in ethyl ether and in glacial acetic acid.
1-Naphtholbenzein TS
Preparation – Dissolve 0.2 g of 1-naphtholbenzein in 100 mL of glacial acetic acid.
Change of color – When used in titrations in non-aqueous medium, it changes from blue or blueish-
green color (basic medium) to orange (neutral medium) and to dark green (acidic medium).
Sensitivity test – Add 0.25 mL of solution of 1-naphtholbenzein TS to 50 mL of glacial acetic acid.
No more than 0.05 mL of perchloric acid 0.1 M in glacial acetic acid is necessary to change the color
from brown-yellow to green.
1-Naphtholphthalein
CAS – [596-01-0].
Molecular formula and molar mass – C28H18O4 – 418.45.
Description – Colorless powder when pure, usually is greyish-red.
Solubility – Practically insoluble in water and soluble in ethyl alcohol.
1-Naphtholphthalein TS
Preparation – Dissolve 0.5 g in 100 mL of ethyl alcohol.
Change of color – Provides colorless or pale red solution in acidic and neutral media and blue color
in moderately alkaline solutions.
Eriochrome black T TS
Preparation – Dissolve 0.5 g of eriochrome black T and 4.5 g of hydroxylamine hydrochloride in
methyl alcohol and complete the volume to 100 mL using the same solvent. Prepare immediately
before use.
Change of color – In a medium comprised of hydrochloric acid it produces a brown-violet precipitate;
in medium comprised of sulfuric acid, it forms a dark blue precipitate that, when diluted, turns brown.
In aqueous sodium hydroxide solution, it presents a violet color.
Ammonium oxalate
CAS – [6009-70-7].
Molecular formula and molar mass – C2H8N2O4.H2O – 142.11.
Description – Colorless clear crystals or white crystalline powder. Odorless.
Solubility – Soluble in water.
Ammonium oxalate TS
Specification – Contains 4% (w/v) of ammonium oxalate in water.
Bromocresol purple
CAS – [115-40-2].
Molecular formula and molar mass – C21H16Br2O5S – 540.22.
Description – Pink crystalline powder.
Solubility – Practically insoluble in water, soluble in ethyl alcohol and diluted alkali hydroxide
solutions.
Bromocresol purple TS
Preparation – Heat 0.1 g of bromocresol purple with 5 mL of 90% (v/v) ethyl alcohol until
dissolution. Add 3.7 mL of 0.05 M sodium hydroxide and complete the volume to 250 mL with 20%
(v/v) ethyl alcohol.
pH range – 5.2 – 6.8.
Change of color – Provides yellow color in weakly acidic solutions and violet-blue color in alkaline,
neutral and acidic solutions that are very close to neutrality.
Sensitivity test – Mix 0.2 mL of bromocresol purple TS with 100 mL of carbon dioxide-free water.
Add 0.05 mL of 0.02 M sodium hydroxide. This solution has a violet-blue color. To change the color
to yellow, no more than 0.2 mL of hydrochloric acid 0.02 M is necessary.
M-cresol purple
CAS – [2303-01-7].
Molecular formula and molar mass – C21H16O5S – 380.41.
Description – Olive green crystalline powder.
Solubility – Slightly soluble in water, soluble in ethyl alcohol, glacial acetic acid and methyl alcohol.
M-cresol purple TS
Preparation – Dissolve 0.1 g of m-cresol purple in 100 mL of 0.001 M sodium hydroxide.
pH range – 0.5 – 2.5 and 7.5 – 9.2.
Change of color – Presents red color in strongly acidic solutions (pH range between 0.5 and 2,5);
yellow color in less acidic and neutral solutions; and violet color in moderately alkaline solutions (pH
range between 7.5 and 9.2).
Resazurin
CAS – [550-82-3].
Molecular formula and molar mass – C12H7NO4 – 229.19.
Description – Small dark red crystals with greenish luster.
Solubility – Insoluble in water and ethyl ether, slightly soluble in ethyl alcohol and soluble in diluted
alkali hydroxide solutions.
Resazurin TS
Preparation – Dissolve 0.1 g of resazurin in 100 mL of 0.02 M sodium hydroxide.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.1-01
Resorcinol
CAS – [108-46-3].
Synonym – Resorcine.
Molecular formula and molar mass – C6H6O2 – 110.11.
Description – Colorless or pale yellow crystalline powder or crystals; when exposed to light and air,
acquires a pink color.
Solubility – Soluble in water and ethyl alcohol.
Resorcinol TS
Preparation – Dissolve 0.2 g of resorcinol in 100 mL of benzene. Let it decant.
Thymolphthalein
CAS – [125-20-2].
Molecular formula and molar mass – C28H30O4 – 430.54.
Description – White or light yellow powder.
Solubility – Practically insoluble in water, soluble in ethyl alcohol and in alkali hydroxide solutions.
Thymolphthalein TS
Preparation – Dissolve 0.1 g of thymolphthalein in 100 mL of ethyl alcohol.
pH range – 9.3 – 10.5.
Change of color – It is colorless in acidic and weakly alkaline medium.
It provides a blue color in more intense alkaline solutions.
Sensitivity test – The mixture of 0.05 mL of thymolphthalein TS with 100 mL of carbon dioxide-free
water is colorless. No more than 0.05 mL of 0.1 M sodium hydroxide is necessary to change the color
to blue.
Ammonium thiocyanate
CAS – [1762-95-4].
Molecular formula and molar mass – NH4SCN – 76.12.
Description – Colorless and deliquescent crystals.
Solubility – Very soluble in water and soluble in ethyl alcohol.
Ammonium thiocyanate TS
Preparation – Dissolve 7.6 g of ammonium thiocyanate in 100 mL of water.
Litmus
CAS – [1393-92-6].
Specification – It is comprised of indigo blue pigment prepared from several species of
Rocella, Lecanosa or other lichens. The pigment has a characteristic odor.
Litmus TS
Preparation – Boil under reflux, for one hour, 25 g of litmus, finely powdered, with 100 mL of 90%
(v/v) ethyl alcohol. Discard the ethyl alcohol and repeat the operation twice, using in each extraction
75 mL of 90% (v/v) ethyl alcohol.
Add 250 mL of water to the litmus extracted. Filter.
pH range – 5.0 – 8.0.
Change of color – Provides red color in acidic medium and blue in alkaline medium.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.1-01
Tropaeolin O TS
Preparation – Dissolve 25 mg of tropaeolin in 50 mL of methyl alcohol and complete the volume to
100 mL with water.
pH range – 11.0 – 12.7.
Change of color – Provides yellow color solutions in moderately alkaline medium and orange color
in strongly alkaline solutions.
Homogeneity test – Apply 10 µL of tropaeolin O TS in a cellulose G TLC plate. Develop the
chromatogram with the mixture of n-propyl alcohol, ethyl acetate and water (5:1:4).
The chromatogram must show a single stain with Rf of, approximately, 0.9.
Bromocresol green
CAS – [76-60-8].
Molecular formula and molar mass – C21H14Br4O5S – 698.02.
Description – Brownish-white powder.
Solubility – Slightly soluble in water, soluble in ethyl alcohol and diluted alkali hydroxide solutions.
Bromocresol green TS
Preparation – Heat 0.1 g of bromocresol green with 2.9 mL of 0.05 M sodium hydroxide and 5 mL
of 90% (v/v) ethyl alcohol. After dissolution, complete the volume to 250 mL with 20% (v/v) ethyl
alcohol.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.1-01
Malachite green TS
Preparation – Dissolve 1 g of malachite green oxalate in 100 mL of glacial acetic acid.
pH range – 0.0-2.0.
Change of color – Provides yellow color in acidic solutions and green color in less acidic and alkaline
solutions.
Methyl green TS
Preparation – Dissolve 0.1 g of methyl green in 100 mL of water.
Change of color – In sulfuric acid solution, it presents a yellow color. By dilution, it returns to the
green color.
Cresol red
CAS – [1733-12-6].
Molecular formula and molar mass – C21H18O5S – 382.44.
Description – Red-brown crystalline powder.
Solubility – Slightly soluble in water, soluble in ethyl alcohol and diluted alkali hydroxide solutions.
Cresol red TS
Preparation – Heat 50 g of cresol red with 2.65 mL of 0.05 M sodium hydroxide and 5 mL of ethyl
alcohol 90%. After dissolution, complete the volume to 250 mL with 20% ethyl alcohol. pH range –
0.2 – 1.8 and 7.2 – 8.8.
Change of color – Provides red color in strongly acidic solutions (pH range between 0.2 and 1.8),
yellow color in less acidic and neutral solutions, and presents red color in moderately alkaline
solutions (pH range between 7.2 and 8.8).
Sensitivity test – The mixture of 0.1 mL of cresol red TS with 1000 mL of carbon dioxide-free water,
added with 0.15 mL of 0.02 M sodium hydroxide, presents a purple red color. The color changes to
yellow by adding no more than 0.15 mL of hydrochloric acid 0.02 M.
Congo Red TS
Preparation – Dissolve 0,25 mg of Congo red in 50 mL of 90% (v/v) ethyl alcohol and complete the
volume to 250 mL with water.
pH range – 3.0 – 5.0.
Change of color – Presents blue color in moderately acidic solutions and red color in weakly acidic
and alkaline solutions.
Sensitivity test – The mixture of 0.2 mL of Congo red TS, 100 mL of carbon dioxide-free water and
0.3 mL of hydrochloric acid 0.1 M has a blue color. No more than = 0.3 mL of 0.1 M sodium
hydroxide is necessary to change the color to pink.
Phenol red
CAS – [143-74-8].
Molecular formula and molar mass – C19H14O5S – 354.38.
Description – Light red or dark red crystalline powder.
Solubility – Very slightly soluble in water and slightly soluble in ethyl alcohol.
Phenol red TS
Preparation – Heat 0.1 g of phenol red with 1.42 mL of 0.2 M sodium hydroxide and 5 mL of 90%
(v/v) ethyl alcohol. After dissolution, complete the volume to 250 mL with 20% (v/v) ethyl alcohol.
pH range – 6.8-8.4.
Change of pH – Provides yellow color in neutral medium and red color in weakly alkaline solution.
Sensitivity test – The mixture of 0.1 mL of phenol red TS with 100 mL of carbon dioxide-free water
presents a yellow color. No more than 0.1 mL of 0.02 M sodium hydroxide is necessary to change the
color to red-violet.
Methyl red TS
Preparation – Heat 0.1 g of methyl red with 1.85 mL of 0.2 M sodium hydroxide and 5 mL of 90%
(v/v) ethyl alcohol. After dissolution, complete the volume to 250 mL with 50% (v/v) ethyl alcohol.
pH range – 3.0 – 4.4.
Change of color – Provides red color in weakly acidic solutions and yellow color in very weakly
acidic and alkaline solutions.
Sensitivity test – The mixture of 0.1 mL of methyl red TS, 100 mL of carbon dioxide-free water and
0.05 mL of hydrochloric acid 0.02 M presents a red color. No more than 0.1 mL of 0.02 M sodium
hydroxide is necessary to change the color to yellow.
Quinaldine red
CAS – [117-92-0].
Molecular formula and molar mass – C21H23IN2 – 430.33.
Description – Dark blue powder.
Solubility – Moderately soluble in water and freely soluble in ethyl alcohol.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.1-01
Quinaldine red TS
Preparation – Dissolve 0.1 g of quinaldine red in 100 mL of methyl alcohol.
Change of color – There is a change of color from crimson to nearly colorless.
Used in titrations of bases with perchloric acid.
Acetal
CAS – [105-57-7].
Molecular formula and molar mass – C6H14O2 – 118.18.
Description – Colorless, clear and volatile liquid.
Physical characteristics – Density (20 °C): approximately 0.824.
Refractive index (20 °C): approximately 1.382. Boiling temperature: approximately 103 °C.
Miscibility – Miscible with water and ethyl alcohol.
Acetaldehyde
CAS – [75-07-0].
Synonym – Ethanal.
Molecular formula and molar mass – C2H4O – 44.05.
Description – Colorless and clear liquid.
Physical characteristics – Density (20 °C): approximately 0.788.
Refractive index (20°C): approximately 1.332. Boiling temperature: approximately 21 °C.
Miscibility – Miscible with water and ethyl alcohol.
Safety – Flammable.
Acetanilide
CAS – [103-84-4].
Synonym – N-Phenylacetamide.
Molecular formula and molar mass – C8H9NO – 135.17.
Description – White crystalline, odorless powder.
Physical characteristic – Melting range: 114 °C to 116 °C.
Solubility – Slightly soluble in water, freely soluble in chloroform and ethyl alcohol, soluble in water
in ebullition, ethyl ether and glycerin.
Conservation – In closed containers.
Ammonium acetate
CAS – [631-61-8].
Molecular formula and molar mass – C2H7NO2 – 77.08.
Specification – Contains no less than 98.0% (w/w).
Description – Colorless crystals, very deliquescent, with faint acetic odor.
Solubility – Very soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Ammonium acetate RS
Specification – Contains 15% (w/v) of ammonium acetate in water.
Conservation – In tightly closed containers.
Stability – Prepare immediately before use.
Bornyl acetate
CAS – [5655-61-8].
Molecular formula and molar mass – C12H20O2 – 196.29.
Butyl acetate
CAS – [123-86-4].
Molecular formula and molar mass – C6H12O2 – 116.16.
Description – Colorless, flammable liquid, with sweet fruit odor.
Physical characteristics – Density (20 °C): approximately 0.88.
Refractive index (20 °C): approximately 1.395. Boiling range: 125 °C to 126 °C.
Solubility – Slightly soluble in water; miscible with ethyl alcohol and ethyl ether.
Conservation – In closed containers.
Cellulose acetate
CAS – [9004-35-7].
Specification – Partially acetylated cellulose, with varied degrees of acetylation.
Description – Amorphous white solid.
Category – Adsorbent in thin layer chromatography.
Chlorhexidine acetate
CAS – [56-95-1].
Molecular formula and molar mass – C26H38Cl2N10O4 – 625.56.
Description – White to pale beige crystals or powder; odorless.
Physical characteristic – Melting range: 154 °C to 155 °C.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Copper acetate
CAS – [142-71-2].
Molecular formula and molar mass – C4H6CuO4.H2O – 199.65.
Description – Bluish-green powder or crystals.
Solubility – Freely soluble in water in ebullition, soluble in water and ethyl alcohol, slightly soluble
in glycerol.
Cortisone acetate
CAS – [50-04-4].
Molecular formula and molar mass – C23H30O6 – 402.49.
Specification – Contains no less than 96.0% (w/w) in relation to the desiccated substance.
Description – Colorless faintly yellowed crystals or white or nearly white crystalline powder.
Odorless; initially insipid, then bitter.
Physical characteristics – Melting temperature: approximately 240 °C.
Specific optical rotation: +209 to +219 (determine in solution 1.0% [w/v] in dioxane).
Conservation – In tightly closed containers.
Storage – Protect from light.
Therapeutic class – Corticosteroid.
Desoxycortone acetate
CAS – [56-47-3].
Synonym – Desoxycorticosterone acetate.
Molecular formula and molar mass – C23H32O4 – 372.51.
Specification – Contains no less than 96.0% (w/w), calculated over the desiccated substance.
Description – Colorless crystals or white crystalline powder. Odorless.
Physical characteristics – Melting range: 157 °C to 161 °C.
Specific optical rotation: +171 to +179 (determine in solution 1.0% [w/v] in dioxane).
Conservation – In tightly closed containers.
Storage – Protect from light.
Therapeutic class – Corticosteroid.
Ethyl acetate
CAS – [141-78-6].
Molecular formula and molar mass – C4H8O2 – 88.11.
Specification – Contains no less than 99.9% (w/v).
Description – Clear, colorless, volatile liquid, with characteristic odor.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Phenylmercury acetate
CAS – [62-38-4].
Molecular formula and molar mass – C8H8HgO2 – 336.74.
Specification – Contains no less than 98.0% (w/w).
Description – Small crystals or white or bright beige crystalline powder.
Physical characteristic – Melting range: 149 °C to 153 °C.
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – Toxic. Pollutant.
Indophenol acetate RS
Synonym – 2,6-dichlorophenol-indophenol sodium in acetate buffer.
Preparation – Dilute 12 mL of the standard solution of 2,6-dichlorophenol-indophenol sodium in
100 mL of water. Add to this solution 100 mL of acetate buffer pH 7.0.
Conservation – In tightly closed containers. Stability – Use in within two weeks. Storage – Keep
under refrigeration.
Magnesium acetate
CAS – [16674-78-5].
Molecular formula and molar mass – C4H6MgO4.4H2O – 214.45.
Description – Colorless and deliquescent crystals.
Solubility – Freely soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Menthyl acetate
CAS – [2623-23-6].
Molecular formula and molar mass – C12H22O2 – 198.31.
Description – Colorless liquid.
Physical characteristics – Density (20 °C): approximately 0.92. Refractive index (20 °C):
approximately 1.447. Boiling temperature: approximately 228 °C.
Solubility – Slightly soluble in water; miscible with ethyl alcohol.
Mercury acetate
CAS – [1600-27-7].
Synonym – Mercuric acetate.
Molecular formula and molar mass – C4H6HgO4 – 318.68.
Description – Crystals or white or nearly white crystalline powder, with faint acetic odor. Physical
characteristic – Melting range: 178 °C to 180 °C (under heating results in decomposition).
Conservation – In tightly closed containers
Storage – Protect from light.
Safety – Toxic.
Mercury acetate RS
Preparation – Dissolve 6 g of mercury acetate in glacial acetic acid and complete the volume to
100 mL with the same solvent.
Conservation – In closed containers.
Storage – Protect from direct sunlight.
Methyl acetate
CAS – [79-20-9].
Molecular formula and molar mass – C3H6O2 – 74.08.
Description – Colorless and clear liquid.
Physical characteristics – Density (20 °C): approximately 0.933. Refractive index (20 °C):
approximately 1.361. Boiling range: 56 °C to 58 °C.
Solubility – Soluble in water; miscible with ethyl alcohol.
Potassium acetate
CAS – [127-08-2].
Molecular formula and molar mass – C2H3KO2 – 98.14.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Colorless crystals or white crystalline powder, odorless or with faint acetic odor.
Deliquescent.
Physical characteristic – Melting temperature: 292 °C.
Conservation – In tightly closed containers.
Potassium acetate RS
Specification – Contains 10 g of potassium acetate in 100 mL of water.
Conservation – In tightly closed containers.
Prednisolone acetate
CAS – [52-21-1].
Molecular formula and molar mass – C23H30O6 – 402.49.
Specification – Contains no less than 96.0% (w/w) calculated in relation to the desiccated substance.
Description – White or nearly white crystalline powder. Odorless. Bitter.
Physical characteristics – Melting temperature: approximately 247 °C.
Specific optical rotation: +112 to +119 (determine in solution 1.0% [w/v] in dioxane).
Conservation – In tightly closed containers.
Therapeutic class – Corticosteroid.
Sodium acetate
CAS – [6131-90-4].
Molecular formula and molar mass – C2H3NaO2.3H2O – 136.08 (if anhydrous – 82.03).
Specification – Contains no less than 99.0% (w/w).
Description – Colorless crystals or white crystalline powder, odorless or with faint acetic odor.
Efflorescent.
Conservation – In tightly closed containers.
Uranyl acetate
CAS – [6159-44-0].
Molecular formula and molar mass – C4H6O6U.2H2O – 424.15.
Description – Yellow crystalline powder, with faint acetic odor.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Zinc acetate
CAS – [5970-45-6].
Molecular formula and molar mass – C4H6O4Zn.2H2O – 219.50.
Specification – Contains no less than 98.0% (w/w).
Description – Colorless or white crystals, or crystalline scales or granules, with faint acetic odor and
astringent metallic flavor. Efflorescent.
Physical characteristic – Melting temperature: 237 °C.
Solubility – Freely soluble in water and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Irritant.
Acetylacetone
CAS – [123-54-6].
Molecular formula and molar mass – C5H8O2 – 100.12.
Description – Clear, colorless or yellow liquid, with aromatic odor.
Physical characteristics – Boiling temperature: approximately 139 °C.
Density: approximately 0.97. Refractive index (20 °C): 1.4505 to 1.4525.
Miscibility – Miscible with acetone and ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Irritant. Flammable.
Acetone
CAS – [67-64-1].
Molecular formula and molar mass – C3H6O – 58.08
Specification – Contains no less than 98.0% (w/v).
Description – Clear, colorless, volatile liquid, with characteristic odor.
Physical characteristics – Density: 0.790 to 0.793. Refractive index (20 °C): 1.358 to 1.360.
Boiling temperature: approximately 56 °C.
Conservation – In hermetic containers.
Safety – Flammable. Irritant and toxic.
Dehydrated acetone
Specification – Acetone, dehydrated in anhydrous sodium sulfate.
Conservation – Prepare immediately before use.
Buffered acetone RS
Preparation – Dissolve 8.15 g of sodium acetate trihydrate and 42 g of sodium chloride in water, add
68 mL of hydrochloric acid 0.1 M and 150 mL of acetone.
Complete the volume to 500 mL with water.
Acetonitrile
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
CAS – [75-05-8].
Molecular formula and molar mass – C2H3N – 41.05.
Description – Clear and colorless liquid. Odor similar to ether.
Physical characteristics – Density (20 °C): approximately 0.78. Refractive Index (20 °C):
approximately 1.344.
Miscibility – Miscible with water, acetone and methyl alcohol.
Conservation – In hermetic containers.
Safety – Toxic. Flammable.
Acetic acid M
Specification – Contains 6% (w/v) of glacial acetic acid in water.
Conservation – In hermetic containers.
Additional information – Confirm the titer before using.
6 M acetic acid
Specification – Contains 34.8% (w/v) of glacial acetic acid in water.
Conservation – In tightly closed containers.
Storage – Protect from heat.
Safety – Corrosive. Flammable.
Acetic acid RS
Specification – Contains 30% (w/v) of glacial acetic acid in water.
Corresponds to acetic acid 5 M.
Description – Clear, colorless liquid, with irritant odor.
Conservation – In hermetic containers.
7-aminodesacetoxycephalosporanic acid
CAS – [22252-43-3].
Synonym – 7-ADCA.
Molecular formula and molar mass – C8H10N2O3S – 214.24
Ascorbic acid
CAS – [50-81-7].
Molecular formula and molar mass – C6H8O6 – 176.12.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless crystals or white crystalline powder. Odorless.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Barbituric acid
CAS – [67-52-7].
Synonym – 1H,3H,5H-Pyrimidine-2,4,6-trione.
Molecular formula and molar mass – C4H4N2O3 – 128.09.
Description – White or nearly white powder.
Solubility – Moderately soluble in water, freely soluble in water in ebullition and in diluted acids.
Physical characteristic – Melting temperature: approximately 253 °C.
Benzoic acid
CAS – [65-85-0].
Molecular formula and molar mass – C7H6O2 – 122.12.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless crystals or white crystalline powder, with characteristic odor.
Physical characteristic – Melting temperature: approximately 122 °C.
Solubility – Moderately soluble in water, soluble in water in ebullition and freely soluble in ethyl
alcohol.
Conservation – In tightly closed containers.
Boric acid
CAS – [10043-35-3].
Molecular formula and molar mass – H3BO3 – 61.83.
Specification – Contains no less than 99.5% (w/w).
Description – Colorless bright crystals or white fine crystalline powder, unctuous to touch, with
weakly acid and bitter flavor.
Solubility – Soluble in water and in ethyl alcohol, freely soluble in water in ebullition.
Conservation – In tightly closed containers.
Hydrobromic acid
CAS – [10035-10-6].
Molecular formula and molar mass – HBr – 80.91.
Specification – Contains 48.0% (w/v).
Description – Colorless or faint yellow liquid, with strong and irritant odor.
Turns dark slowly by exposure to air and light.
Conservation – In tightly closed containers.
Storage – Protect from air and light.
Safety – Irritant. Corrosive.
Caffeic acid
CAS – [331-39-5].
Molecular formula and molar mass – C9H8O4 – 180.16.
Description – White or nearly white crystals.
Physical characteristic – Melting temperature: approximately 225 °C, with decomposition.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Solubility – Freely soluble in hot water and ethyl alcohol, moderately soluble in cold water.
Calconcarboxylic acid
CAS – [3737-95-9].
Molecular formula and molar mass – C21H14N2O7S – 438.41.
Description – Black-brown powder.
Solubility – Slightly soluble in water, very slightly soluble in acetone and in ethyl alcohol, moderately
soluble in diluted sodium hydroxide solutions.
Conservation – In tightly closed containers.
Cyclobutane-1,1-dicarboxylic acid
CAS – [5445-51-2].
Molecular formula and molar mass – C6H10O4 – 146.14.
Description – White crystals.
Physical characteristic – Melting temperature: approximately 160 °C.
Conservation – In closed containers.
1,2-cyclohexylene-dinitrilo-tetracetic acid
CAS – [125572-95-4].
Synonyms – 1,2-cyclohexylene-diamino-tetracetic acid, CDTA.
Molecular formula and molar mass – C14H22N2O8.H2O – 364.35. Description – White powder.
Conservation – Tightly closed containers, protected from heat.
Safety – Irritant.
Cinnamic acid
CAS – [140-10-3].
Molecular formula and molar mass – C9H8O – 132.16.
Description – Colorless crystals.
Physical characteristic – Melting temperature: 133 °C.
Solubility – Very slightly soluble in water and freely soluble in ethyl alcohol.
Hydrochloric acid
CAS – [7647-01-0].
Synonyms – Hydrogen chloride and concentrated hydrochloric acid.
Molecular formula and molar mass – HCl – 36.46.
Specification – Contains no less than 35.0% (w/w) comprised of gaseous HCl solution in water.
Description – Clear, colorless liquid, fuming, with irritant odor.
Physical characteristics – Density: approximately 1.18.
Conservation – In hermetic containers, of material inert to the reagent.
Storage – Protect from heat (maintain at temperatures below 20 °C).
Safety – Corrosive. Avoid external contact, eye and skin, inhalation and ingestion.
Hydrochloric acid M
Specification – Contains 10.3% (w/v) of hydrochloric acid in water.
Conservation – In tightly closed containers.
Stability – Protect from heat.
Safety – Corrosive.
Additional information – Confirm the titer before using.
Hydrochloric acid RS
Specification – Contains 27.4% (w/v) of concentrated hydrochloric acid in water.
Physical characteristics – Density: approximately 1.05.
Conservation – In tightly closed containers.
Stability – Protect from heat.
Safety – Corrosive.
Chlorogenic acid
CAS – [327-97-9].
Molecular formula and molar mass – C16H18O9 – 354.31.
Description – White or nearly white crystalline powder or needles.
Physical characteristic – Melting temperature: approximately 208 °C.
Solubility – Freely soluble in water in ebullition, in acetone and in ethyl alcohol.
Chloroplatinic acid
CAS – [18497-13-7].
Synonyms – Platinic chloride, platinum chloride, chloroplatinic (IV) acid.
Molecular formula and molar mass – H2PtCl6.6H2O – 517.90
Specification – Contains no less than 37.0% (w/w) platinum.
Description – Brownish-yellow crystalline mass, very deliquescent.
Physical characteristics – Density: 2.431. Melting temperature: 60 °C.
Solubility – Freely soluble in water and soluble in ethyl alcohol.
Conservation – In closed containers.
Storage – Protect from light.
Safety – Toxic.
Chromic acid
Use chromium trioxide (CrO3).
3,5-dinitrobenzoic acid
CAS – [99-34-3].
Molecular formula and molar mass – C7H4N2O6 – 212.12
Description – Practically colorless crystals.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Edetic acid
CAS – [60-00-4].
Synonyms – Ethylenediaminotetraacetic acid, EDTA.
Molecular formula and molar mass – C10H16N2O8 – 292.24
Specification – Contains no less than 98.0% (w/w).
Description – Colorless crystals.
Physical characteristic – Decomposes around 220 °C, can decarboxylate at 150 °C.
Conservation – In tightly closed containers.
Phenoldisulfonic acid RS
CAS – [96-77-5].
Molecular formula and molar mass – C6H6O7S2 – 254.24.
Description – Clear to light brown liquid.
Preparation – Dissolve 2.5 g of phenol in 15 mL of sulfuric acid.
Add 7.5 mL of fuming sulfuric acid. Heat at 100 °C for two hours.
Transfer the fluid product to an adequate container. To use, liquefy in water bath.
Conservation – Glass container with ground cap.
Safety – Irritant. Corrosive.
Phenoxyacetic acid
CAS – [122-59-8].
Molecular formula and molar mass – C8H8O3 – 152.15.
Description – Nearly white crystals.
Physical characteristic – Melting temperature: approximately 98 °C.
Solubility – Moderately soluble in water and freely soluble in ethyl alcohol and glacial acetic acid.
Hydrofluoric acid
CAS – [7664-39-3].
Molecular formula and molar mass – HF – 20.01.
Specification – Contains no less than 40% (w/w) of HF.
Description – Colorless and clear liquid.
Conservation – In tightly closed polyethylene containers.
Formic acid
CAS – [64-18-6].
Synonym – Methanoic acid.
Molecular formula and molar mass – CH2O2 – 46.03.
Specification – The anhydrous form contains no less than 98.0% (w/w).
Description – Colorless, very caustic liquid, with pungent odor.
Physical characteristics – Boiling temperature: 100.5 °C.
Density: approximately 1.22. Refractive index (20 °C): 1.3714 Solidifies at 70 °C.
Conservation – In tightly closed containers.
Safety – Caustic.
Phosphomolybdic acid
CAS – [51429-74-4].
Synonym – Molybdatophosphoric acid.
Molecular formula – Approximately 12MoO3.H3PO4.xH2O.
Description – Faint yellow crystals.
Conservation – In tightly closed containers.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Phosphomolybdic acid RS
Preparation – Dissolve 4 g of phosphomolybdic acid in 40 mL water while heating.
Add 60 mL of sulfuric acid after cooling.
Phosphoric acid
CAS – [7664-38-2].
Synonym – Orthophosphoric acid.
Molecular formula and molar mass – H3PO4 – 97.99.
Specification – Contains no less than 85.0% (w/w).
Description – Clear, colorless, odorless liquid. Hygroscopic. Syrupy consistence.
Physical characteristic – Density (20 °C): approximately 1.7.
Conservation – In hermetic containers.
Safety – Corrosive. Avoid contact with skin and mucous membranes.
Phosphoric acid RS
Preparation – Mix an amount corresponding to 15 g of concentrated phosphoric acid with water until
getting to 100 mL.
Physical characteristic – Density: approximately 1.15.
Phosphotungstic acid RS
Preparation – Heat under reflux for three hours the mixture of 10 g of sodium tungstate with 8 mL
of phosphoric acid and 75 mL of water. Let it cool down and dilute to 100 mL with water.
Phthalic acid
CAS – [88-99-3].
Molecular formula and molar mass – C8H6O4 – 166.13.
Description – White or nearly white crystalline powder.
Solubility – Soluble in hot water and in ethyl alcohol.
Gallic acid
CAS – [5995-86-8].
Molecular formula and molar mass – C7H6O5.H2O – 188.14.
Description – Long needles or colorless or light yellow crystalline powder.
Physical characteristics – Loses crystallization water at temperature of 120 °C and fuses at
approximately 206 °C, with decomposition.
Solubility – Soluble in water, freely soluble in hot water, in ethyl alcohol and in glycerol.
p-hydroxybenzoic acid
CAS – [99-96-7].
Molecular formula and molar mass – C7H6O3 – 138.12.
Description – Colorless crystals.
Physical characteristic – Melting range: 213 °C to 214 °C.
Conservation – In tightly closed containers.
Hypophosphorous acid
CAS – [6303-21-5].
Synonym – Diluted hypophosphorous acid.
Molecular formula and molar mass – H3PO2 – 66.00.
Specification – Contains no less than 48% (w/v) of H3PO2.
Description – Colorless or slightly yellow liquid.
Miscibility – Miscible with water and ethyl alcohol.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Hydriodic acid
CAS – [10034-85-2].
Molecular formula and molar mass – HI – 127.91.
Description – Aqueous solution of hydriodic acid. When freshly prepared, it is colorless, but with
exposure to air and light it presents a yellow to brown color.
Conservation – In tightly closed containers.
Storage – Protect from light and from contact with air. Maintain at a temperature below 30 °C.
Lactic acid
CAS – [50-21-5].
Synonym – 2-hydroxypropionic acid.
Molecular formula and molar mass – C3H6O3 – 90.08.
Specification – Mixture of 2-hydroxypropionic acid and its condensation products.
The equilibration between lactic acid and polylactic acid depends on concentration and temperature.
Lactic acid is usually a racemate ((RS)-lactic acid)c.
Description – Colorless or slightly yellow viscous liquid.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In closed containers.
Metaphosphoric acid
CAS – [10343-62-1].
Molecular formula and molar mass – (HPO3)n, monomer – 79.98.
Specification – Contains a certain ratio of sodium metaphosphate.
Description – Colorless solid or vitreous mass. Hygroscopic.
In aqueous solution, slowly turns into phosphoric acid (H3PO4).
Physical characteristic – Volatilizes under intense heating.
Conservation – In hermetic containers.
Methanesulfonic acid
CAS – [75-75-2].
Molecular formula and molar mass – CH4O3S – 96.11.
Description – Clear and colorless liquid (solidifies at 20 °C).
Physical characteristics – Density (20 °C): approximately 1.48.
Refractive index: approximately 1.430. Melting temperature: 20 °C.
Solubility – Miscible with water; slightly soluble in toluene and practically insoluble in hexane.
Conservation – In tightly closed containers.
Safety – Irritant.
Methoxyphenylacetic acid
CAS – [7021-09-2].
Molecular formula and molar mass – C9H10O3 – 166.18
Synonym – (RS)-2-Methoxy-2-phenylacetic acid.
Description – White and crystalline powder, or white or nearly white crystals.
Physical characteristic – Melting temperature: approximately 70 °C.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Nitric acid
CAS – [7697-37-2].
Molecular formula and molar mass – HNO3 – 63.01.
Specification – Contains no less than 63.0% (w/w).
Description – Clear, practically colorless solution, with characteristic odor.
Physical characteristic – Density (20 °C): 1.384 to 1.416.
Conservation – In hermetic containers, protected from light. Safety – Corrosive.
Nitric acid RS
Specification – Contains approximately 12.5% (w/v) of nitric acid.
Physical characteristic – Density: approximately 1.5.
4-nitrobenzoic acid
CAS – [62-23-7].
Molecular formula and molar mass – C7H5NO4 – 167.12.
Description – Yellow crystals.
Physical characteristic – Melting temperature: approximately 240 °C.
Oxalic acid
CAS – [6153-56-6].
Synonym – Ethanedioic acid.
Molecular formula and molar mass – C2H2O4.2H2O – 126.06.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless crystals or white crystalline powder.
Physical characteristic – Melting temperature: approximately 101 °C.
Safety – Poison!
Oxalic acid RS
Specification – 6.3% (w/v) solution of oxalic acid in water.
Perchloric acid
CAS – [7601-90-3].
Molecular formula and molar mass – HClO4 – 100.46.
Specification – Contains no less than 70.0% (w/w) and no more than 72.0% of perchloric acid.
Description – Clear, colorless, volatile liquid, with pungent odor. Hygroscopic.
Physical characteristic – Density: approximately 1.7.
Conservation – Decomposes spontaneously, may explode especially in contact with oxidizable
substances.
Safety – Irritant. Corrosive.
Perchloric acid M
Specification – Contains 8.5 mL of perchloric acid in water, completing the volume to 100 mL.
Stability – Prepare immediately before use.
Perchloric acid RS
Use perchloric acid M.
Performic acid
CAS – [107-32-4].
Synonym – Peroxyformic acid.
Molecular formula and molar mass – CH2O3 – 62.02.
Preparation – Mix 1 mL of hydrogen peroxide at 30.0% (v/v), or 9.0% (w/w), with 90 mL of formic
acid.
Conservation – Prepare immediately before use.
Storage – Protect from heat.
Safety – Irritant. It may explode in contact with metals, their oxides, reducing substances, or in
distillation.
Periodic acid
CAS – [10450-60-9].
Molecular formula and molar mass – H5IO6 – 227.93.
Description – White to colorless crystals.
Physical characteristics – Melting temperature: 122 °C.
Decomposes between 130 °C and 140 °C, forming I2O5, H2O and O2.
Solubility – Freely soluble in water and soluble in ethyl alcohol.
Picric acid
CAS – [88-89-1].
Synonym – 2,4,6-Trinitrophenol.
Molecular formula and molar mass – C6H3N3O7 – 229.10.
Specification – Yellow crystals or plates wetted with water.
Conservation – In tightly closed containers, mixed with an equal mass of water.
Storage – At room temperature.
Safety – Explodes when heated quickly or submitted to shock.
For safe transportation, 10% to 20% of water are usually added.
Picric acid RS
Preparation – Add 0.25 mL of sodium hydroxide 10 M to 100 mL of saturated picric acid solution in
water.
Rosmarinic acid
CAS – [20283-92-5].
Molecular formula and molar mass – C18H16O8 – 360.32.
Description – Orange-red powder.
Physical characteristic – Melting range: 170 °C to 174 °C.
Salicylic acid
CAS – [69-72-7].
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Selenious acid
CAS – [7783-00-8].
Molecular formula and molar mass – H2SeO3 – 128.97.
Specification – Contains no less than 93.0% (w/w) of selenious acid.
Description – White or colorless crystals. Efflorescent to dry air and hygroscopic to humid air.
Solubility – Soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Sulfamic acid
CAS – [5329-14-6].
Synonym – Amidosulfonic acid.
Molecular formula and molar mass – H3NO3S – 97.09.
Specification – White crystals or crystalline powder.
Physical characteristic – Melting temperature: approximately 205 °C, with decomposition.
Solubility – Freely soluble in water, moderately soluble in acetone, in ethyl alcohol and in methyl
alcohol.
Conservation – In tightly closed amber glass containers.
Safety – Moderately irritating to skin and mucous membranes.
Sulfanilic acid
CAS – [6101-32-2].
Synonym – 4-aminobenzenesulfonic acid.
Molecular formula and molar mass – C6H7NO3S.H2O – 191.20; anhydrous – 173.19.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless crystals or white powder.
Physical characteristic – The monohydrate acid decomposes without melting at approximately
288 °C.
Solubility – Moderately soluble in water, practically insoluble in ethyl alcohol.
Sulfanilic acid RS
Preparation – Dissolve 0.5 g of sulfanilic acid finely powdered in water. Add 6 mL of 6 M
hydrochloric acid. Complete the volume to 100 mL with water.
Sulfuric acid
CAS – [7664-93-9].
Molecular formula and molar mass – H2SO4 – 98.07.
Specification – Contains no less than 95.0% (w/w).
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Sulfuric acid RS
Specification – Contains 10% (w/v) of sulfuric acid in water.
Preparation – Carefully add 57 mL of sulfuric acid to 100 mL of water, cool down and complete the
volume to 1000 mL with water.
Conservation – In tightly closed containers.
Sulfurous acid
CAS – [7782-99-2].
Molecular formula and molar mass – H2SO3 – 82.07.
Specification – Contains 5.0 to 6.0% (w/w) of pure sulfur dioxide.
Prepare according to the consumption.
Description – Acid, clear, colorless liquid, with suffocating odor of sulfur dioxide.
On air, oxidizes gradually to sulfuric acid.
Conservation – In almost full containers, tightly closed, in a cool place.
Tartaric acid
CAS – [87-69-4].
Synonym – L-(+)-tartaric acid.
Molecular formula and molar mass – C4H6O6 – 150.09.
Description – White crystalline crystals or powders.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Physical characteristics – Melting range: 168 °C to 170 °C. Density (20 °C): 1.756.
Solubility – Very soluble in water and freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Thioglycolic acid
CAS – [68-11-1].
Synonym – Mercaptoacetic acid.
Molecular formula and molar mass – C2H4O2S – 92.11.
Specification – Contains no less than 79.0% (w/w).
Description – Colorless or nearly colorless liquid, with strong unpleasant odor.
Physical characteristic – Density: approximately 1.33.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – Protect from air.
Safety – May cause severe burns to the skin.
Additional information – Its decomposition releases hydrogen sulfide.
p-toluenesulfonic acid
CAS – [6192-52-5].
Molecular formula and molar mass – C7H8O3S.H2O – 190.21.
Specification – Contains no less than 87.0% of p-toluenesulfonic acid (C7H8O3S).
Description – White or nearly white crystalline powder or crystals.
Solubility – Freely soluble in water and soluble in ethyl alcohol.
Trichloroacetic acid
CAS – [76-03-9].
Molecular formula and molar mass – C2HCl3O2 – 163.39.
Specification – Contains no less than 98.0% (w/w).
Description – Colorless crystals or crystalline mass, deliquescent, with characteristic faintly pungent,
irritant odor.
Physical characteristic – Melting range: 55 °C to 61 °C.
Conservation – In hermetic containers.
Storage – Protect from heat and humidity.
Safety – Very corrosive acid.
Trichloroacetic-chloramine-T acid RS
Solution A – 3% (w/v) chloramine-T.
Solution B – 25% (v/v) trichloroacetic acid in absolute ethyl alcohol.
Preparation – Mix 10 mL of Solution A with 40 mL of Solution B.
Trifluoroacetic acid
CAS – [76-05-1].
Synonym – TFA.
Molecular formula and molar mass – C2HF3O2 – 114.02.
Description – Clear, volatile liquid, with characteristic irritant odor.
Physical characteristics – Boiling temperature: 72.4 °C. Density: 1.535.
Miscibility – Miscible with acetone, benzene, ethyl alcohol, ethyl ether, hexane and carbon
tetrachloride.
Conservation – In tightly closed containers.
Safety – Corrosive. Flammable. Protect eyes, skin and mucous membranes.
Acrylamide
CAS – [79-06-1].
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Synonym – 2-Propenamide.
Molecular formula and molar mass – C3H5NO – 71.08.
Specification – Appropriate quality for electrophoresis.
Description – White or nearly white crystalline powder, or colorless or white scales.
Physical characteristic – Melting temperature: approximately 84 °C.
Solubility – Very soluble in water and methyl alcohol, freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Highly toxic and irritant. Causes paralysis of the central nervous system. It may be absorbed
by intact skin.
Agar
CAS – [9002-18-0].
Synonyms – Agar-agar, gum agar.
Specification – Polysaccharide extracted from Gelidium cartilagineum (L) Gaillon (Gelidiaceae),
Gracilaria confervoides (L) Greville (Sphaerococcaceae) and similar red algae (Rhodophyceae).
Description – Fine, colorless or slightly yellowed dry, hydrophilic powder.
Conservation – In hermetic containers.
Agarose, gel
CAS – [9012-36-6].
Specification – Linear, neutral polysaccharide, component of agar.
Description – White or nearly white powder.
Solubility – Practically insoluble in cold water and very slightly soluble in hot water.
Use – Electrophoresis.
Bromine water RS
Preparation – Mix 3 mL of bromine with 100 mL of water until saturation. Shake before use. After
decanting, use the clear supernatant solution.
Conservation – In hermetic containers.
Storage – Preserve with excess bromine and protected from light.
Safety – Toxic.
Chlorine water RS
Specification – Saturated chlorine solution in water.
Conservation – In tightly closed containers.
Storage – Protect from light and from air. Keep in a cold, dark place.
Ammonia-free water
Preparation – Transfer 0.1 mL of 96% (w/w) sulfuric acid to 100 mL of water and distill using an
equipment with ammonia-free walls.
Nitrate-free water
Preparation – Transfer 5 mg of potassium permanganate and 5 mg of barium hydroxide to 100 mL
of water and distill using an equipment with nitrate-free walls.
Particle-free water
Specification – Water obtained by membrane filtration with 0.22 μm of pore size.
Bovine albumin
CAS – [9048-46-8].
Synonym – Bovine serum albumin.
Description – White or light yellowed-brown powder.
Specification – Contains no less than 96% of proteins.
Water (5.2.20.3) – Determine in 0.8 g of the sample. No more than 30%.
Storage – At temperatures between 2 °C and 8 °C.
Human albumin
Synonym – Human serum albumin.
Specification – Contains no less than 96% of albumin.
Butyl alcohol
CAS – [71-36-3].
Synonyms – 1-butanol, n-butanol, n-butyl alcohol.
Molecular formula and molar mass – C4H10O – 74.12.
Description – Clear, colorless, retractive liquid, with characteristic odor.
Physical characteristics – Boiling range: 117 °C to 118 °C. Density (20 °C): 0.810. Refractive index
(20 °C): 1.3993
Conservation – In tightly closed containers.
Safety – Irritant. Flammable.
Ethyl alcohol
CAS – [64-17-5].
Synonym – Ethanol.
Molecular formula and molar mass – C2H6O – 46.07.
Specification – Contains no less than 96.0% (v/v).
Description – Clear, colorless, volatile liquid, with characteristic odor.
Physical characteristics – Boiling temperature: approximately 78 °C. Density: 0.803 to 0.808.
Miscibility – Miscible with water and with methylene chloride.
Conservation – In tightly closed containers.
Storage – Protect from heat.
Safety – Toxic. Flammable.
Isoamyl alcohol
CAS – [123-51-3].
Synonym – 3-Methyl-1-butanol.
Molecular formula and molar mass – C5H12O – 88.15.
Description – Colorless liquid.
Physical characteristic – Boiling temperature: approximately 130 °C.
Solubility – Slightly soluble in water; miscible with ethyl alcohol.
Isobutyl alcohol
CAS – [78-83-1].
Synonyms – 2-Methylpropanol, 2-methyl-1-propanol, isobutanol.
Molecular formula and molar mass – C4H10O – 74.12.
Description – Colorless and clear liquid.
Physical characteristics – Density (20 °C): approximately 0.80. Refractive index (15 °C): 1.397 to
1.399. Boiling temperature: approximately 107 °C.
Conservation – In tightly closed containers.
Safety – Flammable.
Isopropyl alcohol
CAS – [67-63-0].
Synonyms – Isopropanol, 2-propanol.
Molecular formula and molar mass – C3H8O – 60.10.
Specification – Contains no less than 99.0%.
Description – Colorless liquid, with characteristic odor.
Physical characteristics – Boiling temperature: approximately 82 °C.
Density: approximately 0.785. Refractive index (20 °C): 1.376 to 1.378.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Flammable.
Methyl alcohol
CAS – [67-56-1].
Synonym – Methanol.
Molecular formula and molar mass – CH4O – 32.04.
Specification – Contains no less than 99.5% (w/v).
Description – Clear, colorless, flammable liquid, with characteristic odor.
Physical characteristics – Boiling temperature: 64 °C to 65 °C.
Density: 0.791 to 0.793. Refractive index (20 °C): 1.328 to 1.330.
Conservation – In hermetic containers.
Safety – Toxic. Flammable.
n-amyl alcohol
CAS – [71-41-0].
Synonyms – 1-Pentanol, pentyl alcohol.
Molecular formula and molar mass – C5H12O – 88.15.
Description – Colorless liquid.
Physical characteristics – Refractive index (20 °C): approximately 1.41.
Boiling temperature: approximately 137 °C. Melting temperature: approximately -79 °C.
Solubility – Moderately soluble in water; miscible with ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Irritant.
n-propyl alcohol
CAS – [71-23-8].
Synonyms – 1-Propanol, propanol.
Molecular formula and molar mass – C3H8O – 60.10.
Description – Clear, colorless liquid, with faint alcoholic odor.
Physical characteristics – Boiling temperature: approximately 97 °C
Density (20 °C): 0.802 to 0.806.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Flammable.
Polyvinyl alcohol
CAS – [9002-89-5].
Molecular formula – (C2H4O)n.
Description – White powder.
Solubility – Soluble in water and insoluble in organic solvents.
Tert-amyl alcohol
CAS – [75-85-4].
Synonym – 2-Methyl-2-butanol.
Molecular formula and molar mass – C5H12O – 88.15.
Description – Clear and colorless liquid. Volatile.
Physical characteristics – Density (20 °C): approximately 0.81.
Melting temperature: approximately -8 °C. Boiling temperature: 102 °C.
Miscibility – Easily miscible with water. Miscible with ethyl alcohol and in glycerol.
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – Flammable.
Tert-butyl alcohol
CAS – [75-65-0].
Synonym – 2-Methyl-2-propanol.
Molecular formula and molar mass – C4H10O – 74.12.
Description – Colorless and clear liquid, or crystalline mass with camphorated odor.
Physical characteristics – Density (25 °C): 0.778 to 0.782.
Melting temperature: 25.7 °C. Boiling temperature: 82.5 °C to 83.5 °C.
Solubility – Soluble in water; miscible with ethyl alcohol and with ethyl ether.
Aluminum, metallic
CAS – [7429-90-5].
Element and atomic mass – Al – 26.98.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Aluminon
CAS – [569-58-4].
Molecular formula and molar mass – C22H23N3O9 – 473.44.
Description – Red-brown crystals.
Solubility – Freely soluble in water.
Amaranth
Use amaranth red.
Iodized starch RS
Use iodized starch TS.
Iodide-free starch RS
Use iodide-free starch TS.
Soluble starch
Synonyms – Amylodextrin, amylogen. Description – Fine, odorless, insipid white powder.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Starch RS
Use starch TS.
Starches
Description – Extracted from mature caryopsis of Zea mays L., Triticum aestivum L. or Oryza sativa
L. (fam. Graminiae). Fine, odorless, insipid white powder that produces slight crepitation when compressed.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Additional information – The labeling must indicate the botanical origin.
4-Aminoantipyrine
CAS – [83-07-8].
Synonym – Aminopyrazolone.
Molecular formula and molar mass – C11H13N3O – 203.24
Description – Crystals or light yellow crystalline powder.
Physical characteristic – Melting temperature: approximately 109 °C.
Conservation – In tightly closed containers.
Aminobutanol
CAS – [96-20-8].
Synonym – 2-Amino-1-butanol.
Molecular formula and molar mass – C4H11NO – 89.14.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
2-Aminoheptane
CAS – [123-82-0].
Synonyms – 2-Heptanamine; 2-heptylamine; 1-methylhexanamine.
Molecular formula and molar mass – C7H17N – 115.22.
Description – Volatile liquid.
Physical characteristic – Boiling temperature: approximately 143 °C.
Miscibility – Slightly miscible with water, easily miscible with chloroform, ethyl alcohol and ethyl
ether.
4-Aminophenol
CAS – [123-30-8].
Molecular formula and molar mass – C6H7NO – 109.13.
Description – White crystalline powder or slightly colored due to exposure to air and light.
Physical characteristic – Melting temperature: approximately 186 °C, with decomposition.
Solubility –Moderately soluble in water and soluble in ethyl alcohol.
Conservation – In closed containers.
Storage – Protect from light.
2-Aminopyridine
CAS – [504-29-0].
Synonyms – α-Aminopyridine, 2-pyridinamine.
Description – Large crystals or leaflets.
Physical characteristic – Melting temperature: approximately 58 °C.
Ammonia RS
Description – Contains 37.5 mL of concentrated ammonia solution in 100 mL of aqueous solution.
Specification – Contains no less than 10% (w/v) of ammonium hydroxide (approximately 6 M).
Ammonia 6 M
Use ammonia RS
Ammonia 10 M
Preparation – Dilute 56 mL of ammonia to 100 mL with water.
Anethol
CAS – [4180-23-8].
Synonym – trans-Anethol.
Description – White or nearly white crystalline mass at temperature between 20 °C and 21 °C, liquid
at temperature above 23 °C.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Physical characteristics – Refractive index (25 °C): approximately 1.56. Boiling temperature:
approximately 230 °C.
Solubility – Practically insoluble in water, freely soluble in ethyl alcohol and soluble in ethyl acetate
and petroleum ether.
Acetic anhydride
CAS – [108-24-7].
Molecular formula and molar mass – C4H6O3 – 102.09.
Specification – Contains no less than 97.0% (w/w).
Description – Mobile, colorless liquid, intense and irritant acetic odor.
Physical characteristics – Density: approximately 1.075. Boiling range: 136 °C to 142 °C.
Conservation – In hermetic containers.
Safety – Easily combustible. Strong irritant.
Pyridine-acetic anhydride RS
Synonym – Pyridine-acetic anhydride mix RS.
Description – Carefully mix, under refrigeration, 25 g (or 23 mL) of acetic anhydride in 50 mL of
anhydrous pyridine.
Conservation – In hermetic containers.
Storage – Protect from air and light.
Stability – Prepare immediately before use. Safety – Toxic.
Phthalic anhydride
CAS – [85-44-9].
Molecular formula and molar mass – C8H4O3 – 148.12.
Description – White or nearly white flakes.
Physical characteristic – Melting range: 130 °C to 132 °C.
Solubility – Slightly soluble in water and soluble in ethyl alcohol.
Conservation – In closed containers.
Propionic anhydride
CAS – [123-62-6].
Molecular formula and molar mass – C6H10O3 – 130.14.
Description – Colorless liquid with pungent odor.
Physical characteristics – Density: 1.01. Boiling temperature: approximately 167 °C.
Solubility – Soluble in ethyl alcohol.
Aniline
CAS – [62-53-3].
Molecular formula and molar mass – C6H7N – 93.13.
Description – Colorless or slightly yellow liquid.
Physical characteristics – Density (20 °C): 1.02. Boiling temperature: 183 °C to 186 °C.
Conservation – Protected from light.
Anisaldehyde
CAS – [123-11-5].
Synonyms – Anisic aldehyde and p-methoxybenzaldehyde.
Molecular formula and molar mass – C8H8O2 – 136.15.
Description – Oily, colorless and yellow liquid, with aromatic odor.
Physical characteristics – Density: approximately 1.12.
Boiling temperature: approximately 248 °C.
Anisaldehyde, solution
Preparation – Mix, on the following order: Mix 0.5 mL of anisaldehyde, 10 mL of glacial acetic acid,
85 mL of methyl alcohol and 5 mL of sulfuric acid.
Anisaldehyde RS
Preparation – Add to 10 mL of anisaldehyde 90 mL of ethyl alcohol, mix, add 10 mL of sulfuric acid
and homogenize.
Anisaldehyde RS1
Preparation – Mix 25 mL of glacial acetic acid with 25 mL of ethyl alcohol, add 0.5 mL of
anisaldehyde and 1 mL of sulfuric acid.
Antithrombin III
CAS – [90170-80-2].
Specification – Antithrombin III is purified from human plasma by chromatography in gum agar-
heparin and must have specific activity of no less than 6 IU/mg.
Antithrombin III RS
Preparation – Reconstitute the antithrombin III according to specifications from the manufacturer
and dilute with sodium trichloride buffer of pH 7.5, to obtain a solution at 1 IU/mL.
Aprotinin
CAS – [9087-70-1].
Description – Nearly white powder.
Solubility – Soluble in water and in isotonic solutions, practically insoluble in organic solvents.
Asparagine
CAS –[5794-13-8].
Molecular formula and molar mass – C4H8N2O3.H2O – 150.13.
Description – Colorless, odorless crystals.
Physical characteristics – Isomer L: Melting temperature: 234-235 °C.
Isomer D: Melting temperature: 215 °C.
Solubility - Slightly soluble in water, practically insoluble in ethyl alcohol and in methylene chloride.
Sodium Azide
CAS – [26628-22-8].
Molecular formula and molar mass – NaN3 – 65.01.
Description – White or nearly white crystalline powder or crystals.
Solubility – Freely soluble in water and slightly soluble in ethyl alcohol.
Acid blue 83
CAS – [6104-59-2].
Synonym – Brilliant blue.
Molecular formula and molar mass – C45H44N3NaO7S2 – 825.97.
Description – Brown powder.
Solubility – Insoluble in cold water, slightly soluble in water in ebullition and in ethyl alcohol, soluble
in sulfuric acid and in glacial acetic acid, soluble in diluted alkali metal hydroxide solutions.
Acid blue 90
CAS – [6104-58-1].
Molecular formula and molar mass – C47H48N3NaO7S2 – 854.04.
Description – Dark brown powder, with violet reflexes and particles with metallic reflexes.
Solubility – Soluble in water and in ethyl alcohol.
Astra blue
CAS – [82864-57-1].
Molecular formula and molar mass – C47H52CuN14O6S3 – 1068.75.
Coomassie Blue RS
Preparation – Prepare a 0.125% (w/v) acetic blue 83 solution in a mixture of glacial acetic acid,
methyl alcohol and water (1:4:5) and filter.
Tetrazolium blue
CAS – [1871-22-3].
Molecular formula and molar mass – C40H32N8O2Cl2 – 727.65.
Description – Yellow crystals.
Physical characteristic – Melting temperature: approximately 245 °C, with decomposition.
Solubility – Slightly soluble in water, freely soluble in chloroform, ethyl alcohol and methyl alcohol,
insoluble in acetone and ethyl ether.
Canada Balsam
CAS – [8007-47-4].
Description – Yellow or greenish oily liquid, extracted from Abies balsames L., Pinaceae.
With pleasant odor of pine. If exposed to air, solidifies gradually into a non-crystalline mass.
Physical characteristics – Density: 0.987 to 0.994. Refractive index: 1.53.
Miscibility – Miscible with water, benzene, chloroform and xylene.
Additional information – Used to mount slides for microscope.
Barbaloin
CAS – [1415-73-2].
Synonym – Aloin.
Description – Yellow needles or yellow to dark yellow crystalline powder.
Turns dark with exposure to air and light.
Solubility – Moderately soluble in water and in ethyl alcohol, soluble in acetone, in ammonia and in
alkali hydroxide solutions.
Barbital
CAS – [57-44-3].
Molecular formula and molar mass – C8H12N2O3 – 184.20.
Specification – Contains no less than 99.0% (w/w) calculated in relation to the desiccated substance.
Description – Colorless crystals or white crystalline powder, odorless, with faintly bitter flavor.
Physical characteristic – Melting temperature: approximately 190 °C.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Solubility – Slightly soluble in water, soluble in water in ebullition and in ethyl alcohol.
Sodium barbital
CAS – [144-02-5].
Molecular formula and molar mass – C8H11N2NaO3 – 206.18
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Colorless crystals or white crystallized powder, odorless, with bitter flavor and weakly
caustic.
Solubility – Freely soluble in water and slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Benzene
CAS – [71-43-2].
Synonym – Benzol.
Molecular formula and molar mass – C6H6 – 78.11.
Description – Clear, colorless, refractive, volatile liquid, with characteristic odor.
Physical characteristics – Boiling range: 79 °C to 81 °C. Density: 0.878 to 0.880.
Refractive index: 1.5016.
Solubility – Practically insoluble in water; miscible with ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from heat.
Safety – Highly flammable. Carcinogenic.
Additional information – Use toluene whenever possible.
Benzenesulfonamide
CAS – [98-10-2].
Molecular formula and molar mass – C6H5SO2NH2 – 157.19.
Description – White or pale beige crystals.
Physical characteristic – Melting range: 150 °C to 153 °C.
Benzil
CAS – [134-81-6].
Synonym – Diphenylethanedione.
Molecular formula and molar mass – C14H10O2 – 210.23.
Description – Yellow crystalline powder.
Physical characteristic – Melting temperature: approximately 95 °C.
Solubility – Practically insoluble in water and soluble in ethyl alcohol, ethyl acetate and toluene.
Benzyl benzoate
CAS – [120-51-4].
Description – Oily, clear and colorless liquid. By cooling, forms colorless crystals. Physical
characteristics – Freezing temperature: approximately 17 °C.
Boiling temperature: approximately 324 °C.
Solubility – Practically insoluble in water and glycerol; miscible with ethyl alcohol, ethyl ether and
chloroform.
Cholesteryl benzoate
CAS – [604-32-0].
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Methyl benzoate
CAS – [93-58-3].
Molecular formula and molar mass – C8H8O2 – 136.15.
Description – Colorless liquid.
Physical characteristics – Density (20 °C): 1.088.
Boiling temperature: approximately 200 °C.
Benzophenone
CAS – [119-61-9].
Molecular formula and molar mass – C13H10O – 182.22.
Description – White crystalline powder.
Characteristics – Melting temperature: approximately 48 °C.
Solubility – Practically insoluble in water, freely soluble in ethyl alcohol.
Benzoin
CAS – [119-53-9].
Synonym – 2-Hydroxy-1,2-diphenylethanone.
Molecular formula and molar mass – C14H12O2 – 212.25.
Description – Slightly yellow crystals.
Solubility – Very slightly soluble in water, freely soluble in acetone, soluble in heated ethyl alcohol.
Sodium bicarbonate
CAS – [144-55-8].
Synonym – Sodium acid carbonate, sodium hydrogen-carbonate.
Molecular formula and molar mass – NaHCO3 – 84.01.
Specification – Contains no less than 99.0% (w/w) and no more than 101.0% (w/w) in relation to the
desiccated substance.
Description – White crystalline, odorless powder, of salty flavor and weakly alkaline. By heating,
turns into sodium carbonate.
Solubility – Soluble in water, practically insoluble in ethyl alcohol.
Disodium bicinchoninate
CAS – [979-88-4].
Molecular formula and molar mass – C20H10N2Na2O4 – 388.29.
Potassium biphthalate
CAS – [877-24-7].
Synonyms – Acid potassium phthalate, potassium hydrogen phthalate, potassium diphthalate.
Molecular formula and molar mass – C8H5KO4 – 204.22.
Specification – Contains no less than 99.9% (w/w) and no more than 100.3% (w/w) in relation to the
substance desiccated at 120 °C for two hours.
Description – Colorless crystals or white crystalline powder.
Solubility – Soluble in water and moderately soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Potassium bisulfate
CAS –[7646-93-7].
Synonyms – Potassium hydrogen sulfate; acid potassium sulfate.
Molecular formula and molar mass – KHSO4 – 136.16.
Specification – Contains no less than 98.0% (w/w) in relation to the desiccated substance.
Description – Colorless crystals or white mass. Hygroscopic.
Physical characteristics – Aqueous solution with strongly acidic character. Melting temperature: 197
°C.
Solubility – Freely soluble in water, resulting in a very acidic solution.
Conservation – In tightly closed containers.
Sodium bisulfate
CAS – [7681-38-1].
Synonyms – Acid sodium sulfate, sodium hydrogen sulfate, sodium pyrosulfate.
Molecular formula and molar mass – NaHSO4 – 120.06.
Physical characteristic – Melting temperature: approximately 315 °C.
Solubility – Freely soluble in water, very soluble in water in ebullition. Decomposes in ethyl alcohol,
forming sodium sulfate and free sulfuric acid.
Sodium bisulfite
CAS – [7631-90-5].
Synonyms – Sodium hydrogen sulfite, acid sodium sulfite.
Molecular formula and molar mass – NaHSO3 – 104.06.
Description – White or nearly white crystalline powder. The exposure to air may cause loss of sulfur
dioxide and the substance is gradually oxidized to sulfate.
Solubility – Freely soluble in water and moderately soluble in ethyl alcohol.
Sodium bitartrate
CAS – [6131-98-2].
Synonym – Acid sodium tartrate.
Molecular formula and molar mass – C4H5NaO6.H2O – 190.08.
Description – White crystals or crystalline powder.
Solubility – Soluble in water.
Sodium bitartrate RS
Preparation – Dissolve 1 g of sodium bitartrate in water and complete the volume to 10 mL.
Prepare immediately before use.
Biuret
CAS – [108-19-0].
Molecular formula and molar mass – C2H5N3O2 – 103.08.
Description – White or nearly white crystals. Hygroscopic.
Physical characteristic – Melting range: 188 °C to 190 °C, with decomposition.
Solubility – Soluble in water, moderately soluble in ethyl alcohol, very slightly soluble in ethyl ether.
Conservation – In closed container.
Biuret, reagent
Preparation – Dissolve 1.5 g of pentahydrate copper sulfate and 6 g of sodium tartrate and potassium
in 500 mL of water. Add 300 mL of carbonate-free sodium hydroxide solution to 10% (w/v),
complete the volume to 1000 mL with the same solution and mix.
Boldine
CAS – [476-70-0].
Molecular formula and molar mass – C19H21NO4 – 327.38.
Description – White or nearly white crystalline powder.
Physical characteristic – Melting temperature: approximately 163 °C.
Solubility – Very slightly soluble in water, soluble in ethyl alcohol and in diluted acid solutions.
Conservation – In closed containers.
Borneol
CAS – [507-70-0].
Molecular formula and molar mass – C10H18O – 154.25. Description – Colorless crystals, sublimate
quickly. Physical characteristic – Melting temperature: approximately 208 °C.
Solubility – Practically insoluble in water, freely soluble in ethyl alcohol and in petroleum ether.
Potassium bromate
CAS – [7758-01-2].
Molecular formula and molar mass – KBrO3 – 167.00.
Description – White or nearly white crystals or granular powder.
Solubility – Soluble in water and slightly soluble in ethyl alcohol.
Bromelain
CAS – [37189-34-7].
Specification – Concentrate of proteolytic enzymes derived from Ananas comosus Merr.
Description – Yellow powder.
Bromelain RS
Preparation – Dissolve 1 g of bromelain in 100 mL of a mixture comprised of phosphate buffer pH
5.5 and 0.9% (w/v) sodium chloride solution (1:9).
Dimidium bromide
CAS – [518-67-2].
Molecular formula and molar mass – C20H18BrN3 – 380.29.
Description – Dark red crystal.
Solubility – Slightly soluble in water at 20 °C, moderately soluble in water at 60 °C and in ethyl
alcohol.
Hexadimethrin bromide
CAS – [28728-55-4].
Molecular formula – (C13H30Br2N2)n.
Description – White or nearly white powder. Hygroscopic. Amorphous polymer.
Solubility – Soluble in water.
Conservation – In closed containers.
Iodine bromide
CAS – [7789-33-5].
Molecular formula and molar mass – IBr – 206.80.
Description – Dark brown or dark blue crystals.
Physical characteristics – Boiling temperature: approximately 116 °C.
Melting temperature: approximately 40 °C.
Solubility – Freely soluble in water, in ethyl alcohol and in glacial acetic acid.
Conservation – In closed containers.
Storage – Protect from light.
Iodine bromide RS
Preparation – Dissolve 13.2 g of iodine in glacial acetic acid and complete the volume to 1000 mL
with the same solvent. Determine the content of iodine in 20 mL of this solution, by titrating with
sodium thiosulfate 0.1 M VS. Add to the remaining iodine solution (980 mL) an amount of bromine
equivalent to the iodine determined.
Conservation – In tightly closed glass containers.
Storage – Protect from light.
Potassium bromide
CAS – [7758-02-3].
Molecular formula and molar mass – KBr – 119.00.
Specification – Contains no less than 98.0% (w/w) in relation to the desiccated substance.
Description – Colorless crystals or white crystalline powder, with markedly salty flavor.
Solubility – Freely soluble in water and in glycerol, slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Tetrabutylammonium bromide
CAS – [1643-19-2].
Molecular formula and molar mass – C16H36BrN – 322.38.
Description – White crystalline powder.
Physical characteristic – Melting range: between 103 °C and 105 °C.
Tetraheptylammonium bromide
CAS – [4368-51-8].
Molecular formula and molar mass – C28H60BrN – 490.70.
Description – White, scaly powder.
Physical characteristic – Melting range: between 89 °C and 91 °C.
Mercuric bromide
CAS – [7789-47-1].
Synonym – Mercury(II) bromide.
Molecular formula and molar mass – Br2Hg – 360.40.
Specification – White crystals or crystalline powder, sensitive to light.
Physical characteristics – Melting temperature: approximately 237 °C.
Solubility – Slightly soluble in water and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – Poison!
Bromine
CAS – [7726-95-6].
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Bromine RS
Preparation – Dissolve 30 g of bromine and 30 g of potassium bromide in water and complete the
volume to 100 mL with the same solvent.
Sodium butanesulfonate
CAS – [2386-54-1].
Molecular formula and molar mass – C4H9NaO3S – 160.16.
Description – White or nearly white crystalline powder.
Physical characteristic – Melting temperature: higher than 300 °C.
Solubility – Soluble in water.
Butyl hydroxyanisole
CAS – [25013-16-5].
Synonym – BHA.
Molecular formula and molar mass – C11H16O2 – 180.245.
Specification – Mixture of two isomers: 2-tert-butyl-4- hydroxyanisole and 3-tert-butyl-4-
hydroxyanisole
Description – Solid, of waxy aspect.
Physical characteristic – Melting range: from 48 °C to 55 °C.
Solubility – Practically insoluble in water and soluble in petroleum ether.
Conservation – In closed containers.
Butylamine
CAS – [109-73-9].
Synonym – n-Butylamine.
Molecular formula and molar mass – C4H11N – 73.14.
Description – Colorless liquid, with ammoniacal odor.
Physical characteristic – Boiling temperature: approximately 78 °C.
Miscibility – Miscible with water and ethyl alcohol.
Additional information – Distill and use within 30 days.
Butylparaben
CAS – [94-26-8].
Molecular formula and molar mass – C11H14O3 – 194.23.
Description – White crystalline powder.
Physical characteristic – Melting range: from 68 °C to 69 °C.
Solubility – Very slightly soluble in water and freely soluble in acetone, ethyl ether and chloroform.
Conservation – In closed containers.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Calciferol
CAS – [50-14-6].
Synonym – Ergocalciferol, vitamin D2.
Molecular formula and molar mass – C28H44O – 396.66.
Specification – 1 g corresponds, in anti-rickets activity, to 40,000,000 IU.
Description – Colorless crystals or white crystalline powder.
Solubility – Practically insoluble in water, freely soluble in ethyl alcohol, soluble in greasy oils.
Conservation – In hermetic containers, under inert gas.
Storage – Protect from heat and light.
Camphene
CAS – [79-92-5].
Molecular formula and molar mass – C10H16 – 136.24.
Camphor
CAS – [76-22-2].
Molecular formula and molar mass – C10H16O – 152.24.
Light kaolin
CAS – [1332-58-7].
Specification – Natural, hydrated, purified aluminum silicate. It contains an appropriate dispersing
agent.
Description – White power, little dense, free from gritty particles, unctuous to tact.
Solubility – Practically insoluble in water and in inorganic acids.
Coarse particles – Add 5 g of the sample to a cylinder with stopper (with 160 mm of length and
35 mm of internal diameter) and add 60 mL of 1% (w/v) sodium pyrophosphate solution. Shake
vigorously and allow to stand for five minutes. Using a pipette, take 50 mL of the supernatant liquid,
from a position approximately 5 cm below the preparation surface. Add to the remaining liquid 50
mL of water, shake, allow to stand for five minutes and take 50 mL of the liquid the same way as
previously described. Repeat the process until taking a total of 400 mL. Transfer the suspension to a
porcelain capsule, evaporate until dry in water bath, and desiccate at temperature between 100 °C and
105 °C until constant weight. The residue mass is not superior to 25 mg (0.5%).
Fine particles – Disperse 5 g of the sample in 250 mL of water, shake vigorously for 2 minutes, and
transfer immediately to a glass cylinder (with 50 mm of internal diameter). Using a pipette, transfer
20 mL of liquid to a watch glass. Evaporate until dry in water bath, and desiccate at temperature
between 100 °C and 105 °C until constant weight (m1). Allow the remaining suspension to stand at
20 °C for four hours. Take 20 mL of the liquid, from a position approximately 5 cm below the
preparation surface, avoiding to disperse the sediment. Transfer to a watch glass, evaporate until dry
in water bath, and desiccate at temperature between 100 °C and 105 °C until constant weight (m2).
The value of m2 is not inferior to 70% of the value of m1.
Ammonium carbonate
CAS – [506-87-6].
Molecular formula and molar mass – (NH4)2CO3 – 96.09.
Specification – Mixture in variable proportions of ammonium bicarbonate (NH4HCO3 – 79.06) and
ammonium carbamate (H2NCOONH4 – 78.07).
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Ammonium carbonate RS
Specification – Contains 15.8 g of ammonium carbonate in 100 mL of aqueous solution.
Conservation – In tightly closed containers.
Storage – Protect from light and from heat.
Calcium carbonate
CAS – [471-34-1].
Molecular formula and molar mass – CaCO3 – 100.09.
Specification – Contains no less than 98.5% (w/w) in relation to the desiccated substance.
Description – Odorless, insipid white powder.
Solubility – Practically insoluble in water.
Conservation – In tightly closed containers.
Strontium carbonate
CAS – [1633-05-2].
Molecular formula and molar mass – SrCO3 – 147.63.
Description – Odorless, insipid white powder.
Conservation – In tightly closed containers.
Lithium carbonate
CAS – [554-13-2].
Molecular formula and molar mass – Li2CO3 – 73.89.
Specification – Contains no less than 98.5% in relation to the desiccated substance.
Description – White, light, odorless powder.
Solubility – Sparingly soluble in water and very slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Potassium carbonate
CAS – [584-08-7].
Molecular formula and molar mass – K2CO3 – 138.20.
Description – Granular powder or white or nearly white granules. Hygroscopic.
Physical characteristic – Melting temperature: 891 °C.
Solubility – Moderately soluble in water and practically insoluble in ethyl alcohol.
Conservation – In tightly closed containers.
Sodium carbonate
CAS – [497-19-8].
Formula and molecular mass – Na2CO3 – 105.99.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – White, hygroscopic powder.
Solubility – Freely soluble in water.
Conservation – In hermetic containers.
Storage – Protect from humidity.
Sodium carbonate RS
Specification – Contains 10.6 g of sodium carbonate in 100 mL of aqueous solution.
Conservation – In tightly closed containers.
Carvone
CAS – [2244-16-8].
Molecular formula and molar mass – C10H14O – 150.22.
Description – Colorless liquid.
Physical characteristics – Density (20 °C): approximately 0.965. Refractive index (20 °C):
approximately 1.500. Boiling temperature: approximately 230 °C. Rotation power (20 °C):
approximately +61°.
Solubility – Practically insoluble in water; miscible with ethyl alcohol.
Catechin
CAS – [154-23-4].
Molecular formula and molar mass – C15H14O6.xH2O – 290.27 (for the anhydrous substance)
Physical characteristics – Melting range: 93 °C to 96 °C, or 175 °C to 177 °C when in anhydrous
form.
Cephalin
Specification – Consists of esters of glycerophosphoric acid with long-chain fatty acids, with the
phosphate group being esterified with ethanolamine.
Description – Amorphous yellow substance, of characteristic odor and flavor.
Category – Local hemostatic and laboratory reagent in hepatic function tests.
Cephalin RS
Chromatographic cellulose
CAS – [9004-34-6].
Synonym – Cellulose for chromatography.
Description – Fine, homogeneous white powder. The average particle size is no less than 30 μm.
Category – Support to chromatography.
Potassium cyanide
CAS – [151-50-8].
Molecular formula and molar mass – KCN – 65.12.
Specification – Contains no less than 96.0% (w/w) in relation to the desiccated substance.
Description – Crystalline powder, masses or white granules; deliquescent.
Physical characteristic – Melting temperature: 634 °C.
Conservation – In hermetic containers.
Storage – Protect from light.
Stability – Decomposes gradually by exposure to air, carbon dioxide and humidity.
Safety – Poison!
Potassium cyanide RS
Preparation – Dissolve 50 g of potassium cyanide in distilled water and complete the volume to
100 mL. Remove lead from this solution by extraction with successive portions of the dithizone
extractor solution. Extract the remaining dithizone in the cyanide solution stirring with chloroform.
Dilute the cyanide solution with enough distilled water so that every 100 mL has 10 g of potassium
cyanide
Conservation – In hermetic containers.
Safety – Poison!
Ammonia cyanide RS
Preparation – Dissolve 2 g of potassium cyanide in 15 mL of ammonium hydroxide and dilute to
100 mL with distilled water.
Ethyl cyanoacetate
CAS – [105-56-6].
Molecular formula and molar mass – C5H7NO2 – 113.12.
Description – Colorless or pale yellow liquid.
Physical characteristics – Density (25 °C): 1.056.
Boiling range: 205 °C to 209 °C, with decomposition.
Solubility – Slightly soluble in water; miscible with ethyl alcohol and ethyl ether.
Conservation – In tightly closed containers.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Cyclohexane
CAS – [110-82-7].
Molecular formula and molar mass – C6H12 – 84.16.
Description – Clear, colorless, volatile liquid, with characteristic odor (similar to gasoline). Physical
characteristics – Boiling temperature: approximately 80 °C
Density: approximately 0.78. Refractive index (20 °C): 1.426 to 1.427.
Solubility – Practically insoluble in water; miscible with organic solvents.
Conservation – In tightly closed containers.
Safety – Flammable.
Benzyl cinnamate
CAS – [103-41-3].
Molecular formula and molar mass – C16H14O2 – 238.29.
Description – Colorless or yellowed crystals.
Physical characteristic – Melting temperature: approximately 39 °C.
Methyl cinnamate
CAS – [103-26-4].
Molecular formula and molar mass – C10H10O2 – 162.19.
Description – Colorless crystals.
Physical characteristics – Melting range: 34 °C to 36 °C.
Boiling temperature: approximately 260 °C. Refractive index (20 °C): approximately 1.56.
Solubility – Practically insoluble in water and soluble in ethyl alcohol.
Cinchonine
CAS – [118-10-5].
Molecular formula and molar mass – C19H22N2O – 294.40.
Description – White or nearly white crystalline powder.
Physical characteristics – Specific rotation power (20 °C): +225° to +230°, determined on a 5% (w/v)
solution in ethyl alcohol. Melting temperature: approximately 263 °C.
Conservation – In closed containers.
Storage – Protect from exposure to light.
1,8-Cineole
CAS – [470-82-6].
Synonym – Eucalyptol.
Molecular formula and molar mass – C10H18O – 154.25.
Description – Colorless liquid.
Physical characteristics – Density (20 °C): 0.922 to 0.927. Refractive index (20 °C): 1.456 to 1.459.
Solubility – Practically insoluble in water; miscible with ethyl alcohol.
Citral
CAS – [5392-40-5].
Molecular formula and molar mass – C10H16O – 152.24.
Description – Light yellow liquid.
Solubility – Practically insoluble in water; miscible with ethyl alcohol and glycerol.
Ammonium citrate RS
Preparation – Dissolve 40 g of citric acid in 90 mL of distilled water. Add two or three drops of 0.1%
(w/v) phenol red in ethyl alcohol. Carefully add ammonium hydroxide until the solution acquires a
red color. Remove any lead present by extraction with portions of 20 mL of dithizone extractor
solution until the orange-green color in the dithizone solution is maintained.
Cupric citrate RS
Preparation – Dissolve 25 g of cupric sulfate pentahydrate, 50 g of citric acid monohydrate, and
144 g of sodium carbonate in water and dilute to 1000 mL with the same solvent.
Sodium citrate
CAS – [6132-04-3].
Synonym – Trisodium citrate.
Molecular formula and molar mass – C6H5Na3O7.2H2O – 294.10.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Crystals or crystalline white powder, odorless, with salty flavor, refreshing.
Deliquescent.
Solubility – Freely soluble in water and practically insoluble in ethyl alcohol.
Conservation – In tightly closed containers.
Citronellal
CAS – [106-23-0].
Molecular formula and molar mass – C10H18O – 154.25.
Description – Colorless or light yellow liquid.
Physical characteristics – Density (20 °C): 0.848 to 0.856. Refractive index (20 °C): approximately
1.446.
Solubility – Very slightly soluble in water and soluble in ethyl alcohol.
Citronellol
CAS – [106-22-9].
Molecular formula and molar mass – C10H20O – 156.27.
Description – Colorless and clear liquid.
Physical characteristics – Density (20 °C): 0.857.
Refractive index (20 °C): 1.456. Boiling range: 220 °C to 222 °C.
Solubility – Practically insoluble in water; miscible with ethyl alcohol.
Chloramine T
CAS – [7080-50-4].
Synonyms – N-chloro-p-toluene sulfonamide sodium salt trihydrate.
Molecular formula and molar mass – C7H7ClNNaO2S.3H2O – 281.69.
Description – Efflorescent white or slightly yellow crystals or crystalline powder.
Physical characteristic – Melting range: 167 °C to 170 °C.
Solubility – Freely soluble in water, soluble in ethyl alcohol with decomposition, insoluble in
benzene, chloroform and ethyl ether.
Conservation – In perfectly closed containers, protected from light, in a refrigerator.
Potassium chlorate
CAS – [3811-04-9].
Molecular formula and molar mass – KClO3 – 122.55.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Cobalt chloride
CAS – [7791-13-1].
Synonym – Cobalt(II) chloride.
Molecular formula and molar mass – CoCl2.6H2O – 237.93.
Specification – Contains no less than 99.0% (w/w).
Description – Crystalline powder or red-violet crystals.
Solubility – Very soluble in water and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Cobalt chloride RS
Specification – Contains 6.5 g of cobalt chloride, added with 70 mL of hydrochloric acid RS and
sufficient water to complete 100 mL.
Conservation – In tightly closed containers.
Acetyl chloride
CAS – [75-36-5].
Molecular formula and molar mass – C2H3CIO – 78.50.
Description – Clear and colorless liquid. Flammable. Decomposes in contact with water and with
ethyl alcohol.
Physical characteristics – Density (20 °C): approximately 1.10. Boiling temperature: 52 °C.
Miscibility – Miscible with ethylene chloride, ethyl ether and glacial acetic acid.
Conservation – In tightly closed containers.
Safety – Irritant to the eyes.
Aluminum chloride RS
Preparation – Dissolve two parts of aluminum chloride hexahydrate in water sufficient for three
parts. Treat the solution with activated charcoal, filter and, if necessary, adjust the pH to 1.5 with 1%
(w/v) sodium hydroxide.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Ammonium chloride
CAS – [12125-02-9].
Molecular formula and molar mass – NH4Cl – 53.49.
Specification – Contains no less than 99.5% (w/w) in relation to the desiccated substance.
Description – Colorless crystals or crystalline white powder, odorless, with salty flavor. Hygroscopic.
Physical characteristic – Sublimates without melting at 338 °C.
Solubility – Freely soluble in water.
Conservation – In hermetic containers. Storage – Protect from humidity.
Ammonium chloride RS
Specification – Contains 10.7 g in 100 mL of aqueous solution (approximately 2 M).
Conservation – In tightly closed containers.
Barium chloride
CAS – [10326-27-9].
Molecular formula and molar mass – BaCl2.2H2O – 244.27.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless crystals or white crystalline powder.
Solubility – Freely soluble in water and slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Toxic.
Barium chloride RS
Specification – Contains 10 g in 100 mL of aqueous solution.
Conservation – In tightly closed containers.
Benzalkonium chloride
CAS – [8001-54-5].
Molecular formula and molar mass – [C6H5CH2 N(CH3 )2R]+ Cl- – 360.00 (average)
Chemical composition – Mixture of alkyldimethylbenzylammonium chlorides, where R represents
alkyl, from n-C8H17 and superior homologs: n-C12H25, n-C14H29, n-C16H33, in higher proportion.
Specification – Contains no less than 95.0% in relation to the desiccated substance. Content of alkyl
homologs present, in relation to the total calculated over dried basis: n-C12H25: no less than 40.0%
(w/w); n-C14H29: no less than 10.0% (w/w); sum of the two homologs: no less than 70.0% (w/w).
Description – Amorphous powder or gelatinous white or yellow-white mass, of aromatic odor and
bitter flavor.
Solubility – Very soluble in water and in ethyl alcohol. In aqueous solution, it forms foam under
agitation.
Conservation – In tightly closed containers.
Storage – Protect from light and from air.
Category – Disinfectant. Detergent. Preservative.
Benzethonium chloride
CAS – [121-54-0].
Molecular formula and molar mass – C27H42ClNO2.H2O – 466.10.
Description – Colorless crystals or fine, white or nearly white powder.
Physical characteristic – Melting temperature: approximately 163 °C.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Benzyl chloride
CAS – [100-44-7].
Synonym – Chloromethyl benzene.
Molecular formula and molar mass – C7H7Cl – 126.58.
Description – Colorless liquid.
Physical characteristics – Density (20 °C): 1.100.
Boiling temperature: 179 °C. Melting range: -48 °C to -43 °C.
Solubility – Insoluble in water; miscible with ethyl alcohol, chloroform and ethyl ether.
Conservation – In hermetic containers.
Storage – Protect from heat.
Calcium chloride
CAS – [10043-52-4].
Molecular formula and molar mass – CaCl2 –110.98.
Specification – Contains no less than 98.0% (w/w) in relation to the desiccated substance.
Description – Dry, white granules. Deliquescent.
Solubility – Very soluble in water, freely soluble in ethyl alcohol and in methyl alcohol.
Conservation – In hermetic containers.
Storage – Protect from humidity.
Category – Desiccant.
Calcium chloride RS
Specification – Contains 7.35 g of calcium chloride in 100 mL of aqueous solution (approximately
0.5 M).
Conservation – In tightly closed containers.
Cesium chloride
CAS – [7647-17-8].
Molecular formula and molar mass – CsCl – 168.36.
Description – White or nearly white powder.
Solubility – Very soluble in water, freely soluble in methyl alcohol and practically insoluble in
acetone.
Tin(II) chloride RS
Preparation – Heat 20 g of tin with 85 mL of hydrochloric acid until no more hydrogen is released.
Magnesium chloride
CAS – [7791-18-6].
Molecular formula and molar mass – MgCl2 6H2O – 203.30.
Specification – Contains no less than 98.0% (w/w).
Description – Colorless crystals, with bitter flavor. Hygroscopic.
Solubility – Very soluble in water and freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Mercury(II) chloride
CAS – [7487-94-7].
Synonym – Mercuric chloride.
Molecular formula and molar mass – HgCl2 – 271.50.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Colorless crystals or white or nearly white crystalline powder, or crystallized mass;
odorless.
Physical characteristic – Melting temperature: 277 °C (volatilizes at temperature of approximately
300 °C).
Solubility – Soluble in water and in glycerol, freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – Irritant. Caustic. Toxic. Pollutant.
Additional information – Antidote: dimercaprol.
Methylene chloride
CAS – [75-09-2].
Synonym – Dichloromethane.
Molecular formula and molar mass – CH2Cl2 – 84.93.
Description – Clear, colorless, volatile liquid, with odor similar to chloroform.
Physical characteristics – Boiling temperature: approximately 40 °C.
Density: approximately 1.32. Refractive index (20 °C): 1.424.
Solubility – Moderately soluble in water; miscible with ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – Irritant. Toxic.
Methylthionine chloride
CAS – [7220-79-3].
Synonyms – Methylthionine chloride trihydrate, methylene blue.
Molecular formula and molar mass – C16H18ClN3S.3H2O – 373.90.
Description – Dark green or bronze crystalline powder. It may be found in different hydrate forms.
Solubility – Freely soluble in water and in ethyl alcohol.
Methylthionine chloride RS
Synonym – Methylene blue RS.
Preparation – Dissolve 23 mg of methylthionine chloride in sufficient amount of water to prepare
100 mL.
Nickel(II) chloride
CAS – [7791-20-0]
Molecular formula and molar mass – NiCl2.6H2O – 237.68.
Description – Green crystalline powder. Hygroscopic.
Nitrobenzoyl chloride
CAS – [122-04-3].
Molecular formula and molar mass – C7H4ClNO3 – 185.57.
Description – Yellow crystals, with pungent odor.
Physical characteristic – Melting temperature: approximately 73 °C.
Gold chloride
CAS – [16961-25-4].
Molecular formula and molar mass – HAuCl4.3H2O – 393.82.
Description – Red-yellow to golden yellow monoclinic crystals. Very hygroscopic and deliquescent.
Conservation – In tightly closed containers.
Storage – Protect from light.
Gold chloride RS
Preparation – Dissolve 1 g of gold chloride in 35 mL of water.
Conservation – In tightly closed containers.
Storage – Protect from light.
Palladium chloride
CAS – [7647-10-1].
Molecular formula and molar mass – PdCl2 – 177.32.
Specification – Contains no less than 59.0% (w/w) of palladium.
Description – Red-brown crystalline powder.
Physical characteristic – At high temperatures, decomposes to palladium and chlorine.
Conservation – In tightly closed containers.
Safety – Toxic.
Potassium chloride
CAS – [7447-40-7].
Molecular formula and molar mass – KCl – 74.55.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Colorless crystals or white crystalline powder, with saline, faintly bitter flavor.
Conservation – In tightly closed containers.
Sodium chloride
CAS – [7647-14-5].
Molecular formula and molar mass – NaCl – 58.44.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Colorless crystals or crystalline white powder, odorless, with saline flavor.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Tin chloride
CAS – [10025-69-1].
Molecular formula and molar mass – SnCl2.2H2O – 225.64.
Specification – Contains no less than 97.0% (w/w).
Description – Colorless or almost colorless crystals.
Solubility – Very soluble in water, freely soluble in ethyl alcohol, in glacial acetic acid, and in diluted
and concentrated hydrochloric acid.
Conservation – In tightly closed containers.
Storage – Protect from air and heat.
Tin chloride RS
Specification – Contains 10% (w/v) of tin chloride in hydrochloric acid.
Conservation – Prepare immediately before use.
Storage – Protect from light.
Ferric chloride
CAS – [10025-77-1].
Synonym – Iron chloride hexahydrate.
Molecular formula and molar mass – FeCl3.6H2O – 270.30.
Specification – Contains 99.0% (w/w) in relation to the desiccated substance.
Description – Orange-yellow or brown crystallized mass. Deliquescent.
Physical characteristic – Melting temperature: approximately 37 °C.
Conservation – In tightly closed containers.
Storage – Protect from light.
Platinic chloride RS
Synonym – Platinum chloride RS.
Preparation – Dissolve 2.6 g of chloroplatinic acid in water and complete the volume to 20 mL.
Conservation – In tightly closed containers.
Storage – Protect from light.
Benzoyl hydrochloride
CAS – [98-88-4].
Molecular formula and molar mass – C7H5ClO – 140.57.
Description – Colorless liquid. Decomposes in water and in ethyl alcohol.
Physical characteristics – Density (20 °C): approximately 1.21. Boiling temperature: approximately
197 °C.
(2-chloroethyl)dietylamine hydrochloride
CAS – [869-24-9].
Molecular formula and molar mass – C6H14ClN.HCl – 172.10.
Description – White crystalline powder.
Solubility – Very soluble in water and in methyl alcohol, freely soluble in methylene chloride,
practically insoluble in n-hexane.
Physical characteristic – Melting temperature: approximately 211 °C.
Dimethyl-p-phenylenediamine hydrochloride
CAS – [536-46-9].
Synonym – N,N-dimethyl-p-phenylenediamine dihydrochloride.
Molecular formula and molar mass – C8H12N2.2HCl – 209.12.
Description – White or nearly white crystalline powder. Hygroscopic.
Solubility – Freely soluble in water and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
O-phenylenediamine hydrochloride
CAS – [615-28-1].
Synonym – 1,2-benzenediamine dihydrochloride.
Molecular formula and molar mass – C6H8N2.2HCl – 181.06.
Description – White or slightly pink powder.
P-phenylenediamine hydrochloride
CAS – [624-18-0].
Synonym – 1,4-benzenediamine dihydrochloride.
Molecular formula and molar mass – C6H8N2.2HCl – 181.14.
Description – White crystalline powder, becomes reddish by exposure to air.
Solubility – Freely soluble in water, slightly soluble in ethyl alcohol and in ethyl ether.
Phenylhydrazine hydrochloride
CAS – [59-88-1].
Molecular formula and molar mass – C6H8N2.HCl – 144.60.
Description – White or nearly white crystalline powder, becomes brown by exposure to air.
Physical characteristic – Melting temperature: approximately 245 °C, with decomposition.
Solubility – Soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protected from light.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Phenylhydrazine hydrochloride RS
Preparation – Dissolve 0.9 g of phenylhydrazine hydrochloride in 50 mL of water. Decolor with
activated charcoal and filter. Collect the filtrate in a 250 mL volumetric flask, add 30 mL of
hydrochloric acid and complete the volume with water.
Hydrastine hydrochloride
CAS – [5936-28-7].
Molecular formula and molar mass – C21H22ClNO6 – 419.86.
Description – White or nearly white powder. Hygroscopic.
Physical characteristic – Rotation power (17 °C): approximately +127°. Melting temperature:
approximately 116 °C.
Solubility – Very soluble in water and in ethyl alcohol.
Hydroxylamine hydrochloride
CAS – [5470-11-1].
Molecular formula and molar mass – NH4ClO – 69.49.
Specification – Contains no less than 96.0% (w/w).
Description – Colorless crystals or white crystalline powder.
Physical characteristic – Melting temperature: approximately 151 °C.
Solubility – Very soluble in water and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Hydroxylamine hydrochloride RS
Preparation – Dissolve 5 g in 5 mL of hot water. Complete the volume to 100 mL with ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Flammable.
Chlorine RS
Specification – Saturated chlorine solution in water.
Conservation – In completely full and tightly closed containers.
Storage – In a cool place, protected from light and air.
Stability – Prepare the solution immediately before use.
Additional information – The solution tends to deteriorate even if protected from light and air.
p-Chloroacetanilide
CAS – [539-03-7].
Molecular formula and molar mass – C8H8ClNO – 169.61.
Description – Crystalline powder.
Physical characteristic – Melting temperature: approximately 178 °C.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Chlorobenzene
CAS – [108-90-7].
Molecular formula and molar mass – C6H5Cl – 112.56.
Description – Colorless, refringent liquid, with characteristic odor.
Physical characteristics – Boiling temperature: approximately 132 °C.
Density: approximately 1.11. Refractive index (20 °C): 1.5251.
Conservation – In tightly closed containers.
Safety – Toxic. Flammable.
1-Chloro-2,4-dinitrobenzene
CAS – [97-00-7].
Molecular formula and molar mass – C6H3ClN2O4 – 202.55.
Description – Pale yellow crystals or crystalline powder.
Physical characteristic – Melting temperature: approximately 51 °C.
Chloroform
Synonym – Trichloromethane.
Molecular formula and molar mass – CHCl3 – 119.37.
Specification – Contains no less than 99.9% (w/w).
Description – Mobile, colorless liquid, with sweet odor.
Physical characteristics – Density: approximately 1.48.
Boiling temperature: approximately 62 °C.
Conservation – In tightly closed containers.
Safety – Toxic.
Alcohol-free chloroform
Preparation – Prepare immediately before use. Shake, carefully, 20 mL of chloroform with 20 mL of
water for three minutes. Remove the organic phase carefully and wash with two portions of 20 mL of
water. Filter chloroform in dry paper. Add 5 g of anhydrous sodium sulfate, shake for five minute
and allow to stand for two hours. Decant or filter.
Chlorothiazide
CAS – [58-94-6].
Molecular formula and molar mass – C7H6ClN3O4S2 – 295.73.
Description – White or nearly white, odorless crystalline powder.
Physical characteristic – Melting temperature: approximately 340 °C, with decomposition.
Solubility – Very slightly soluble in water, moderately soluble in acetone, slightly soluble in ethyl
alcohol. Soluble in diluted alkali hydroxide solutions.
Sodium cobaltnitrite
CAS – [13600-98-1].
Molecular formula and molar mass – Na3CoN6O12 – 403.93.
Description – Orange-yellow crystalline powder.
Solubility – Freely soluble in water and slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers
Sodium cobaltnitrite RS
Specification – Contains 10 g of sodium cobaltnitrite in 100 mL of water.
Conservation – Prepare immediately before use.
Copper
CAS – [7440-50-8].
Element and atomic mass – Cu – 63.546.
Description – Slide, thread, powder or fragment, of reddish color and metallic luster.
Conservation – In non-metallic containers.
o-Cresol
CAS – [95-48-7].
Synonym – 2-Methylphenol.
Molecular formula and molar mass – C7H8O – 108.14.
Description – Colorless to brown-yellow liquid of solid, which acquires color by light and in the
presence of oxygen, of phenolic odor. Deliquescent.
Physical characteristics – Melting temperature: approximately 30 °C.
Boiling temperature: approximately 191 °C.
Density: approximately 1.03. Refractive index (20 °C): 1.540 – 1.550.
Solubility – Moderately soluble in water and soluble in alkali hydroxide solutions; miscible with ethyl
alcohol.
Conservation – In hermetic containers.
Storage – Protect from light, humidity and oxygen. Safety – Irritant. Caustic. Toxic.
Category – Disinfectant.
Potassium chromate
CAS – [7789-00-6].
Molecular formula and molar mass – K2CrO4 – 194.19.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Crystals or yellow crystalline powder.
Solubility – Freely soluble in water.
Conservation – In tightly closed containers.
Safety – Oxidizing agent. Pollutant.
Potassium chromate RS
Specification – Contains 10% (w/v) of potassium chromate in water.
Conservation – In tightly closed containers.
Safety – Oxidizing agent. Pollutant.
Disodium chromotropate
CAS – [5808-22-0].
Synonym – Chromotropic acid dihydrate disodium salt.
Molecular formula and molar mass – C10H6Na2O8S2.2H2O – 400.28.
Description – Yellow-white powder.
Solubility – Soluble in water and practically insoluble in ethyl alcohol.
Sodium deoxycholate
CAS – [302-95-4].
Molecular formula and molar mass – C24H39NaO4 – 414.56.
Description – White or nearly white crystalline powder.
Dextran
CAS – [9004-54-0]
Description – Powder.
Solubility – Soluble in water.
Dextran 5%
Preparation – Weigh 5 g of dextran and transfer to a 100 mL volumetric flask. Add distilled water in
sufficient amount for 100 mL. If possible, maintain the sterile solution using a sterilizing filtration
system with 0.22 µm pore filters.
Dextrose
Use glucose.
Chlorhexidine diacetate
Use chlorhexidine acetate.
1,8-Diaminonaphthalene
CAS – [479-27-6].
Synonym – 1,8-Naphthalenediamine.
Molecular formula and molar mass – C10H10N2 – 158.20.
Description – Sublimable crystals.
Physical characteristic – Melting range: 63 °C to 67 °C.
Diaveridine
CAS – [5355-16-8].
Synonym – 5-[(3,4-Dimethoxyphenyl)methyl]-2,4- pyrimidinediamine.
Molecular formula and molar mass – C13H16N4O2 – 260.30.
Physical characteristic – Melting temperature: approximately 233 °C.
2,6-Dibromoquinone-4-chlorimide
CAS – [537-45-1].
Molecular formula and molar mass – C6H2Br2ClNO – 299.35.
Description – Yellow crystalline powder.
Physical characteristic – Melting range: between 82 °C and 84 °C.
Solubility – Insoluble in water and soluble in ethyl alcohol and in diluted alkali hydroxide solutions.
Conservation – In closed containers.
Dibutylamine
CAS – [111-92-2].
Molecular formula and molar mass – C8H19N – 129.25.
Description – Colorless liquid.
Physical characteristics – Boiling temperature: approximately 159 °C.
Refractive index (20 °C): approximately 1.417.
Solubility – Soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Ethylene dichloride
CAS – [107-06-2].
Synonym – 1,2-Dichloroethane.
Molecular formula and molar mass – C2H4Cl2 – 98.96.
Description – Colorless and clear liquid, with odor similar to chloroform.
Physical characteristics – Boiling temperature: approximately 83 °C.
Density (20 °C): approximately 1.25. Refractive index (20 °C): 1.444.
Solubility – slightly soluble in water and freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Irritant. Toxic. Flammable.
N-(1-naphthyl)ethylenediamine dihydrochloride
CAS – [1465-25-4].
Synonyms – N-1-naphthalenyl-1,2- ethanediamine dihydrochloride.
Molecular formula and molar mass – C12H14N2.2HCl – 259.18.
Description – White or yellow-white powder.
Physical characteristic – Melting range: 188 °C to 190 °C.
Solubility – Soluble in water and slightly soluble in ethyl alcohol.
N-(1-naphthyl)ethylenediamine dihydrochloride RS
Synonym – Bratton-Marshall reagent.
Preparation – Dissolve 0.1 g of N-(1-naphthyl)ethylenediamine dihydrochloride in 100 mL of water.
Conservation – In tightly closed containers.
2,6-Dichloroquinone-4-chlorimide
CAS – [101-38-2].
Synonyms – Gibbs reagent, 2,6-diclhoro-4- (chloroimino)-2,5-cyclohexadien-1-one.
Molecular formula and molar mass – C6H2Cl3NO – 210.45.
Description – Orange or yellow crystalline powder.
Physical characteristic – Melting temperature: approximately 66 °C.
Solubility – Practically insoluble in water, soluble in ethyl alcohol and in diluted alkaline solutions.
Synonym – 1-(2,6-dichlorophenyl)indolin-2-one.
Molecular formula and molar mass – C14H9Cl2NO – 278.14.
Description – White crystalline powder.
Conservation – In tightly closed containers.
Storage – Protect from exposure to light.
2,6-Dichloroindophenol sodium
CAS – [620-45-1].
Synonym – 2,6-dichlorophenol-indophenol sodium.
Molecular formula and molar mass – C12H6Cl2NNaO2 – 290.08.
Description – Dark green powder. The aqueous solution presents a dark blue color and turns pink
when acidified.
Solubility – Freely soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Potassium dichromate
CAS – [7778-50-9].
Molecular formula and molar mass – K2Cr2O7 – 294.18.
Specification – Contains no less than 99.8% (w/w) in relation to the desiccated substance.
Description – Orange-red crystals. Odorless.
Solubility – Soluble in water and practically insoluble in ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Caustic. Oxidizing agent. Pollutant.
Potassium dichromate RS
Specification – Contains 5% (w/v) of potassium dichromate in water.
Conservation – In tightly closed containers.
Safety – Caustic. Oxidizing agent. Pollutant.
Diethylamine
CAS – [109-89-7].
Molecular formula and molar mass – C4H11N – 73.14.
Description – Clear, colorless, volatile liquid, with ammoniacal odor, strongly alkaline.
Physical characteristics – Boiling range: 55 °C to 58 °C. Refractive index (20 °C): 1.386.
Density (20 °C): approximately 0.707.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Irritant. Flammable.
Diethylaminoethyl-dextran
CAS – [9015-73-0].
Molecular formula and molar mass – C12H28N2O – 216.37.
Description – Powder.
Solubility – Soluble in water.
Silver diethyldithiocarbamate
CAS – [1470-61-7].
Molecular formula and molar mass – C5H10AgNS2 – 256.13.
Description – Light yellow to greyish-yellow powder.
Solubility – Practically insoluble in water and soluble in pyridine.
Conservation – In tightly closed containers.
Silver diethyldithiocarbamate RS
Specification – Contains 0.5% (w/v) of silver diethyldithiocarbamate in pyridine.
Stability – Prepare immediately before use.
Safety – Toxic.
Sodium diethyldithiocarbamate
CAS – [20624-25-3].
Molecular formula and molar mass – C5H10NNaS2.3H2O – 225.30.
Description – White, nearly white or colorless crystals.
Solubility – Freely soluble in water and soluble in ethyl alcohol.
N,N-diethyletilenediamine
CAS – [100-36-7].
Synonym – N,N-Diethyl-1,2-diaminoethane.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Diethyl phthalate
CAS – [84-66-2].
Molecular formula and molar mass – C12H14O4 – 222.24.
Description – Colorless and practically odorless oily liquid.
Specification – Contains no less than 99.0% (w/w).
Physical characteristics – Density: 1.118. Boiling temperature: 295 °C.
Miscibility – Miscible with water, ethyl alcohol, ethyl ether and other organic solvents. Conservation
– In tightly closed containers.
Safety – Irritant.
Diphenylamine
CAS – [122-39-4].
Molecular formula and molar mass – C12H11N – 169.23.
Description – White or nearly white crystals.
Physical characteristics – Melting temperature: approximately 55 °C. Boiling temperature: 302 °C.
Loses color in presence of light.
Solubility – Slightly soluble in water and soluble in ethyl alcohol. Forms salt in solution with strong
acids.
Conservation – In tightly closed containers.
Storage – Protect from light.
Diphenylamine RS
Preparation – Dissolve 1 g of diphenylamine in 100 mL of sulfuric acid.
Conservation – In tightly closed containers.
Storage – Protect from exposure to light.
Diphenylbenzidine
CAS – [531-91-9].
Synonym – N,N’-Diphenylbenzidine.
Molecular formula and molar mass – C24H20N2 – 336.44.
Description – White or slightly gray crystalline powder.
Physical characteristic – Melting temperature: approximately 248 °C.
Solubility – Practically insoluble in water, slightly soluble in ethyl alcohol.
Conservation – In closed containers.
Storage – Protect from exposure to light.
Aminoethanol diphenylborate
CAS – [524-95-8].
Molecular formula and molar mass – C14H16BNO – 225.10.
Description – White or yellow crystalline powder.
Physical characteristic – Melting temperature: approximately 193 °C.
Solubility – Practically insoluble in water and soluble in ethyl alcohol.
Aminoethanol diphenylborate RS
Preparation – Dissolve 1 g of aminoethanol diphenylborate in methyl alcohol and complete the
volume to 100 mL with the same solvent.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Diphenylcarbazide
CAS – [140-22-7].
Molecular formula and molar mass – C13H14N4O – 242.28.
Description – White crystalline powder; becomes pink by exposure to air.
Physical characteristic – Melting range: 168 °C to 171 °C.
Solubility – Very slightly soluble in water, soluble in acetone, in ethyl alcohol, and in glacial acetic
acid.
Conservation – In hermetic containers.
Storage – Protect from light and from air.
Diphenylcarbazide RS
Specification – Contains 1% (w/v) of diphenylcarbazide in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – Flammable.
Diphenylcarbazone
CAS – [538-62-5].
Molecular formula and molar mass – C13H12N4O – 240.27.
Description – Crystals with red-orange color.
Physical characteristic – Melting temperature: approximately 157 °C, with decomposition.
Solubility – Practically insoluble in water and freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Diphenylcarbazone-bromophenol blue RS
Preparation – In a 25 mL volumetric flask, dissolve 12 mg of diphenylcarbazone and 12.5 mg of
bromophenol blue in 15 mL of ethyl alcohol. Complete the volume with ethyl alcohol.
Conservation – Keep the solution in an amber glass container at temperature between 4 °C and 8 °C.
Mercuric diphenylcarbazone RS
Solution A – Dissolve 0.1 g of diphenylcarbazone in ethyl alcohol and complete the volume to 50 mL
with the same solvent.
Solution B – Dissolve 1 g of mercury(II) chloride in ethyl alcohol and complete the volume to 50 mL
with the same solvent.
Preparation – Mix equal volumes of Solutions A and B at the moment of using.
N,N’-Diisopropylethylenediamine
CAS – [4013-94-9]
Molecular formula and molar mass – C8H20N2 – 144.26.
Description – Colorless or yellow liquid. Corrosive, flammable and hygroscopic.
Physical characteristics – Density (20 °C): approximately 0.798. Refractive index (20 °C):
approximately 1.429. Boiling temperature: approximately 170 °C.
Dimethylacetamide
CAS – [127-19-5].
Molecular formula and molar mass – C4H9NO – 87.12.
Description – Colorless and clear liquid.
Physical characteristics – Boiling temperature: approximately 165 °C.
Refractive index (20 °C): approximately 1.437. Density (20 °C): approximately 0.94.
Miscibility – Miscible with water and with most organic solvents.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
p-Dimethylaminobenzaldehyde
CAS – [100-10-7].
Synonyms – 4-Dimethylaminobenzaldehyde and Ehrlich’s Reagent.
Molecular formula and molar mass – C9H11NO – 149.19.
Description – White to slightly yellow crystalline powder.
Physical characteristic – Melting temperature: approximately 74 °C.
Solubility – Soluble in ethyl alcohol and in diluted acid solutions.
Conservation – In tightly closed containers.
Storage – Protect from light.
p-Dimethylaminobenzaldehyde RS
Preparation – Dissolve, without heating, 0.2 g of p-dimethylaminobenzaldehyde in a mixture of
4.5 mL of water and 5.5 mL of hydrochloric acid. Prepare immediately before use.
p-Dimethylaminobenzaldehyde RS1
Preparation – Dissolve 0.2 g of p-dimethylaminobenzaldehyde in 20 mL of ethyl alcohol and add
0.5 mL of hydrochloric acid. Shake the solution with activated charcoal and filter. The solution color
is less intense than of a freshly prepared iodine solution at 0.0001 M. Use immediately after
preparation.
p-Dimethylaminobenzaldehyde RS2
Synonym – Wasicky Reagent.
Preparation – Dissolve 0.5 g of p-dimethylaminobenzaldehyde in 8.5 mL of sulfuric acid and
carefully add 8.5 mL of water.
4-(Dimethylamino)cinnamaldehyde
CAS – [6203-18-5].
Molecular formula and molar mass – C11H13NO – 175.23.
Description – Orange or orange-brown crystals or powder.
Physical characteristic – Melting temperature: approximately 138 °C.
Solubility – Soluble in ethyl alcohol, acetone and benzene.
2,6-Dimethylaniline
CAS – [87-62-7].
Synonym – 2,6-Xylidine.
Molecular formula and molar mass – C8H11N – 121.18.
Description – Colorless liquid.
Physical characteristic – Density (20 °C): approximately 0.98.
N,N-Dimethylaniline
CAS – [121-69-7].
Synonym – N,N-Dimethylbenzenamine.
Molecular formula and molar mass – C8H11N – 121.18.
Description – Clear, practically colorless oily liquid, turns dark during the storage.
Physical characteristic – Distillation range: 192 °C to 194 °C.
Solubility – Practically insoluble in water, freely soluble in ethyl alcohol and ethyl ether.
1,1-Dimethylethylamine
CAS – [75-64-9].
Synonym – tert-Butylamine.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
2,5-Dimethylphenol
CAS – [95-87-4].
Synonym – p-Xylenol.
Molecular formula and molar mass – C8H10O – 122.17.
Description – White or nearly white crystals.
Physical characteristic – Melting temperature: approximately 74.5 °C.
Dimethylformamide
CAS – [68-12-2].
Molecular formula and molar mass – C3H7NO – 73.10.
Description – Clear, colorless liquid, with odor similar to amines.
Physical characteristics – Boiling temperature: approximately 153 °C.
Density: approximately 0.95. Refractive index (20 °C): 1.424. 1.428.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Irritant. Toxic.
Dimethylsulfoxide
CAS – [67-68-5].
Synonym – DMSO.
Molecular formula and molar mass – C2H6OS – 78.13.
Description – Colorless and odorless liquid. Hygroscopic.
Physical characteristics – Boiling temperature: approximately 189 °C.
Density: approximately 1.10. Refractive index (20 °C): 1.424. 1.479.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from humidity and exposure to light.
Safety – Irritant.
1,3-Dinitrobenzene
CAS – [99-65-0].
Molecular formula and molar mass – C6H4N2O4 – 168.11.
Description – Yellow crystals.
Physical characteristic – Melting temperature: approximately 89 °C.
Solubility – Practically insoluble in water and slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers.
1,3-Dinitrobenzene RS
Specification – Contains 1% (w/v) of 1,3-dinitrobenzene in ethyl alcohol.
Conservation – Tightly closed container.
Dioxane
CAS – [123-91-1].
Synonyms – 1,4-Dioxane, ethylene dioxide, dioxane.
Molecular formula and molar mass – C4H8O2 – 88.11.
Description – Clear, colorless liquid, with odor similar to ethyl ether.
Physical characteristics – Boiling temperature: approximately 101 °C.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Sulfur dioxide
CAS – [7446-09-5].
Synonym – Sulfur anhydride.
Molecular formula and molar mass – SO2 – 64.06.
Specification – Contains no less than 97.0% (v/v).
Description – Colorless gas, with characteristic, suffocating odor.
Conservation – In pressurized cylinders.
Safety – Irritant. Toxic.
Manganese dioxide
CAS – [1313-13-9].
Molecular formula and molar mass – MnO2 – 86.94.
Description – Black or dark brown fine powder.
Conservation – In tightly closed containers.
Storage – Protect from heat.
Safety – Energetic oxidizing agent.
Dipropylene glycol
CAS – [25365-71-8].
Synonym – 1,1’-Oxide-2-propanol.
Molecular formula and molar mass – C6H14O3 – 134.18.
Description – Colorless, practically odorless liquid.
Physical characteristics – Density: approximately 1.02. Boiling temperature: approximately 230 °C.
Conservation – In tightly closed containers.
Storage – In properly ventilated places.
Carbon disulfide
CAS – [75-15-0].
Molecular formula and molar mass – CS2 – 76.14.
Description – Colorless or yellow liquid.
Physical characteristics – Density (20 °C): approximately 1.26. Boiling range: 46 °C to 47 °C.
Solubility – Practically insoluble in water and miscible with ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Poisonous! Flammable.
Dithiol
CAS – [496-74-2].
Synonyms – 1,2-Dimercapto-4-methylbenzene; toluene-3,4-dithiol.
Molecular formula and molar mass – C7H8S2 – 156.27.
Description – White or nearly white crystals.
Physical characteristic – Melting temperature: 31 °C.
Solubility – Soluble in methyl alcohol and in alkali hydroxide solutions.
Dithiol RS
Specification – Contains 0.5 g of dithiol in 100 mL of ethyl alcohol.
Stability – Prepare immediately before use.
Safety – Flammable.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Dithiothreitol
CAS – [3483-12-3].
Molecular formula and molar mass – C4H10O2S2 – 154.24.
Description – White crystals.
Solubility – Freely soluble in water, in acetone and in ethyl alcohol.
Conservation – In tightly closed containers.
Dithizone
CAS – [60-10-6].
Synonym – Diphenylthiocarbazone.
Molecular formula and molar mass – C13H12N4S – 256.33.
Specification – Contains no less than 98.0% (w/w).
Description – Dark brown crystalline powder.
Physical characteristic – Melting temperature: 168 °C, with decomposition.
Solubility – Practically insoluble in water and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from exposure to light.
Dithizone RS
Specification – Contains 0.05% (w/v) of dithizone in carbon tetrachloride.
Conservation – In hermetic containers.
Storage – Protect from heat.
Safety – Poison!
Disodium edetate
CAS – [6381-92-6].
Synonyms – EDTA disodium; Disodium salt, dihydrate, of (ethylenedinitrilo)acetic acid
Molecular formula and molar mass – C10H14N2Na2O8.2H2O – 372.24.
Specification – Contains no less than 97.0% (w/w) in relation to the desiccated substance.
Description – White crystalline powder, of faint saline flavor.
Solubility – Soluble in water and practically insoluble in ethyl alcohol.
Conservation – In tightly closed containers.
Category – Chelating agent.
Specification – Contains 1.861 g, added with 10 mL of sodium hydroxide M, and dilute in water to
100 mL.
Conservation – In tightly closed containers.
Emodin
CAS – [518-82-1]
Molecular formula and molar mass – C15H10O5 – 270.25
Description – Orange-red needles.
Solubility – Practically insoluble in water, soluble in ethyl alcohol and in alkali hydroxide solutions.
Sulfur
CAS – [7704-34-9]
Element and atomic mass – S – 32.1
Description – Fine grayish yellow or greenish yellow powder.
Aescin
CAS – [11072-93-8]
Specification – Mixturt of saponins obtained from Aesculus hippocastanum L. seeds.
Description – Amorphous, fine, nearly white, red or yellow powder.
Metallic tin
CAS – [7440-31-5]
Element and atomic mass – Sn – 118.71
Specification – Purity of no less than 99.5%.
Description – Gray granules.
Physical characteristic – Melting temperature: approximately 231.9 °C.
Conservation – In tightly closed containers.
Storage – Protect from exposure to light and from heat.
Safety – Irritant.
Methyl stearate
CAS – [112-61-8]
Molecular formula and molar mass – C19H38O2 – 298.50
Description – White crystals or white or pale yellow crystalline mass.
Physical characteristic – Melting temperature: approximately 38 °C.
Solubility – Soluble in ethyl alcohol and petroleum ether.
Conservation – In tightly closed containers.
Erythromycin estolate
CAS – [3521-62-8]
Molecular formula and molar mass – C52H97NO18S – 1056.43.
Physical characteristic – Melting range: 135 °C to 138 °C.
Solubility – Practically insoluble in water, freely soluble in ethyl alcohol, soluble in acetone. It is
practically insoluble in diluted hydrochloric acid.
Conservation – In hermetic containers.
Storage – Protect from light and heat.
Therapeutic class – Antibacterial.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Petroleum ether
CAS – [8032-32-4].
Synonym – Benzine.
Description – Clear, colorless, volatile liquid, with characteristic odor. Non-fluorescent.
Physical characteristics – Boiling range: 40 °C to 60 °C. Density: 0.630 to 0.656.
Solubility – Practically insoluble in water; miscible with ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from heat.
Safety – Flammable.
Ethyl ether
CAS – [60-29-7].
Molecular formula and molar mass – C4H10O – 74.12
Specification – Contains no less than 96.0% (v/v).
Description – Clear, colorless, very volatile liquid, with characteristic pungent odor.
Hygroscopic. Physical characteristics – Boiling temperature: approximately 35 °C. Density:
approximately 0.715. Refractive index (20 °C): 1.355.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light and from heat (do not exceed the temperature of 15 °C).
Category – Anesthetic.
Safety – Flammable. Risk of explosion.
Isopropyl ether
CAS – [108-20-3].
Synonym – Diisopropyl ether.
Molecular formula and molar mass – C6H14O – 102.18.
Description – Colorless and clear liquid.
Physical characteristics – Boiling range: 67 °C to 69 °C. Density (20 °C): 0.723 to 0.728.
Solubility – Very slightly soluble in water; miscible with ethyl alcohol.
Conservation – In closed containers.
Storage – Protect from light.
Safety – Flammable.
Ethylene glycol
CAS – [107-21-1].
Synonym – 1,2-Ethanediol.
Molecular formula and molar mass – C2H6O2 – 62.07.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Ethylparaben
CAS – [120-47-8].
Molecular formula and molar mass – C9H10O3 – 166.18.
Description – Small and colorless crystals or white powder.
Physical characteristics – Melting temperature: 116 °C. Boiling range: 297 °C to 298 °C, with
decomposition.
Solubility – Slightly soluble in water, freely soluble in acetone, ethyl alcohol and ethyl ether.
Conservation – In closed containers.
Category – Preservative.
Eugenol
CAS – [97-53-0].
Molecular formula and molar mass – C10H12O2 – 164.20.
Description – Colorless or slightly yellow oily liquid. Gets dark and becomes more viscous with the
exposure to light and contact with air.
Physical characteristics – Density (20 °C): approximately 1.07. Boiling temperature: approximately
250 °C.
Solubility – Practically insoluble in water; miscible with ethyl alcohol, fatty oils and essential oils.
1,10-Phenanthroline
CAS – [5144-89-8].
Synonym – Orthophenanthroline.
Molecular formula and molar mass – C12H8N2.H2O – 198.23.
Description – White crystalline powder.
Physical characteristic – Melting range: 100 °C to 104 °C.
Solubility – Slightly soluble in water, soluble in acetone and in ethyl alcohol.
Category – Indicator for redox systems; reagent for colorimetry.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
DL-Phenylalanine
CAS – [150-30-1].
Molecular formula and molar mass – C9H11NO2 – 165.19.
Specification – Contains no less than 99.0%.
Description – Monoclinic crystals.
Physical characteristic – Sublimates in vacuum.
Phenol
CAS – [108-95-2].
Molecular formula and molar mass – C6H6O – 94.11.
Specification – Contains no less than 98.0% (w/w).
Description – Crystalline mass or colorless, faintly pink or yellow crystals, with characteristic odor.
Deliquescent.
Physical characteristics – Melting temperature: approximately 43 °C. Boiling temperature:
approximately 180 °C.
Solubility – Soluble in water, very soluble in ethyl alcohol, in glycerol and in methylene chloride.
Conservation – In hermetic containers.
Storage – Protect from light and from heat.
Labeling – It must indicate the name and amount of stabilizer.
Category – Disinfectant.
Safety – Caustic. Toxic.
Phenolphthalein
CAS – [77-09-8].
Molecular formula and molar mass – C20H14O4 – 318.33.
Specification – Contains no less than 97.0% (w/w) in relation to the desiccated substance.
Description – Crystalline or amorphous powder, white or slightly yellow. Odorless.
Physical characteristic – Melting temperature: approximately 258 °C.
Solubility – Practically insoluble in water and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Category – Acid-base indicator.
2-Phenoxyethanol
CAS – [122-99-6].
Molecular formula and molar mass – C8H10O2 – 138.17.
Description – Colorless, slightly viscous liquid, with faint aromatic odor and ardent flavor.
Physical characteristics – Density (20 °C): approximately 1.11. Boiling temperature: approximately
245 °C. Refractive index (20 °C): 1.534.
Solubility – Slightly soluble in water, freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Category – Preservative.
Potassium ferricyanide
CAS – [13746-66-2].
Molecular formula and molar mass – K3Fe(CN)6 – 329.25.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Specification – Contains no less than 99.9% (w/w) in relation to the desiccated substance.
Description – Red crystals.
Solubility – Freely soluble in water. Conservation – In tightly closed containers.
Storage – Protect from light.
Potassium ferricyanide RS
Specification – Contains 5% (w/v) of potassium ferricyanide in water.
Conservation – Prepare immediately before use.
Storage – Protect from light.
Potassium ferricyanide
CAS – [14459-95-1].
Molecular formula and molar mass – K4Fe(CN)6.3H2O – 422.39.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Clear crystals or yellow crystalline powder. Efflorescent. Becomes anhydrous at 100
°C.
Solubility – Freely soluble in water and practically insoluble in ethyl alcohol.
Conservation – In tightly closed containers.
Potassium ferricyanide RS
Specification – Contains 5.3% (w/v) of potassium ferricyanide in water (approximately 0.125
M).
Conservation – Prepare immediately before use.
Fibrinogen
CAS – [9001-32-5].
Refer to the Lyophilized human fibrinogen monograph.
Phloroglucin RS
Preparation – Dissolve 1 g of phloroglucinol in ethyl alcohol and dilute to 100 mL with the same
solvent.
Conservation – In tightly closed containers.
Storage – Protect from light.
Phloroglucinol
CAS – [6099-90-7].
Molecular formula and molar mass – C6H6O3.2H2O – 162.14.
Description – White or light yellow crystals or crystalline powder.
Solubility – Slightly soluble in water and soluble in ethyl alcohol and ethyl ether.
Ammonium fluoride
CAS – [12125-01-8].
Molecular formula and molar mass – NH4F – 37.04.
Description – Colorless crystals.
Physical characteristic – Melting temperature: approximately 100 °C.
Conservation – Protect from light, heat and humidity.
Safety – Irritant.
Calcium fluoride
CAS – [7789-75-5].
Molecular formula and molar mass – CaF2 – 78.07.
Description – White crystals or powder.
Conservation – In tightly closed containers.
Sodium fluoride
CAS – [7681-49-4].
Molecular formula and molar mass – NaF – 41.99.
Description – Colorless crystals or white or nearly white powder.
Physical characteristics – Density: 2.78. Melting temperature: 993 °C.
Solubility – Soluble in water and practically insoluble in ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Poisonous!
Sodium fluoride RS
Preparation – Dry approximately 0.5 g of sodium fluoride at temperature of 200 °C for four hours.
Weigh, accurately, about 0.222 g of dry material, dissolve in water and complete the volume to
100 mL with the same solvent. Pipette 10 mL of this solution, transfer to a 1000 mL volumetric flask
and complete the volume with water. Each mL of this solution is equivalent to 10 μg of fluorine.
Conservation – In tightly closed containers.
Formaldehyde, solution
Synonyms – Formol, formalin.
Molecular formula and molar mass – CH2O – 30.03.
Specification – Contains no less than 34.0% (w/v) and no more than 37.0% (w/v).
Description – Colorless, clear liquid. Produces irritant vapors.
Physical characteristics – Density: approximately 1.08. Refractive index (20 °C): 1.374.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Formamide
CAS – [75-12-7].
Molecular formula and molar mass – CH3NO – 45.04.
Description – Clear, colorless, viscous liquid, with faint ammoniacal odor.
Physical characteristics – Boiling temperature: approximately 210 °C. Density (20 °C):
approximately 1.13. Refractive index (20 °C): 1.447.
Conservation – In hermetic containers.
Storage – Protect from humidity.
Safety – Irritant.
Ammonium formate
CAS – [540-69-2].
Molecular formula and molar mass – CH5NO2 – 63.06.
Description – Deliquescent granules and crystals.
Physical characteristic – Melting range: between 119 °C and 121 °C.
Solubility – Very soluble in water and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Codeine phosphate
CAS – [41444-62-6].
Synonym – Codeine phosphate hemihydrate.
Molecular formula and molar mass – C18H21NO3.H3PO4.1/2H2O – 406.37.
Description – White or nearly white crystalline powder, or small colorless crystals.
Solubility – Freely soluble in water. Slightly or very slightly soluble in ethyl alcohol.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Potassium phosphate
CAS – [7778-53-2].
Synonym – Potassium phosphate tribasic.
Molecular formula and molar mass – K3PO4 – 212.27.
Description – White crystals or crystalline, deliquescent powder.
Solubility – Soluble in water and insoluble in ethyl alcohol.
Conservation – In tightly closed containers.
Tetrabutylammonium phosphate
CAS – [5574-97-0].
Molecular formula and molar mass – C16H38NO4P – 339.46.
Description – White or nearly white powder. Hygroscopic.
Solubility – Soluble in water.
Conservation – In closed containers.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Tributyl phosphate
CAS – [126-73-8].
Molecular formula and molar mass – C12H27O4P – 266.32.
Description – Colorless or slightly yellow, odorless liquid.
Solubility – Slightly soluble in water.
Red phosphorus
CAS – [7723-14-0].
Description – Dark red powder.
Solubility – Insoluble in water and in diluted acids.
Safety – Flammable.
Fructose
CAS – [57-48-7].
Synonyms – β-D-Fructose, levulose.
Molecular formula and molar mass – C6H12O6 – 180.16.
Specification – Contains no less than 98.0% (w/w) in relation to the desiccated substance.
Description – White, odorless crystalline powder, with strong sweet flavor.
Physical characteristic – Melting temperature with decomposition: approximately 103 °C.
Solubility – Very soluble in water and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Phthalaldehyde
CAS – [643-79-8].
Molecular formula and molar mass – C8H6O2 – 134.13.
Description – Yellow crystalline powder.
Physical characteristic – Melting temperature: approximately 55 °C.
Conservation – In closed containers.
Storage – Protect from exposure to light and from contact with air.
Dibutyl phthalate
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
CAS – [84-74-2].
Synonyms – Phthalic acid dibutyl ester, di-n-butyl phthalate and phthalate dibutyl.
Molecular formula and molar mass – C16H22O4 – 278.35.
Description – Colorless or slightly colored clear, oily liquid.
Physical characteristics – Boiling temperature: 340 °C. Density: 1.043 to 1.048.
Solubility – Very slightly soluble in water, very soluble in acetone, ethyl alcohol and ethyl ether.
Phthalazine
CAS – [253-52-1].
Molecular formula and molar mass – C8H6N2 – 130.15
Description – Pale yellow crystals.
Physical characteristic – Melting range: between 90 °C and 91 °C.
Solubility – Freely soluble in water and soluble in absolute ethyl alcohol, in ethyl acetate and in
methyl alcohol.
Bleached fuchsine RS
Synonym – Schiff’s Reagent.
Preparation – Dissolve 1 g of basic fuchsine in 600 mL of water, add 100 mL of 10% (w/v) sodium
sulfite. Cool down externally with ice, under agitation. Slowly add 10 mL of hydrochloric acid, dilute
with water to 1000 mL and filter. If the solution gets dark, shake with 0.2 to 0.3 g of activated charcoal
until bleaching and filter immediately. If the pink color still remains, add 2 to 3 mL of hydrochloric
acid and shake.
Conservation – Allow to stand for one hour before use, keep protected from light.
Galactose
CAS – [59-23-4].
Molecular formula and molar mass – C6H12O6 – 180.16.
Description – White crystalline powder.
Physical characteristic – Melting temperature: 167 °C.
Solubility – Freely soluble in water.
Conservation – In tightly closed containers.
Gelatin
CAS – [9000-70-8].
Glycerol gelatin
Preparation – Dissolve 1 g of gelatin in 100 mL of water heated at temperature not superior to 30 °C.
Add 1 mL of 2% (w/v) sodium salicylate and 15 mL of glycerol; shake and filter the heated mixture
in glass wool.
Gelatin RS
Preparation – Dissolve 2.5 g of gelatin in 100 mL of hot water. Use after cooling down to room
temperature.
Glycerol
CAS – [56-81-5].
Synonym – Glycerin.
Molecular formula and molar mass – C3H8O3 – 92.09.
Specification – Contains no less than 97.0% (w/w).
Description – Clear, colorless, odorless, hygroscopic, viscous liquid, with sweet flavor.
Physical characteristics – Density: 1.255 to 1.263. Refractive index (20 °C): 1.470 to 1.474.
Solubility – Miscible with water and with ethyl alcohol; slightly soluble in acetone and practically
insoluble in fatty oils and essential oils.
Conservation – In hermetic containers.
Storage – Protect from oxidizing agent.
Glycine
CAS – [56-40-6].
Molecular formula and molar mass – C2H5NO2 – 75.07.
Description – White and odorless crystalline powder.
Physical characteristic – Melting range: 232 °C to 236 °C, with decomposition.
Solubility – Freely soluble in water, slightly soluble in ethyl alcohol and very slightly soluble in ethyl
ether.
Glucose
CAS – [50-99-7].
Synonym – Dextrose.
Molecular formula and molar mass – C6 H12O6 – 180.16.
Description – White, odorless crystalline powder, with sweet flavor.
Physical characteristic – Specific rotation power (20 °C): + 52.5° to + 53.0° (dissolve 10 g of glucose
in 100 mL of water and add 0.2 mL of ammonia).
Solubility – Freely soluble in water and moderately soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Glyoxal-hydroxyanil
CAS – [1149-16-2].
Synonym – Glyoxal di(2-hydroxyanil).
Molecular formula and molar mass – C14H12N2O2 – 240.26.
Description – White or nearly white crystals.
Physical characteristic – Melting temperature: approximately 200 °C. Solubility – Soluble in hot
ethyl alcohol.
Glutaraldehyde
CAS – [111-30-8].
Molecular mass formula – C5H8O2 – 100.12.
Description – Oily liquid.
Physical characteristics – Refractive index (25 °C): approximately 1.434. Boiling temperature:
approximately 188 °C.
Miscibility – Miscible with water.
Guaiacol
CAS – [95-05-1].
Synonym – 2-methoxyphenol, methylcatechol.
Molecular formula and molar mass – C7H8O2 – 124.14.
Description – White or slightly yellow crystals, or colorless or slightly yellow liquid. Hygroscopic.
Physical characteristics – Melting temperature: approximately 28 °C. Boiling temperature:
approximately 205 °C.
Solubility – Slightly soluble in water, very soluble in methylene chloride and freely soluble in ethyl
alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light.
Guanine
CAS – [73-40-5].
Molecular formula and molar mass – C5H5N5O – 151.13.
Description – White or nearly white amorphous powder.
Solubility – Practically insoluble in water, slightly soluble in ethyl alcohol. Dissolves in diluted alkali
hydroxide solutions.
Heparin sodium
CAS – [9041-08-1].
Description – Consists of mixing active ingredients, with the property of extending the blood
coagulation time. Usually obtained from the intestinal mucosa, lungs or another adequate tissue from
domestic mammals used for human consumption.
Solubility – Freely soluble in water.
Conservation – In hermetic containers.
Labeling – The label must include the organ and species of origin. The potency must be indicated in
IU.
Therapeutic class – Anticoagulant.
Heptane
Specification – Usually contains a mixture of hydrocarbons – fraction of petroleum – with
predominance of n-heptane.
Description – Clear, colorless, volatile, highly flammable liquid, with characteristic odor. Physical
characteristics – Boiling range: 95 °C to 99 °C. Density: approximately 0.69. Solubility – Practically
insoluble in water and miscible with absolute ethyl alcohol. Miscible with ethyl ether, chloroform,
benzene and with the majority of volatile and non-volatile oils.
Conservation – In hermetic containers.
Storage – Protect from heat. Keep away from flame/spark.
Safety – Irritant to the respiratory tract. Flammable.
n-Heptane
CAS – [142-82-5].
Molecular formula and molar mass – C7H16 – 100.21.
Specification – Main component of heptane.
Description – Clear and flammable liquid.
Physical characteristics – Boiling temperature: 98.4 °C. Density: 0.684. Refractive index (20 °C):
1.3855.
Solubility – Practically insoluble in water; miscible with absolute ethyl alcohol.
Sodium heptanesulfonate
CAS – [22767-50-6].
Molecular formula and molar mass – C7H15NaO3S – 202.25.
Description – White or nearly white crystalline mass.
Solubility – Freely soluble in water and soluble in methyl alcohol.
Conservation – In hermetic containers.
Hexane
Specification – Usually contains a mixture of C6H14 isomers, predominantly n-hexane and
methylcyclopentane (C6H12).
Description – Clear, colorless, volatile, highly flammable liquid, with characteristic odor.
Physical characteristics – Boiling range: 67 °C to 70 °C. Density: 0.66.
Conservation – In hermetic containers.
Storage – Protect from heat. Keep away from flame/spark.
Safety – Irritant to the respiratory tract. Flammable.
n–Hexane
CAS – [110-54-3].
Molecular formula and molar mass – C6H14 – 86.18.
Specification – Main component of petroleum ether and hexane.
Description – Clear, volatile liquid, with odor similar to petroleum.
Physical characteristics – Boiling temperature: 69 °C. Density: 0.66. Refractive index (20 °C): 1.375.
Solubility – Practically insoluble in water; miscible with absolute ethyl alcohol.
Conservation – In hermetic containers.
Storage – Protect from heat. Keep away from flame/spark.
Safety – Flammable.
1- Sodium hexanesulfonate
CAS – [2832-45-3].
Molecular formula and molar mass – C6H13NaO3S – 188.22.
Description – White or nearly white powder.
Hexylamine
CAS – [111-26-2].
Synonym – Hexanamine.
Formula and molar mass – C6H15N – 101.19.
Description – Colorless liquid.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Physical characteristics – Density (20 °C): approximately 0.766. Refractive index (20 °C):
approximately 1.418. Boiling temperature: 127 °C to 131 °C.
Solubility – Slightly soluble in water and soluble in ethyl alcohol.
Chloral hydrate
CAS – [302-17-0].
Synonym – Hydrated chloral.
Molecular formula and molar mass – C2H3Cl3O2 – 165.40.
Specification – Contains no less than 98.5% (w/w).
Description – Clear, colorless crystals, with characteristic pungent odor and slightly bitter, caustic
taste. Deliquescent.
Physical characteristic – Melting temperature: 57 °C.
Solubility – Very soluble in water and freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light and from heat. Safety – Irritant to the skin.
Therapeutic class – Sedative, hypnotic.
Hydrazine, hydrate
CAS – [7803-57-8].
Molecular formula and molar mass – N2H4.H2O – 50.06.
Description – Colorless and clear liquid.
Miscibility – Miscible with water.
Conservation – In tightly closed containers.
Ammonium hydroxide
Use ammonia, concentrated solution.
Barium hydroxide
CAS – [12230-71-6].
Molecular formula and molar mass – Ba(OH)2.8H2O – 315.46.
Description – Colorless crystals.
Physical characteristic – Melting temperature: 78 °C.
Solubility – Soluble in water.
Conservation – In tightly closed containers.
Calcium hydroxide
CAS – [1305-62-0].
Molecular formula and molar mass – Ca(OH)2 – 74.09.
Specification – Contains no less than 93.0% (w/w).
Description – White, soft, odorless granules or powder.
Solubility – Practically insoluble in water.
Conservation – In tightly closed containers.
Storage – Protect from carbon dioxide.
Calcium hydroxide RS
Specification – Contains 0.15 g of calcium hydroxide in 100 mL of preparation with carbon dioxide-
free water (saturated solution).
Conservation – In tightly closed containers.
Lithium hydroxide
CAS – [1310-66-3].
Molecular formula and molar mass – LiOH.H2O – 41.96.
Description – White or nearly white granular powder.
Solubility – Soluble in water, forming a strongly alkaline solution. Moderately soluble in ethyl
alcohol.
Conservation – In tightly closed containers.
Safety – Corrosive.
Potassium hydroxide
CAS – [1310-58-3].
Molecular formula and molar mass – KOH – 56.11.
Specification – Contains no less than 85.0% (w/w), calculated as KOH, and no more than 3.5% of
K2CO3.
Description – White, hard, dry mass, with crystalline, odorless and very hygroscopic structure.
Absorbs carbon dioxide. Liquefies on air. Presented in form of pellets, cylinders or scales.
Solubility – Very soluble in water and freely soluble in ethyl alcohol.
Conservation – In hermetic , inert containers.
Storage – Protect from humidity and from carbon dioxide. Safety – Very caustic.
Sodium hydroxide
CAS – [1310-73-2].
Synonym – Caustic soda.
Molecular formula and molar mass – NaOH – 40.00.
Specification – Contains no less than 95.0% (w/w) total alkali, calculated as NaOH, and no more than
3.0% (w/w) Na2CO3.
Description – White hard mass, with crystalline structure, in the form of flakes, pellets and sticks.
Deliquescent and absorbs carbon dioxide.
Solubility – Very soluble in water and freely soluble in ethyl alcohol.
Conservation – In hermetic containers.
Storage – Protect from humidity and from carbon dioxide.
Safety – Caustic, corrosive.
Sodium hydroxide RS
Specification – Contains 8% (w/v) of sodium hydroxide in water.
Conservation – Refer to sodium hydroxide M.
Sodium hydroxide M
Specification – Contains 40 g of sodium hydroxide in 1000 mL of preparation with carbon dioxide-
free water.
Conservation – In alkali-resistant glass or polyethylene containers.
Storage – Protect from humidity and from carbon dioxide.
Tetrabutylammonium hydroxide
CAS – [2052-49-5].
Molecular formula and molar mass – (C4H9)4NOH – 259.48.
Description – White or nearly white crystals.
Solubility – Soluble in water.
Tetramethylammonium hydroxide
CAS – [75-59-2].
Molecular formula and molar mass – C4H13NO – 91.15.
Description – It is a stronger base than ammonia and quickly absorbs carbon dioxide from air. A
preparation in aqueous medium at 25% (w/v) is clear and colorless.
Physical characteristic – Melting temperature: 63 °C.
Conservation – In tightly closed containers.
Tetramethylammonium hydroxide RS
Specification – Contains no less than 10% (w/w) tetramethylammonium hydroxide.
Description – Colorless or light yellow clear liquid.
Miscibility – Miscible with water and ethyl alcohol.
Preparation – To 1.000 g, add 50 mL of water and titrate with sulfuric acid 0.05 M VS, using 0.1 mL
of methyl red TS as indicator. Each mL of sulfuric acid 0.05 M VS is equivalent to 9.12 mg of
C4H13NO.
D-α-4-hydroxyphenylglycine
CAS – [22818-40-2].
Molecular formula and molar mass – C8H9NO3 – 167.16.
Description – Brilliant leaflets.
Physical characteristic – Decomposition range: between 220 °C and 247 °C.
Solubility – Moderately soluble in water, in ethyl alcohol, ethyl ether and acetone. Soluble in alkaline
and acid minerals.
Hydroxymethylfurfural
CAS – [67-47-0].
Synonym – 5-Hydroxymethylfurfural.
Molecular formula and molar mass – C6H6O3 – 126.11.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Hydroxiquinoline
CAS – [148-24-3].
Synonym – 8-hydroxyquinoline.
Molecular formula and molar mass – C9H7NO – 145.16.
Description – White or slightly yellow crystalline powder.
Physical characteristic – Melting temperature: approximately 75 °C.
Solubility – Slightly soluble in water, freely soluble in acetone, in ethyl alcohol and in diluted mineral
acid solutions.
Butylated hydroxytoluene
CAS – [128-37-0].
Synonym – BHT.
Molecular formula and molar mass – C15H24O – 220.36.
Specification – Contains no less than 99.0% (w/w).
Description – White or yellow-white crystalline powder.
Physical characteristics – Freezing temperature: no less than 69.2 °C. Boiling temperature: 265 °C.
Density: 1.048.
Solubility – Practically insoluble in water, very soluble in acetone, freely soluble in ethyl alcohol and
in vegetable oils.
Safety – May cause contact dermatitis.
Hyperoside
CAS – [482-36-0].
Molecular formula and molar mass – C21H20O12 – 464.38.
Description – Pale yellow needles.
Physical characteristic – Melting temperature: approximately 240 °C, with decomposition.
Solubility – Soluble in methyl alcohol.
Sodium hypochlorite
CAS – [7681-52-9].
Molecular formula and molar mass – NaClO – 74.44.
Description – White crystals. It is usually obtained in the pentahydrate form, and its anhydrous form
is explosive.
Physical characteristic – Melting temperature: 18 °C (pentahydrate form).
Solubility – Very soluble in water.
Conservation – In tightly closed containers. Safety – Irritant.
Sodium hypochlorite RS
Refer to the Diluted sodium hypochlorite solution monograph.
Sodium hypophosphite
CAS – [10039-56-2].
Molecular formula and molar mass – NaH2PO2.H2O – 105.99.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – White granulated or crystalline powder or colorless, odorless crystals, with saline
flavor. Hygroscopic.
Solubility – Freely soluble in water and soluble in ethyl alcohol.
Sodium hypophosphite RS
Specification – Contains 5 g of sodium hypophosphite in 10 mL of water, added to 50 mL with
hydrochloric acid. Separate eventual crystals formed. The solution must be clear and colorless.
Imidazole
CAS – [288-32-4].
Synonym – Glyoxaline.
Molecular formula and molar mass – C3H4N2 – 68.08.
Description – White crystalline powder.
Physical characteristic – Melting range: 90 °C to 91 °C.
Solubility – Soluble in water and in ethyl alcohol.
Iminodibenzyl
CAS – [494-19-9].
Molecular formula and molar mass – C14H13N – 195.27.
Description – Pale yellow crystalline powder.
Physical characteristic – Melting temperature: approximately 106 °C.
Solubility – Practically insoluble in water and freely soluble in acetone.
Conservation – In tightly closed containers.
Inosine
CAS – [58-63-9].
Molecular formula and molar mass – C10H12N4O5 – 268.23.
Physical characteristic – Melting temperature: 222 °C to 226 °C.
Potassium iodate
CAS – [7758-05-6].
Molecular formula and molar mass – KIO3 – 214.00.
Description – White, odorless crystals or crystalline powder.
Physical characteristic – Melting temperature: approximately 560 °C, with partial decomposition.
Solubility – Soluble in water, insoluble in ethyl alcohol.
Category – Oxidizing agent.
Mercury(II) iodide
CAS – [7774-29-0].
Synonyms – Mercury diiodide, red mercury iodide.
Molecular formula and molar mass – HgI2 – 454.39.
Description – Scarlet red, crystalline, dense, odorless, and nearly insipid powder.
Physical characteristic – Melting temperature: 259 °C.
Solubility – Slightly soluble in water, moderately soluble in acetone and in ethyl alcohol, soluble in
excess potassium iodide solution.
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – Poison!
Potassium iodide
CAS – [7681-11-0].
Molecular formula and molar mass – KI – 166.00.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Description – Colorless crystals or white crystalline powder, odorless, with salty and bitter flavor.
Faintly deliquescent.
Physical characteristic – Melting temperature: 680 °C.
Solubility – Very soluble in water, freely soluble in glycerol, soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light and humidity.
Potassium iodide RS
Specification – Contains 16.5% (w/v) of potassium iodide in water.
Conservation – In opaque, tightly closed containers.
Storage – Protect from light.
Propidium iodide
CAS – [25535-16-4]
Formula and molecular mass – C27H34I2N4 – 668.39
Safety – Carcinogenic
Preparation – Weigh 0.1 mg of reagent and add 10 mL of bi-distilled. Mix well.
Sodium iodide
CAS – [7681-82-5].
Molecular formula and molar mass – NaI – 149.89.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – White crystalline powder or colorless, hygroscopic, odorless crystals.
Solubility – Very soluble in water and freely soluble in ethyl alcohol.
Conservation – In hermetic containers.
Tetrabutylammonium iodide
CAS – [311-28-4].
Synonym – Tetra-n-butylammonium iodide.
Molecular formula and molar mass – C16H36IN – 369.37.
Description – White or faintly colored crystalline powder or crystals.
Solubility – Slightly soluble in water and soluble in ethyl alcohol.
Indigo carmine
CAS – [860-22-0].
Molecular formula and molar mass – C16H8N2Na2O8S2 – 466,36.
Description – Blue granules with copper luster, or blue or violet-blue powder.
Solubility – Moderately soluble in water, practically soluble in ethyl alcohol. Precipitates in aqueous
sodium chloride solutions.
Indigo carmine RS
Preparation – In a mixture of 10 mL hydrochloric acid and 990 mL of 20% (w/v) sulfuric acid, add
0.2 g of indigo carmine.
Iodine
CAS – [7553-56-2].
Molecular formula and molar mass – I2 – 253.80.
Description – Blue-black or violet-gray scales, plates or small crystals; metallic luster, of irritant odor.
Physical characteristics – Slowly sublimates at room temperature; when heated, releases violet
vapors. Melting temperature: 113.6 °C
Solubility – Very slightly soluble in water, soluble in ethyl alcohol and slightly soluble in glycerol.
Conservation – In hermetic glass containers.
Safety – Corrosive vapors.
Iodine RS
Synonyms – Aqueous iodine solution – iodized, lugol reactive.
Specification – Contains 1 g of iodine and 2 g of potassium iodide in 100 mL of aqueous preparation.
Preparation – Dissolve 1 g of iodine in 100 mL of water, add 2 g of potassium iodide, shake, allow
to stand for a few hours, and filter through glass wool.
Conservation – In tightly closed amber glass containers.
Storage – Protect from light.
Iodine 0.05 M
Preparation – Dissolve 20 g of potassium iodide in the minimum amount of water, add 13 g of iodine,
then add water to complete the volume to 1000 mL.
Potassium iodobismuthate
Use aqueous-acetic potassium iodobismuthate.
Potassium iodobismuthate RS
Preparation – Dissolve 16.6 g of tartaric acid in 67 mL of water and add 1.41 g of bismuth subnitrate.
Shake for one hour, add 33 mL of 40% (w/v) aqueous potassium iodide solution. Shake for one more
hour. Allow to stand for 24 hours. Filter.
Conservation – In tightly closed containers.
Storage – Protect from light.
Iodosulfuron RS
Preparation – Use a round flask with 3 L to 4 L, with three tubes, one stirrer, one thermometer and
one drying tube. The flask must be dry and closed during the preparation. Mix 700 mL of pyridine
with 700 mL of methoxyethanol; add, stirring, 220 g of iodine, finely powdered and dried in advance,
under phosphorus pentoxide. The agitation must be maintained until complete dissolution
(approximately 30 minutes). Cool down at -10 °C and, stirring, quickly introduce 190 g of liquid
sulfur dioxide. The temperature must not exceed 30 °C. Cool down.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Assay – Determine the titer in the moment of use, always working protected from light. Introduce in
an Erlenmeyer flask approximately 20 mL of methyl alcohol and proceed to the Water determination
by the semi-micro method (5.2.20.3), with the sample, until the titration endpoint. Introduce in the
Erlenmeyer flask an accurately weighed amount of water and perform a new titration. Calculate the
equivalent in water of the sample, in mg/mL. Each mL of iodosulfuron RS is equivalent to no less
than 3.5 mg of water.
Conservation – In a dry container.
Irganox 1010
CAS – [6683-19-8].
Molecular formula and molar mass – C73H108O12 – 1177.66.
Description – White to slightly yellow powder. Odorless, insipid.
Physical characteristics – Melting range: 110 °C to 125 °C. Crystallizes in two forms: alpha form,
melting range 120 °C to 125 °C; and beta form, melting range 110 °C to 115 °C. The melting range
varies according to the proportion of crystalline forms in the mixture; this proportion does not
influence the product efficiency.
Category – Stabilizer for organic substances, such as polyethylene and polypropylene, protecting
them from thermo-oxidative degradation.
Irganox 1076
CAS – [2082-79-3].
Molecular formula and molar mass – C35H62O3 – 530.88.
Description – White to slightly yellow powder. Odorless, stable to light.
Physical characteristic – Melting range: 49 °C to 54 °C
Category – Antioxidant for organic substrates, such as polyethylene and polypropylene, protecting
them from thermo-oxidative degradation.
Irganox PS 800
CAS – [123-28-4].
Molecular formula and molar mass – C30H58O4S – 514.85.
Description – White crystals.
Physical characteristic – Melting range: 38 °C to 40 °C
Category – Stabilizer of polyolefins, especially high-density polyethylene and polypropylene.
Isooctane
CAS – [540-84-1].
Synonym – 2,2,4-Trimethylpentane.
Molecular formula and molar mass – C8H18 – 114.23.
Description – Colorless liquid.
Physical characteristics – Density (20 °C): 0.691 to 0.696. Refractive index (20 °C): 1.391 to 1.393.
Solubility – Practically insoluble in water and soluble in ethyl alcohol.
Conservation – In closed containers.
Safety – Flammable.
Fluorescein isothiocyanate
CAS – [27072-45-3].
Molecular formula and molar mass – C21H11NO5S – 389.38. Specification – Mixture of isomers: 5-
isothiocyanate and 6-isothiocyanate. Description – Orange solid, decomposes with heating.
Lactose
CAS – [5989-81-1].
Synonym – Lactose monohydrate.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Methyl laurate
CAS – [111-82-0].
Molecular formula and molar mass – C13H26O2 – 214.35.
Specification – Contains no less than 98.0% (w/v).
Description – Colorless or yellow liquid.
Physical characteristics – Density (20 °C): approximately 0.870. Refractive index (20 °C):
approximately 1.431. Melting temperature: approximately 5 °C.
Conservation – In tightly closed containers.
Lecithin
Specification – Mixture of diglycerides, especially of stearic, palmitic and oleic acids, bonded to the
phosphoric acid from choline. Variable structure and composition according to the source.
Description – Fatty yellow-brown mass, with faint characteristic odor.
Conservation – In tightly closed containers.
Labeling – Specify origin.
Nickel-aluminum alloy
Description – Gray fine powder.
Solubility – Practically insoluble in water, soluble in mineral acids with formation of salt.
Linalool
CAS – [78-70-6].
Molecular formula and molar mass – C10H18O – 154.25.
Description – Liquid. Mixture of two stereoisomers (licareol and coriandrol).
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Physical characteristics – Density (20 °C): approximately 0.860. Boiling temperature: approximately
200 °C. Refractive index (20 °C): approximately 1.462.
Solubility – Practically insoluble in water.
Lithium
CAS – [7439-93-2].
Element and atomic mass – Li – 6.94.
Solubility – Reacts violently with water. Soluble in methyl alcohol, forming lithium methoxide.
Practically insoluble in petroleum ether.
Macrogol 300
CAS – [25322-68-3].
Synonyms – PEG 300, polyethylene glycol 300.
Molecular formula and molar mass – H(OCH2CH2)nOH – Molar mass not inferior to 95.0% of the
nominal value labeled. Presents the average number of 6 or 7 oxyethylene groups (n = 6 or 7).
Specification – Mixture of products from the polycondensation of ethylene oxide and water.
Description – Colorless or nearly colorless, clear, viscous liquid, with faint and characteristic odor.
Hygroscopic.
Physical characteristics – Density: approximately 1.125. Refractive index (20 °C): approximately
1.465. Viscosity: approximately 80 cP.
Conservation – In hermetic containers.
Labeling – It must state the average molar mass. Storage – Protect from humidity.
Macrogol 1000
CAS – [25322-68-3].
Synonyms – PEG 1000, polyethylene glycol 1000.
Molecular formula and molar mass – H(OCH2CH2)nOH – Molar mass not inferior to 95.0% of the
nominal value labeled.
Description – White or nearly white solid with waxy appearance. Hygroscopic.
Physical characteristics – Density: approximately 1.080. Freezing range: between 35 °C and 40 °C.
Solubility – Very soluble in water, freely soluble in ethyl alcohol and in methylene chloride.
Practically insoluble in fatty oils and in mineral oils.
Conservation – In hermetic containers.
Labeling – It must state the average molar mass. Storage – Protect from humidity.
Magneson
CAS – [74-39-5].
Molecular formula and molar mass – C12H9N3O4 – 259.22.
Description – Red-brown powder.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Melamine
CAS – [108-78-1].
Molecular formula and molar mass – C3H6N6 – 126.12.
Description – White or nearly white amorphous powder.
Solubility – Very slightly soluble in water and in ethyl alcohol.
2- Mercaptoethanol
CAS – [60-24-2].
Molecular formula and molar mass – C2H6OS – 78.14.
Description – Clear and colorless liquid.
Physical characteristics – Density (20 °C): approximately 1.116. Boiling temperature: approximately
157 °C.
Miscibility – Miscible with water.
Mercaptopurine
CAS – [6112-76-1].
Molecular formula and molar mass – C5H4N4S.H2O – 170.20.
Description – Yellow crystalline powder.
Solubility – Practically insoluble in water and slightly soluble in ethyl alcohol. Soluble in alkali
hydroxide solutions.
Storage – Protect from light.
Mercury
CAS – [7439-97-6].
Element and atomic mass – Hg – 200.59.
Specification – Liquid, mobile, dense, silvery metal, of mirrored surface.
Physical characteristics – Density (°C): approximately 13.5. Boiling temperature: approximately 357
°C.
Conservation – In tightly closed containers.
Safety – Poison! Volatile at room temperature.
Sodium metabisulfite
CAS – [7681-57-4].
Synonyms – Sodium disulfite, sodium pyrosulfite.
Molecular formula and molar mass – Na2S2O5 – 190.10.
Specification – Contains no less than 95% (w/w). Contains an amount of sodium metabisulfite
equivalent to no less than 65.0% and no more than 67.4% of sulfur dioxide (SO2).
Description – Colorless crystals or white or cream-white crystalline powder, with sulfurous odor and
acid and saline flavor.
Solubility – Freely soluble in water and slightly soluble in ethyl alcohol.
Conservation – In tightly closed, full containers.
Storage – Protect from excessive heat, air and humidity.
Stability – Slowly oxidizes at sulfate, by exposure to air and to humidity, with disintegration of
crystals.
Methenamine
CAS – [100-97-0].
Synonym – Hexamethylenetetramine.
Molecular formula and molar mass – C6H12N4 – 140.19.
Specification – Contains no less than 99.0% (w/w), after desiccation on atmosphere of phosphorus
pentoxide for four hours.
Description – Colorless crystalline powder.
Physical characteristics – Sublimates without melting and with partial decomposition at
approximately 263 °C. The pH of the 0.2 M solution is 8.4.
Solubility – Very soluble in water. Conservation – In tightly closed containers. Therapeutic class –
Urinary antiseptic.
Methylcellulose 450
CAS – [9004-67-5].
Specification – Partially O-methylated cellulose with viscosity of 450 mPa/second. Description –
White, yellow-white or grey-white granule or powder. Hygroscopic. Solubility – Practically insoluble
in hot water, in acetone, absolute ethyl alcohol and toluene.
4,4-Methylenebis-N,N-dimethylaniline
CAS – [101-61-1].
Synonym – Tetramethyldiaminediphenylmethane.
Molecular formula and molar mass – C17H22N2 – 254.38.
Description – White or bluish-white crystals or leaflets.
Physical characteristic – Melting range: 90 °C to 91 °C.
Solubility – Practically insoluble in water, slightly soluble in ethyl alcohol and soluble in mineral
acids.
Conservation – In closed containers.
Methylenebisacrylamide
CAS – [110-26-9].
Synonyms – N,N’-methylenebisacrylamide, methylenebispropenamide.
Molecular formula and molar mass – C7H10N2O2 – 154.17.
Description – White or nearly white fine powder.
Physical characteristic – Melting temperature: above 300 °C, with decomposition.
Methyl-ethyl-ketone
CAS – [78-93-3].
Synonyms – Ethylmethylketone, 2-butanone.
Molecular formula and molar mass – C4H8O – 72.11.
Description – Clear and colorless liquid. Characteristic odor of acetone.
Physical characteristics – Density (20 °C): approximately 0.81. Boiling temperature: 79.6 °C.
Conservation – In hermetic containers.
Safety – Toxic. Flammable.
Methylisobutylketone
CAS – [108-10-1].
Synonym – 4-Methyl-2-pentanone, isopropylacetone.
Molecular formula and molar mass – C6H12O – 100.16.
Description – Colorless liquid, with ketonic and camphor odor.
Physical characteristics – Boiling temperature: approximately 115 °C
Methylparaben
CAS – [99-76-3].
Synonym – 4-hydroxybenzoic acid methyl ester.
Molecular formula and molar mass – C8H8O3 – 152.15.
Description – White crystals, slightly soluble in water, freely soluble in acetone, in ethyl alcohol and
in ethyl ether.
Solubility – Very slightly soluble in water and freely soluble in ethyl alcohol and in methyl alcohol.
Category – Preservative.
4-Methyl-2-pentanol
CAS – [108-11-2].
Molecular formula and molar mass – C6H14O – 102.18.
Description – Colorless, clear and volatile liquid.
Physical characteristics – Density (20 °C): approximately 0.802. Refractive index (20 °C):
approximately 1.411. Boiling temperature: approximately 132 °C.
3-Methyl-2-pentanone
CAS – [565-61-7].
Molecular formula and molar mass – C6H12O – 100.16.
Description – Colorless and flammable liquid.
Physical characteristics – Boiling temperature: approximately 118 °C. Density (20 °C):
approximately 0.815. Refractive index (20 °C): approximately 1.400.
Conservation – In closed containers.
Methoxyazobenzene
CAS – [2396-60-3].
Molecular formula and molar mass – C13H12N2O – 212.25.
Description – Orange blades.
Solubility – Practically insoluble in water, soluble in ethyl alcohol, in petroleum ether and in other
organic solvents.
Thin layer chromatography (5.2.17.1) – Apply, on a silica gel G plate, a solution with 5 mg of
methoxyazobenzene in benzene and develop a chromatogram with the same solvent. A single stain
appears, with Rf of approximately 0.6.
Methoxyazobenzene RS
Specification – Solution at 0.2% (w/v) in a mixture of one volume of benzene with four volumes of
petroleum ether.
Potassium methoxide
CAS – [865-33-8].
Molecular formula and molar mass – CH3OK – 70.13.
Stability – Extemporaneous preparation.
Sodium methoxide
CAS – [124-41-4].
Molecular formula and molar mass – CH3ONa – 54.02.
Description – White fine powder. Reacts violently with water with formation of heat. Sensitive to air.
May be presented in the form of: CH3ONa.2CH3OH, white powder. In solution, it can be prepared in
situ.
Solubility – Soluble in ethyl alcohol and in methyl alcohol.
Conservation – In hermetic containers.
Storage – Protect from humidity.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Methoxyethanol
CAS – [109-86-4].
Synonyms – 2-Methoxyethanol, ethylene glycol monomethyl ether.
Molecular formula and molar mass – C3H8O2 – 76.10.
Description – Colorless and clear liquid.
Physical characteristics – Density (20 °C): approximately 0.9663. Refractive index (20 °C):
approximately 1.4028. Boiling temperature: approximately 125 °C.
Miscibility – Miscible with water, acetone and ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Poisonous! Use in places with proper ventilation.
Methyl myristate
CAS – [124-10-7].
Molecular formula and molar mass – C15H30O2 – 242.40.
Specification – Contains no less than 98.0% (w/v).
Description – Colorless or faintly yellow liquid.
Physical characteristics – Density (20 °C): approximately 0.868. Refractive index (20 °C):
approximately 1.437. Melting temperature: approximately 20 °C.
Miscibility – Miscible with ethyl alcohol and petroleum ether.
Conservation – In tightly closed containers.
Reducer mixture
Preparation – Powder the substances, added on the following order, to obtain a homogeneous
mixture: 20 mg of potassium bromide, 0.5 g of hydrazine sulfate and 5 g of sodium chloride.
Sulfochromic mixture
Preparation – Dissolve 50 g of potassium dichromate in approximately 50 mL of water and add
1000 mL of sulfuric acid.
Conservation – In tightly closed containers.
Ammonium molybdate
CAS – [12054-85-2].
Molecular formula and molar mass – (NH4)6Mo7O24.4H2O – 1235.92.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless to slightly yellow or blue-green, brilliant crystals.
Solubility – Soluble in water and practically insoluble in ethyl alcohol.
Physical characteristics – Loses water and ammonia by heating.
Conservation – In tightly closed containers.
Ammonium molybdate RS
Specification – Contains 10 g of ammonium molybdate in 100 mL of aqueous solution.
Conservation – In tightly closed containers.
mixture of 32 mL of nitric acid with 40 mL of water. Allow to stand for 48 hours and filter in a
crucible with sintered bottom of fine porosity. This solution deteriorates under storage and is
inadequate for use if, after adding 2 mL of sodium phosphate dibasic dodecahydrate RS in 5 mL of
solution, an abundant yellow precipitate does not form immediately or after slight heating. If there is
formation of precipitate during the storage, employ only the clear supernatant solution.
Storage – Protect from light.
Sodium molybdate
CAS – [10102-40-6].
Molecular formula and molar mass – Na2MoO4.2H2O – 241.95.
Description – Colorless crystals or white or nearly white crystalline powder.
Solubility – Freely soluble in water.
Molybdovanadate RS
Synonyms – Molybdovanadate reagent, vanadate-molybdate reagent.
Preparation – Using finely powdered substances, prepare a suspension of 4 g ammonium molybdate
and 0.1 g of ammonium vanadate in 70 mL of water. Add 20 mL of nitric acid. Complete the volume
to 100 mL with water.
Conservation – In tightly closed containers.
Storage – Protect from light.
Morpholine
CAS – [110-91-8].
Synonyms – Tetrahydro-2H-1,4-oxazine, diethylene oximide.
Molecular formula and molar mass – C4H9NO – 87.12.
Description – Colorless liquid. Hygroscopic.
Physical characteristic – Boiling temperature: approximately 128 °C.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In hermetic containers.
Morin
CAS – [6472-38-4].
Molecular formula and molar mass – C15H10O7.2H2O – 338.27.
Naphthalene
CAS – [91-20-3].
Molecular formula and molar mass – C10H8 – 128.17.
Description – White or nearly white crystals.
Physical characteristics – Melting temperature: approximately 80 °C. Boiling range: between 217 °C
and 219 °C.
Solubility – Practically insoluble in water, soluble in ethyl alcohol and freely soluble in benzene and
chloroform.
Conservation – In tightly closed containers.
1,3-Naphthalenediol
CAS – [132-86-5].
Molecular formula and molar mass – C10H8O2 – 160.17.
Description – Crystalline, usually brown-violet powder.
Physical characteristic – Melting temperature: approximately 125 °C.
Solubility – Freely soluble in water and in ethyl alcohol.
2,7-Naphthalenediol
CAS – [582-17-2].
Molecular formula and molar mass – C10H8O2 – 160.17.
Description – Yellow to nearly white crystalline solid or powder.
Physical characteristics – Melting range: 187 °C to 191 °C.
Solubility – Soluble in water and in ethyl alcohol.
Naphthalenediol, reagent
Preparation – Dissolve 20 mg of 1,3-naphthalenediol in 10 mL of ethyl alcohol with 0.2 mL of
sulfuric acid.
1-Naphthylamine
CAS – [134-32-7].
Synonym – α-Naphthylamine.
Molecular formula and molar mass – C10H9N – 143.19.
Description – Colorless crystals or white crystalline powder. Becomes red by exposure to air and
light. Unpleasant odor.
Physical characteristic – Melting range: 49 °C to 51 °C.
Solubility – Slightly soluble in water and freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light and from air.
Safety – Harmful vapor and powder.
1-Naphthol
CAS – [90-15-3].
Synonyms – Alpha-naphthol, α-naphthol.
Molecular formula and molar mass – C10H8O – 144.17.
Description – Colorless, white or nearly white crystals, or white or nearly white crystalline powder.
Turns dark with exposure to light.
Physical characteristic – Melting temperature: approximately 95 °C.
Solubility – Slightly soluble in water and freely soluble in ethyl alcohol.
Conservation – In closed containers.
Storage – Protect from light.
1-Naphthol RS
Specification – Contains 20% (w/v) of 1-naphthol in ethyl alcohol.
Conservation – In tightly closed containers.
Stability – Prepare immediately before use. Storage – Protect from light.
1-Naphthol
CAS – [135-19-3].
Synonyms – Beta-naphthol, b-naphthol.
Molecular formula and molar mass – C10H8O – 144.17
Description – White to slightly pink crystalline powder, of faint phenolic odor.
Physical characteristic – Melting temperature: approximately 122 °C
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Solubility – Very slightly soluble in water and very soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light.
2-Naphthol RS
Synonyms – Beta-naphthol RS, b-naphthol RS.
Specification – Contains 1 g of 2-naphthol in 100 mL of 1% (w/v) sodium hydroxide.
Conservation – In tightly closed containers.
Stability – Prepare immediately before use.
Storage – Protect from light.
2-Naphthol RS1
Synonyms – Beta-naphthol RS1, b-naphthol RS1.
Preparation – Dissolve 5 g of freshly recrystallized 2-naphthol in 40 mL of sodium hydroxide 2
M and complete the volume to 100 mL with water.
Conservation – In tightly closed containers.
Stability – Prepare immediately before use.
Storage – Protect from light.
Naringin
CAS – [10236-47-2].
Molecular formula and molar mass – C27H32O14 – 580.54.
Description – White or nearly white crystalline powder.
Physical characteristic – Melting temperature: approximately 171 °C.
Solubility – Slightly soluble in water, soluble in methyl alcohol and in dimethylformamide.
Ninhydrin
CAS – [485-47-2].
Synonym – Indantrione hydrate.
Molecular formula and molar mass – C9H4O3.H2O – 178.14
Specification – Contains no less than 96.0% (w/w).
Description – White to faintly pale yellow crystalline powder.
Solubility – Soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light.
Ninhydrin RS
Synonym – Indantrione hydrate RS.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Specification – Contains 0.2% (w/v) in a mixture of butyl alcohol and 2 M acetic acid (95:5).
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – Flammable.
Ammonium nitrate
CAS – [6484-52-2].
Molecular formula and molar mass – NH4NO3 – 80.04.
Description – Colorless, deliquescent crystals or white powder, with salty flavor.
Physical characteristics – Melting temperature: approximately 155 °C, decomposes around 210 °C
in water and nitrogen oxides.
Solubility – Very soluble in water, freely soluble in methyl alcohol and soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Ammonium nitrate RS
Specification – Contains 5 g of ammonium nitrate in 100 mL of aqueous solution.
Barium nitrate
CAS – [10022-31-8].
Molecular formula and molar mass – BaN2O6 – 261.34.
Description – Crystals or crystalline powder.
Physical characteristic – Melting temperature: approximately 590 °C.
Solubility – Freely soluble in water, very slightly soluble in ethyl alcohol and in acetone.
Conservation – In tightly closed containers. Safety – Poison!
Cadmium nitrate
CAS – [10022-68-1].
Molecular formula and molar mass – Cd(NO3)2.4H2O – 308.48.
Description – Colorless crystals. Hygroscopic.
Solubility – Very soluble in water and soluble in acetone and in ethyl alcohol.
Lead nitrate
CAS – [10099-74-8].
Synonym – Lead(II) nitrate.
Molecular formula and molar mass – Pb(NO3)2 – 331.21.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Cobalt(II) nitrate
CAS – [10026-22-9].
Synonym – Cobaltous nitrate.
Molecular formula and molar mass – CoN2O6.6H2O – 291.03.
Specification – Contains no less than 99.0% (w/w).
Description – Small, red, hygroscopic crystals.
Physical characteristic – Melting temperature: approximately 55 °C.
Solubility – Soluble in water.
Conservation – In tightly closed containers.
Storage – Protect from heat.
Cobalt(II) nitrate RS
Description – Contains 1.0% (w/v) cobalt(II) nitrate in methyl alcohol.
Conservation – In tightly closed containers.
Safety – Flammable. Toxic.
Lanthanum nitrate
CAS – [10277-43-7].
Molecular formula and molar mass – LaN3O9.6H2O – 433.01.
Description – Colorless, deliquescent crystals.
Solubility – Freely soluble in water.
Conservation – In tightly closed containers.
Lanthanum nitrate RS
Specification – Contains 5% (w/v) of lanthanum nitrate in water.
Conservation – In tightly closed containers.
Magnesium nitrate
CAS – [13446-18-9].
Molecular formula and molar mass – Mg(NO3)2.6H2O – 256.40.
Description – Colorless and deliquescent crystals.
Solubility – Very soluble in water and freely soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Mercury(I) nitrate
CAS – [14836-60-3].
Synonym – Mercurous nitrate.
Molecular formula and molar mass – Hg2N2O6.2H2O – 561.22.
Description – Colorless crystals, usually with faint odor of nitric acid.
Physical characteristic – Melting temperature: approximately 70 °C, with decomposition.
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – Poison!
Mercury(I) nitrate RS
Synonym – Mercurous nitrate RS.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Mercury(II) nitrate
CAS – [7783-34-8].
Synonym – Mercuric nitrate.
Molecular formula and molar mass – HgN2O6.H2O – 342.61.
Description – Colorless or faintly colored crystals. Hygroscopic.
Solubility – Soluble in water in presence of a small amount of nitric acid.
Conservation – In hermetic containers.
Storage – Protect from light and humidity. Safety – Poison!
Potassium nitrate
CAS – [7757-79-1].
Molecular formula and molar mass – KNO3 – 101.10.
Specification – Contains no less than 99.5% (w/w).
Description – Colorless and clear crystals or white, crystalline or granular powder.
Solubility – Very soluble in water.
Conservation – In tightly closed containers.
Silver nitrate
CAS – [7761-88-8].
Molecular formula and molar mass – AgNO3 – 169.87.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless clear crystals, or white crystalline powder. Odorless.
Physical characteristic – Melting temperature: 212 °C.
Solubility – Very soluble in water and soluble in ethyl alcohol.
Conservation – In closed non-metallic containers.
Storage – Protect from light.
Safety – Caustic. Poison!
Silver nitrate RS
Specification – Contains 4.25% (w/v) of silver nitrate in water.
Conservation – In tightly closed containers.
Storage – Protect from light.
Sodium nitrate
CAS – [7631-99-4].
Molecular formula and molar mass – NaNO3 – 84.99.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Description – Colorless and clear crystals, or white or nearly white granule or powder. Deliquescent.
Physical characteristic – Melting temperature: 308 °C.
Solubility – Freely soluble in water and slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Sodium nitrate RS
Specification – Contains 10 g of sodium nitrate in 100 mL of aqueous solution.
Stability – Prepare immediately before use.
Thorium nitrate
CAS – [13470-07-0].
Molecular formula and molar mass – ThN4O12.4H2O – 552.12.
Description – White crystals or crystalline, slightly deliquescent powder.
Solubility – Very soluble in water and ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Zirconyl nitrate
CAS – [14985-18-3].
Synonym – Zirconium nitrate.
Molecular formula – ZrO(NO3)2.xH2O.
Description – White or nearly white powder or crystals.
Conservation – In tightly closed containers.
Zirconyl nitrate RS
Preparation – Dissolve 0.1 g of zirconyl nitrate in a mixture of 60 mL of hydrochloric acid with
40 mL of water.
Conservation – In tightly closed containers.
Phenylmercuric nitrate
CAS – [55-68-5].
Synonyms – Basic phenylmercury nitrate and phenylmercury nitrate.
Molecular formula and molar mass – C6H5HgNO3 – 339.70.
Specification – Consists of a mixture of nitrate and phenylmercury ion hydroxide (C6H5Hg+).
Contains no less than 87.9% (w/w) phenylmercuric ion and no less than 62.75% (w/w) mercury (Hg)
.
Description – White crystalline powder or white lustrous scales. Odorless.
Physical characteristic – Melting range: between 175 °C and 190 °C, with decomposition.
Solubility – Very soluble in water and in ethyl alcohol, slightly soluble in hot water. Soluble in
glycerol and fatty oils.
Conservation – In hermetic containers.
Storage – Protect from light.
Nitrazepam
CAS – [146-22-5].
Molecular formula and molar mass – C15H11N3O3 – 281.27.
Description – Yellow crystalline powder.
Physical characteristic – Melting range: 226 °C to 230 °C.
Solubility – Practically insoluble in water and slightly soluble in ethyl alcohol.
Conservation – In closed containers.
Storage – Protect from exposure to light.
Sodium nitrite
CAS – [7632-00-0].
Molecular formula and molar mass – NaNO2 – 69.00.
Specification – Contains no less than 97.0% (w/w).
Description – White or slightly yellow granulated powder or colorless crystals. Hygroscopic.
Physical characteristics – Melting temperature: 271 °C. Decomposes above 320 °C.
Solubility – Freely soluble in water.
Conservation – In tightly closed containers.
Stability – Oxidizes on air very slowly, forming nitrate.
Sodium nitrite RS
Specification – Contains 10 g of sodium nitrite in 100 mL of aqueous solution.
Conservation – Prepare immediately before use.
p-Nitroaniline
CAS – [100-01-6].
Molecular formula and molar mass – C6H6N2O2 – 138.13.
Description – Light crystalline powder.
Physical characteristic – Melting range: from 146 °C to 148 °C.
Solubility – Insoluble in water and soluble in ethyl alcohol and ethyl ether. It forms a salt soluble in
aqueous solution with strong mineral acid.
Conservation – In tightly closed containers.
2-Nitrobenzaldehyde
CAS – [552-89-6].
Molecular formula and molar mass – C7H5NO3 – 151.12.
Description – Yellow crystals, with odor similar to almond oil.
Physical characteristic – Melting temperature: approximately 42 °C.
Solubility – Slightly soluble in water and freely soluble in ethyl alcohol.
Nitrobenzene
CAS – [98-95-3].
Synonym – Nitrobenzol.
Molecular formula and molar mass – C6H5NO2 – 123.11.
Description – Colorless to pale yellow liquid, with odor similar to almond oil.
Physical characteristics – Boiling temperature: approximately 211 °C. Density: approximately 1.20.
Solubility – Practically insoluble in water; miscible with ethyl alcohol.
Conservation – In tightly closed containers.
Safety – Poison!
Nitromethane
CAS – [75-52-5].
Molecular formula and molar mass – CH3NO2 – 61.04.
Description – Colorless oily liquid, with characteristic odor.
Physical characteristic – Boiling temperature: approximately 102 °C.
Solubility – Slightly soluble in water; miscible with ethyl alcohol.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Sodium nitroprusside
CAS – [13755-38-9].
Synonyms – Disodium pentacyanonitrosylferrate(III) dihydrate, nitroprusside sodium, sodium
nitroferrocyanide.
Molecular formula and molar mass – Na2[Fe(CN)5(NO)].2H2O – 297.95.
Description – Dark red, clear powder or crystals.
Solubility – Freely soluble in water and slightly soluble in ethyl alcohol.
Sodium 1-octanesulfonate
CAS – [5324-84-5].
Molecular formula and molar mass – C8H17NaO3S – 216.27.
Specification – Contains no less than 98.0% of C8H17NaO3S.
Description – White or nearly white flakes or crystalline powders.
Octoxynol 10
CAS – [9002-93-1].
Molecular formula and molar mass – (C2H4O)10C14H22O – 646.86.
Description – Light yellow clear, viscous liquid.
Solubility – Miscible with water, acetone and ethyl alcohol; soluble in toluene.
Conservation – In tightly closed container.
Olive oil
CAS – [8001-25-0].
Specification – Fixed oil obtained from the ripe fruit of Olea europaea L. – Oleaceae.
Descripton – Pale yellow or green-yellow oil.
Physical characteristic – Density: 0.910 to 0.915.
Solubility – Practically insoluble in ethyl alcohol; miscible with chloroform, ethyl ether and
petroleum ether.
Ammonium oxalate
CAS – [6009-70-7].
Molecular formula and molar mass – C2H8N2O4.H2O – 142.11.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless clear crystals or white crystalline powder. Odorless.
Physical characteristic – Melting temperature: 212 °C.
Solubility – Soluble in water. Conservation – In tightly closed containers.
Safety – Caustic. Corrosive. Poison!
Ammonium oxalate RS
Use ammonium oxalate TS.
Potassium oxalate
CAS – [6487-48-5].
Molecular formula and molar mass – K2C2O4.H2O – 184.23; if anhydrous – 166.21.
Description – Colorless, odorless crystals, efflorescent to hot and dry air.
Physical characteristic – Loses water at approximately 160 °C
Conservation – In hermetic containers.
Storage – Protect from humidity.
Safety – Poison!
Sodium oxalate
CAS – [62-76-0].
Molecular formula and molar mass – Na2C2O4 – 134.00.
Description – White or nearly white crystalline powder.
Solubility – Soluble in water and practically insoluble in ethyl alcohol.
Aluminum oxide
CAS – [1344-28-1].
Synonym – Alumina.
Molecular formula and molar mass – Al2O3 – 101.96.
Description – White fine granulated powder.
Physical characteristic – The pH (5.2.19) of the suspension at 10.0% (w/v) is between 9.0 and 10.0.
Conservation – In hermetic containers.
Holmium oxide
CAS – [12055-62-8].
Molecular formula and molar mass – Ho2O3 – 377.86.
Specification – Contains no less than 99.9% (w/w).
Description – Yellow powder.
Solubility – Practically insoluble in water.
Conservation – In tightly closed containers.
Magnesium oxide
CAS – [1309-48-4].
Synonym – Light or heavy magnesium oxide.
Molecular formula and molar mass – MgO – 40.30.
Specification – Contains no less than 95.0% (w/w).
Description – White, odorless, fine amorphous powder, with faint alkaline flavor.
Conservation – In tightly closed containers.
Storage – Protect from contact with air and with humidity.
Silver oxide
CAS – [20667-12-3].
Molecular formula and molar mass – Ag2O – 231.74.
Description – Dark gray powder.
Solubility – Practically insoluble in water and in ethyl alcohol, freely soluble in diluted nitric acid and
in ammonium hydroxide.
Conservation – In closed containers.
Storage – Protect from light.
Mercuric oxide
CAS – [21908-53-2].
Synonyms – Yellow mercury oxide, mercury(II) oxide.
Molecular formula and molar mass – HgO – 216.59.
Specification – Contains no less than 99.5% (w/w).
Description – Dense, odorless orange-yellow powder.
Solubility – Practically insoluble in water and in ethyl alcohol.
Storage – Protect from light.
Safety – Poison!
Methyl palmitate
CAS – [112-39-0].
Molecular formula and molar mass – C17H34O2 – 270.46.
Description – White or yellow crystalline mass.
Physical characteristics – Density (30 °C): approximately 0.86. Melting temperature: approximately
30 °C.
Solubility – Soluble in ethyl alcohol and in petroleum ether.
Conservation – In tightly closed containers.
Liquid paraffin
Specification – Purified mixture of liquid saturated hydrocarbons obtained from petroleum.
Description – Colorless and clear oily liquid.
Physical characteristics – Density: 0.827 to 0.890. Viscosity: 110 mPa to 230 mPa.
Solubility – Practically insoluble in water and slightly soluble in ethyl alcohol; miscible with hydrocarbons.
Conservation – In tightly closed containers.
Storage – Protect from light.
Phosphorus pentoxide
CAS – [1314-56-3].
Synonym – Phosphoric anhydride.
Molecular formula and molar mass – P2O5 – 141.94.
Description – White, amorphous, very deliquescent powder.
Physical characteristics – Melting temperature: 340 °C. Sublimation temperature: 360 °C.
Conservation – In hermetic containers.
Storage – Protect from humidity.
Safety – Irritant. Corrosive to skin, mucous membrane and eyes.
Vanadium pentoxide
CAS – [1314-62-1].
Molecular formula and molar mass – V2O5 – 181.88.
Specification – Contains no less than 99.5% (w/w).
Description – Yellow to orange-yellow fine powder.
Physical characteristic – Melting temperature: 690 °C.
Solubility – Slightly soluble in water and soluble in strong mineral acids and alkali hydroxide
solutions with formation of salts.
Conservation – In tightly closed containers.
Purified pepsin
Specification – Derived from porcine gastric mucosa, with activity of 800 to 2500 units/mg of protein.
Description – White or yellow, amorphous or crystalline powder. Hygroscopic.
Solubility – Soluble in water, practically insoluble in ethyl alcohol. The solution in water may turn
slightly opalescent with a small amount of acid.
Conservation – In closed container.
Storage – Protected from light and at temperature between 2 °C and 8 °C.
Labeling – It must express the pepsin activity.
Peptone
Specification – Mixture of products of polypeptide nature coming from animal proteins (meat,
casein). The origin determines the physical characteristics, composition and production process.
Description – Light yellow to brown powder. Characteristic odor and flavors. Minimum content in
nitrogen: 12.0% (w/w) of casein and 14.2% (w/w) of meat.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Labeling – It must express the origin and content in nitrogen.
Sodium perchlorate
CAS – [7791-07-3].
Synonym – Perchloric acid monohydrate sodium salt.
Molecular formula and molar mass – NaClO4.H2O – 140.45.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless, deliquescent crystals.
Solubility – Very soluble in water, soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Potassium periodate
CAS – [7790-21-8].
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Sodium periodate
CAS – [7790-28-5].
Synonym – Sodium metaperiodate.
Molecular formula and molar mass – NaIO4 – 213.89.
Specification – Contains no less than 99.0% (w/w) of sodium periodate.
Description – White tetragonal crystals.
Physical characteristic – Melting temperature: approximately 300 °C, with decomposition.
Solubility – Soluble in water, acetic acid, nitric acid and sulfuric acid.
Conservation – In tightly closed containers.
Storage – In ventilated places.
Safety – Strong oxidizing agent.
Potassium permanganate
CAS – [7722-64-7].
Molecular formula and molar mass – KMnO4 – 158.03.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Dark violet crystals, with metallic luster, odorless, of sweet astringent flavor.
Solubility – Soluble in cold water and freely soluble in water in ebullition.
Conservation – In tightly closed containers.
Storage – Protect from light.
Safety – The substance and its solutions present risk of explosion when in contact with oxidizable
materials.
Category – Energetic oxidizing agent.
Carbamide peroxide
CAS – [124-43-6].
Synonym – Urea hydrogen peroxide.
Molecular formula and molar mass – CH6N2O3 – 94.07.
Description – White crystals or crystalline powder. Decomposes at contact with air in urea, oxygen
and water.
Solubility – Soluble in water.
Conservation – In tightly closed containers. Category – Oxidizing agent.
CAS – [7722-84-1].
Synonym – Perhydrol.
Molecular formula and molar mass – H2O2 – 34.01.
Specification – Contains no less than 29.0% (w/w) of hydrogen peroxide. Corresponds to,
approximately, 100 parts in volume. May contain stabilizer.
Description – Clear, irritant liquid, with faint odor.
Physical characteristic – Density: 1.11.
Conservation – In partially full containers that have a relief closing system.
Storage – Protect from light and from heat.
Safety – Strong oxidizing agent.
Sodium peroxide
CAS – [1313-60-6].
Molecular formula and molar mass – Na2O2 – 77.98.
Description – Yellow-white granular powder.
Solubility – Freely soluble in water, forming sodium hydroxide and hydrogen peroxide, which
decomposes into oxygen gas and water.
Conservation – In tightly closed containers, protected from organic and oxidizable substances.
Ammonium persulfate
CAS – [7727-54-0].
Synonym –Ammonium peroxydisulfate.
Molecular formula and molar mass – H8N2O8S2 – 228.19.
Specification – Contains no less than 95.0% (w/w).
Description – White crystals or granulated powder. Odorless. Stable for months when pure and dry;
decomposes in presence of humidity.
Solubility – Freely soluble in water.
Conservation – In hermetic containers.
Storage – Protect from humidity, heat and organic material.
Additional information – Strongly oxidizing agent.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Potassium persulfate
CAS – [7727-21-1].
Molecular formula and molar mass – K2S2O8 – 270.32.
Description – Colorless crystals or white or nearly white crystalline powder.
Solubility – Moderately soluble in water, practically insoluble in ethyl alcohol. In aqueous solution,
decomposes at room temperature, and the increase in temperature leads to higher decomposition
speed.
Conservation – In tightly closed containers.
Storage – In a ventilated place.
Sodium persulfate
CAS – [7775-27-1].
Molecular formula and molar mass – Na2O8S2 – 238.09.
Description – White crystalline powder. Slowly decomposes with humidity and by heat.
Conservation – In hermetic containers.
Storage – Protect from humidity and heat. Safety – Irritant.
Piperazine
CAS – [110-85-0].
Molecular formula and molar mass – C4H10N2 – 86.14.
Description – White or nearly white lumps or flakes. Ammoniacal odor.
Solubility – Soluble in water and in ethyl alcohol, insoluble in ethyl ether.
Pyridine
CAS – [110-86-1].
Molecular formula and molar mass – C5H5N – 79.10.
Description – Colorless liquid, with characteristic and unpleasant odor.
Physical characteristics – Boiling range: 115 °C to 116 °C.
Density (25 °C): approximately 0.980. Refractive index (20 °C): 1.5092.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Safety – Flammable. Toxic.
Pyridine anhydrous
Specification – Contains no more than 0.01% (w/w) water.
Preparation – Dry the pyridine with anhydrous sodium carbonate. Filter and distill.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Safety – Flammable. Toxic.
Potassium pyroantimonate RS
Preparation – Dissolve 2 g of potassium pyroantimonate in 85 mL of hot water. Cool it down quickly
and add 50 mL of the potassium hydroxide solution 5% (w/v) potassium hydroxide solution and 1
mL of the 8.5% (w/v) sodium hydroxide solution. Allow to stand for 24 hours, filter and dilute with
water to 150 mL.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Sodium pyrophosphate
CAS – [13472-36-1].
Molecular formula and molar mass – Na4P2O7.10H2O – 446.05.
Description – Colorless, slightly efflorescent crystals.
Physical characteristic – Melting temperature: 79.5 °C.
Solubility – Freely soluble in water.
Conservation – In tightly closed containers.
Pyrogallol
CAS – [87-66-1].
Molecular formula and molar mass – C6H6O3 – 126.11.
Description – White or nearly white crystals. Becomes brown by exposure to air and light.
Physical characteristic – Melting temperature: approximately 131 °C.
Solubility – Very soluble in water and in ethyl alcohol. Aqueous solutions become brown by exposure
to air.
Conservation – In closed containers.
Storage – Protect from light.
Polyacrylamide
CAS – [9003-05-8].
Synonym – Acrylamide polymer.
Molecular formula and molar mass – (C3H5NO)n; monomer – 71.08.
Specification – Polymer in several forms, soluble and insoluble in water, obtained by heating with
several polymerization catalysts.
Conservation – In tightly closed containers.
Safety – Highly toxic and irritant. Causes paralysis of the central nervous system. It may be absorbed
by intact skin.
Polysucrose
CAS – [26873-85-8]
Molecular formula – (C12H22O11.C3H5ClO)n
Description – White or nearly white powder.
Polysorbate 20
Refer to the Polysorbate 20 monograph.
Polysorbate 80
Specification – Mixture of sorbitol oleates and their copolymerized anhydrides with, approximately,
20 M ethylene oxide for every mol of sorbitol and anhydride.
Description – Yellow or dark yellow clear liquid. Oily. Faint characteristic odor.
Physical characteristics – Density: approximately 1.08. Viscosity: approximately 400 cP.
Conservation – In tightly closed containers.
Category – Surfactant.
Prednisolone
CAS – [50-24-8].
Molecular formula and molar mass – C21H28O5 – 360.45.
Specification – Contains no less than 97.0% (w/w) in relation to the desiccated substance.
Description – White or nearly white crystalline powder. Hygroscopic. Presented in anhydrous form
or containing one or half a molecule of hydration water.
Physical characteristic – Melting temperature: 240 °C to 241 °C, with decomposition.
Solubility – Very slightly soluble in water, soluble in ethyl alcohol and in methyl alcohol, moderately
soluble in acetone, and slightly soluble in methylene chloride.
Conservation – In tightly closed containers.
Therapeutic class – Corticoid.
Prednisone
CAS – [53-03-2].
Molecular formula and molar mass – C21H26O5 – 358.43.
Specification – Contains no less than 97.0% (w/w) in relation to the desiccated substance.
Description – White or nearly white crystalline powder.
Physical characteristic – Melting temperature: approximately 233 °C, with decomposition.
Solubility – Practically insoluble in water and slightly soluble in ethyl alcohol and in methylene
chloride.
Conservation – In tightly closed containers.
Therapeutic class – Corticoid.
Brilliant black BN
CAS – [2519-30-4].
Molecular formula and molar mass – C28H17N5Na4O14S4 – 867.69.
Description – Fine crystals, violet blue or grey-black powder. Redox indicator. Oxidized form: violet
blue. Reduced form: brown-yellow.
Physical characteristic – Specific absorptivity A (1%, 1 cm) is higher than 0.390 at 570 nm.
Conservation – In tightly closed containers.
Propylene glycol
CAS – [57-55-6].
Synonym – 1,2-Propanediol.
Molecular formula and molar mass – C3H8O2– 76.10.
Description – Colorless, viscous, hygroscopic liquid.
Physical characteristics – Density (25 °C): 1.035 to 1.037. Boiling range: 187 °C to 189 °C.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Propylparaben
CAS – [94-13-3].
Synonym – 4-hydroxybenzoic acid propyl ester.
Molecular formula and molar mass – C10H12O3 – 180.20.
Description – White crystals.
Solubility – Very slightly soluble in water, freely soluble in ethyl alcohol and in ethyl ether.
Category – Preservative.
Phthalein purple
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
CAS – [2411-89-4].
Synonym – Metal phthalein.
Molecular formula and molar mass – C32H32N2O12 – 636.61.
Description – Light yellow to brown powder. It may be found in the form of sodium salt: light yellow
to pink powder.
Solubility – Practically insoluble in water and soluble in ethyl alcohol. In the form of sodium salt, it
is soluble in water and practically insoluble in ethyl alcohol.
Sensitivity assay – Dissolve 10 mg of phthalein purple in 1 mL of concentrated ammonia solution and
dilute to 100 mL with water. Add to 5 mL of the solution 95 mL of water, 4 mL of concentrated
ammonia solution, 50 mL of ethyl alcohol and 0.1 mL 0.1 M barium chloride VS. The solution
presents a violet blue color. Add 0.15 mL of 0.1 M disodium edetate VS. The solution must become
colorless.
Quinidine
CAS – [56-54-2].
Molecular formula and molar mass – C20H24N2O2 – 324.42.
Description – White or nearly white crystals.
Physical characteristics – Specific rotation power (20 °C): approximately +260°, determined on a
1% (w/v) quinidine solution in ethyl alcohol. Melting temperature: approximately 172 °C.
Solubility – Very slightly soluble in water, moderately soluble in ethyl alcohol and slightly soluble in
methyl alcohol.
Conservation – In closed containers.
Storage – Protect from exposure to light
Quinhydrone
CAS – [106-34-3].
Molecular formula and molar mass – C12H10O4 – 218.21.
Description – Lustrous crystals or dark green crystalline powder.
Physical characteristic – Melting temperature: 170 °C, may sublimate and decompose partially.
Solubility –Moderately soluble in cold water, soluble in hot water, ammonia and ethyl ether.
Conservation – In closed containers.
Quinine
CAS – [130-95-0].
Molecular formula and molar mass – C20H24N2O2 – 324.42.
Description – White or nearly white micro-crystalline powder.
Physical characteristics – Specific rotation power (20 °C): approximately -167°, determined on a 1%
(w/v) quinine solution in ethyl alcohol. Melting temperature: approximately 175 °C. Solubility – Very
slightly soluble in water, slightly soluble in water in ebullition and very soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light.
Rhaponticin
CAS – [155-58-8].
Molecular formula and molar mass – C21H24O9 – 420.41.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Aluminon reagent
Solution A – Dissolve 250 g of ammonium acetate in 500 mL of purified water. Add 40 mL of glacial
acetic acid; 0.5 g of aluminon dissolved in 50 mL of purified water; 1 g of benzoic acid dissolved in
150 mL of isopropyl alcohol; and 225 mL of isopropyl alcohol. Complete the volume to 1000 mL
with purified water.
Solution B – Dissolve 5 g of gelatin in 125 mL of hot purified water and mix with 250 mL of cold
purified water. Filter and complete the volume to 500 mL with purified water.
Preparation – Mix by stirring the Solutions A and B. The mixture must be completely clear when
cold. Store in a polyethylene container, protected from light.
Coloring reagent
Preparation – Mix 50 mL of glacial acetic acid and 50 mL of sulfuric acid. Allow to stand for two
hours before use. Store in a refrigerator for no more than 24 hours.
Folin-Denis reagent
Preparation – Add to 75 mL of water 10 g of sodium tungstate, 2 g of phosphomolybdic acid and
5 mL of phosphoric acid. Keep the mixture in reflux for two hours, cool down and complete the
volume to 100 mL with water. The solution presents a green color.
Hantzsch reagent
Preparation – Dissolve 150 g of ammonium acetate in 500 mL of distilled water with 3 mL of acetic
acid and 2 mL of acetylacetone. Complete the volume to 1000 mL.
Conservation – In a closed amber glass container.
Jones reagent
Preparation – Add to 40 mL of water 5.3 g of chromium trioxide and 24 mL of a mixture of water
and sulfuric acid (1:1).
Marquis reagent
Preparation – Mix 4 mL of formaldehyde solution with 100 mL of sulfuric acid.
Xanthydrol reagent
Preparation – Dissolve 0.125 g of xanthydrol in 100 mL of glacial acetic acid. Add 1 mL of
hydrochloric acid before use.
Phosphomolybdotungstic reagent
Preparation – Dissolve 100 g of sodium tungstate and 25 g of sodium molybdate in 700 mL of water.
Add 100 mL of hydrochloric acid and 50 mL of phosphoric acid. Heat the mixture under reflux in
glass apparatuses, for 10 hours. Add 150 g of lithium sulfate, 50 mL of water and a few drops of
bromine. Boil to remove the excess bromine (for approximately 15 minutes), let it cool down and
dilute to 1000 mL with water. Filter. The reagent presents a yellow color. If the solution presents a
green color, it must not be used, and must be regenerated with the addition of a few drops of bromine
to the reagent in ebullition. Then, boil the reagent to eliminate the excess bromine.
Storage – Keep at temperature between 2 °C and 8 °C.
Iodoplatinate reagent
Preparation – Mix equal volumes of 0.3% (w/v) chloroplatinic acid and 6% (w/v) potassium iodide.
Methoxyphenylacetic reagent
Preparation – Dissolve 2.7 g of methoxyphenylacetic acid in 6 mL of tetramethylammonium
hydroxide solution and add 20 mL of absolute ethyl alcohol.
Storage – In a polyethylene container.
Sulfomolybdic reagent
Preparation – Dissolve, by heating, 2.5 g of ammonium molybdate in 20 mL of water. Dilute 28 mL
of sulfuric acid in 50 mL of water and cool down. Mix the two solutions and complete the volume to
100 mL with water.
Ammonium reineckate
CAS – [13573-16-5].
Synonym – Ammonium tetrathiocyanatodiamminechromate.
Molecular formula and molar mass – C4H10CrN7S4.H2O – 354.45.
Description – Dark red crystals or crystalline red powder.
Solubility – Moderately soluble in chilled water, soluble in hot water and ethyl alcohol. Slowly
decomposes in solution.
Ammonium reineckate RS
Preparation – Constantly shake approximately 0.5 g of ammonium reineckate in 20 mL of water for
one hour and filter.
Stability – Use within two days.
Resazurin
CAS – [550-82-3].
Synonym – Diazoresorcinal.
Molecular formula and molar mass – C12H7NO4 – 229.19.
Description – Crystals or dark red crystalline powder.
Conservation – In tightly closed containers.
Resorcinol
CAS – [108-46-3].
Synonym – Resorcine.
Molecular formula and molar mass – C6H6O2 – 110.11.
Specification – Contains no less than 99.0% (w/w).
Description – Crystals, or colorless or pale yellow crystalline powder. When exposed to light and air,
acquires a pink color.
Physical characteristic – Melting range: 109 °C to 111 °C.
Solubility – Soluble in water and ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light and from air.
Ristocetin
CAS – [1404-55-3].
Synonym – Ristocetin A.
Molecular formula and molar mass – C94H108N8O44 – 2053.91.
Description – White solid. Also found as ristocetin sulfate.
Rhodamine B
CAS – [81-88-9].
Synonyms – Tetraethylrhodamine, Basic violet 10.
Molecular formula and molar mass – C28H31ClN2O3 – 479.02.
Description – Green crystals or red powder.
Solubility – Very soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from exposure to light and from heat.
Safety – Irritant.
Rutin
CAS – [153-18-4].
Molecular formula and molar mass – C27H30O16 – 610.52.
Description – Pale yellow needle-shaped crystals. Turns dark at presence of light.
Physical characteristic – Melting temperature: approximately 210 °C, with decomposition.
Solubility – Very slightly soluble in water and soluble in pyridine.
Conservation – In closed containers.
Storage – Protect from exposure to light.
Sucrose
CAS – [57-50-1].
Molecular formula and molar mass – C12H22O11 – 342.30.
Specification – It is obtained from Saccharum officinarum Linné (Gramineae family), Beta vulgares
Linné (Chenopodiaceae family) and other sources.
Description – White or colorless crystals; crystalline powder or crystalline mass or white blocks.
Odorless. Sweet flavor. Stable on air. Finely divided, it is hygroscopic and absorbs up to 1% of
humidity. Contains no additives.
Physical characteristic – Decomposition: between 160 °C and 186 °C.
Solubility – Very soluble in water, slightly soluble in ethyl alcohol and practically insoluble in
absolute ethyl alcohol.
Conservation – In tightly closed containers.
Safranine O
CAS – [477-73-6].
Description – Dark red powder. It consists of a mixture of 3,7-diamino-2,8-dimethyl-5-
phenylphenazinium (C20H19ClN4 – 350.85) chloride and 3,7-diamino-2,8-dimethyl-5,o-
tolylphenazinium (C21H21ClN4 – 364.88) chloride. Redox indicator. Oxidized form: acid medium,
violet blue color; alkaline medium, brown color. Reduced form: colorless both in acidic and in
alkaline medium.
Physical characteristic – In the ultraviolet absorption spectrum (5.2.14), there is a maximum between
530 nm and 533 nm.
Conservation – In tightly closed containers.
Sodium salicylate
CAS – [54-21-7].
Molecular formula and molar mass – C7H5NaO3 – 160.10.
Description – Small colorless crystals; or white crystalline powder; or bright flakes.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Santonin
CAS – [481-06-1].
Molecular formula and molar mass – C15H18O3 – 246.31.
Description – Colorless crystals. If exposed to light, may acquire a yellow color.
Physical characteristic – Melting range: 174 °C to 176 °C.
Solubility – Very slightly soluble in water, freely soluble in hot ethyl alcohol and moderately soluble
in ethyl alcohol.
Saponins
CAS – [8047-15-2].
Description – Light yellow powder.
Solubility – Soluble in water and, under agitation, forms foam.
Conservation – In closed containers.
Silica, desiccated
CAS – [7631-86-9].
Molecular formula and molar mass – SiO2 – 60.08.
Specification – Colloidal, polymerized, previously dehydrated silicic acid; contains cobalt chloride
as indicator.
Description – Vitreous, amorphous granules, of variable granulometry, with granules impregnated
with adsorption capacity indicator of blue to pink color.
Conservation – In hermetic containers.
Storage – Protect from humidity.
Category – Desiccant.
Silica-gel “G”
CAS – [112926-00-8].
Synonym – Silica gel “G”.
Specification – Contains, approximately, 13.0% (w/w) calcium sulfate hemihydrate.
Description – White fine powder with variable granulometry between 10 μm and 40 μm,
homogeneous.
Physical characteristic – The pH (5.2.19) of the 10% (w/v) suspension in carbon dioxide-free water,
obtained by stirring during 15 minutes is of, approximately, 7.0.
Conservation – In tightly closed containers.
Category – Support to chromatography.
Silica-gel “GF254”
Synonym – Silica gel “GF254”.
Specification – Contains, approximately, 13.0% (w/w) of calcium sulfate hemihydrate and
approximately 1.5% (w/w) of maximum fluorescence intensity indicator at 254 nm.
Description – White fine powder with variable granulometry between 10 μm and 40 μm,
homogeneous.
Physical characteristic – As described for silica-gel “G”.
Conservation – In tightly closed containers.
Category – Support to chromatography.
Silica-gel “H”
Synonym – Silica gel “H”.
Description – White fine powder, with variable granulometry between 10 μm and 40 μm,
homogeneous.
Physical characteristic – As described for silica-gel “G”.
Conservation – In tightly closed containers.
Category – Support to chromatography.
Silica-gel “HF254”
Synonym – Silica gel “HF254”.
Specification – Contains, approximately, 1.5% (w/v) of maximum fluorescence intensity indicator at
254 nm.
Description – White fine powder with variable granulometry between 10 μm and 40 μm,
homogeneous.
Physical characteristic – As described for silica-gel “G”.
Conservation – In tightly closed containers.
Category – Support to chromatography.
Kieselguhr silica
Description – White or light yellow powder.
Solubility – Practically insoluble in water, diluted acid solutions and organic solvents.
Jeffrey’s solution
Preparation – Mix equal parts of 10% (w/v) nitric acid and 10% (w/v) chromic acid.
Conservation – In tightly closed containers.
Karl-Fischer solution
Synonym – Sulfur iodine reagent.
Specification – Comprised of two solutions.
Solution 1: add to a water-free mixture of 70 mL of methyl alcohol with 35 mL of pyridine, under
refrigeration and with absence of humidity, dry sulfur dioxide until obtaining a weight increase of 9
g. Homogenize.
Solution 2: contains 12.6 g of iodine in 100 mL of solution with methyl alcohol.
Conservation – In hermetic containers.
Stability – Decomposes continuously.
Storage – Protect from humidity and from light. Keep under refrigeration.
Safety – Toxic. Flammable.
Additional information – For determination of water content.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Reducer solution
Preparation – Dissolve 5 g of sodium tetrahydroborate in 500 mL of 1% (w/v) sodium hydroxide.
Bismuth subnitrate
CAS – [1304-85-4].
Synonym – Bismuth oxynitrate.
Molecular formula and molar mass – Bi5O(OH)9(NO3)4 – 1461.98.
Specification – It is a basic salt that contains, at minimum, the equivalent to 79.0% of bismuth trioxide
(Bi2O3) (w/w).
Description – White, dense, hygroscopic, odorless and insipid powder. Presents alkaline reaction with
litmus paper.
Solubility – Practically insoluble in water.
Conservation – In tightly closed containers.
Storage – Protect from light.
Therapeutic class – Antacid.
Platelet substitute
Preparo – Add to an amount between 0.5 g and 1 g of phospholipids 20 mL of acetone and frequently
shake the mixture for two hours. Centrifuge for two minutes and eliminate the supernatant liquid. Dry
the residue with the help of a water suction pump, add 20 mL of chloroform and shake for two hours.
Filter under reduced pressure and suspend the residue obtained in 5 mL to 10 mL of 0.9% (w/v)
sodium chloride solution.
Determination of Factor IX activity – Prepare a dilution in 0.9% (w/v) sodium chloride solution, in
such a way that the difference between the coagulation times from successive dilutions of the
reference preparation is approximately 10 seconds.
Conservation – Diluted suspensions can be used for six weeks after the preparation, if preserved at -
30 °C.
Plasma substrate
Preparation – Separate the plasma from human or bovine blood collected at 1/9 of its volume from
3.8% (w/v) sodium citrate solution, or at 2/7 of its volume from a solution with 2% (w/v) sodium acid
citrate and 2.5% (w/v) glucose. On the first case, the substrate is prepared on the day blood is
collected; on the latter case, plasma substrate can be prepared within two days after the collection.
Conservation – In plastic tubes, in small amounts, at a temperature of no more than
-20 °C.
Plasma substrate 1
Preparation – Use hydrophobic equipment made of appropriate plastic material or silicone glass for
collecting and handling blood. From an adequate number (no less than five) of sheep, alive or during
the slaughter, collect an appropriate volume of blood from each animal (a volume of 285 mL of blood
collected over 15 mL of anticoagulant solution is considered appropriate) The collection is made
through a needle adapted to a cannula with sufficient length to reach the bottom of the collecting
container. Reject the first milliliters and collect only blood that flows freely. Mix the blood with a
sufficient amount of anticoagulant solution with 8.7 g of sodium citrate and 4 mg of aprotinin in
100 mL of water, to obtain a final ratio of 19 volumes of blood to 1 volume of anticoagulant solution.
During and immediately after the collection, make a rotation movement with the container to mix
without forming foam. As soon as the collection is finished, close the flask and let it cool down to
10 °C – 15 °C. After cooling, gather the content from all flasks, except from the ones that present
evident signs of hemolysis or coagulation, and keep the blood collected at 10 °C to 15 °C. As soon as
possible and within four hours after the collection, centrifuge the blood collected at 1000 g – 2000 g
at 10 °C to 15 °C, for 30 minutes. Separate the supernatant liquid and centrifuge it at 5000 g, for 30
minutes. If necessary, perform a faster centrifugation, at 20,000 g, for example, for 30 minutes, to
clarify the plasma (do not use filtration processes). Separate the supernatant liquids and immediately
mix, carefully, and distribute the plasma substrate to small containers, which must be closed at the
end of the procedure, in sufficient amounts that allow complete heparin titration (for example, 10 mL
to 30 mL). Immediately freeze, quickly, at a temperature below -70 °C (for example, immersing the
containers in liquid nitrogen) and keep at a temperature below -30 °C. The plasma prepared in these
conditions can be used as plasma substrate in heparin titration if a coagulation time that is appropriate
to the detection method used is obtained in the titration conditions and if reproducible dose-response
/ log curves with major slope are obtained. At the moment of use, thaw a certain amount of plasma
substrate in water bath at 37 °C, slowly mixing until complete liquefaction. Once liquefied, the
plasma must be maintained at 10 °C to 20 °C and used immediately. The thawed plasma substrate
can be slightly centrifuged, if necessary (do not use filtration processes).
Plasma substrate 2
Preparation – Prepare from human blood that has Factor IX content below 1% of the normal content.
Collect blood at 1/9 of its volume from a 3.8% (w/v) sodium citrate solution. Conservation – In plastic
tubes, in small amounts, at a temperature of no more than
-30 °C.
Sudan III
CAS – [85-86-9].
Molecular formula and molar mass– C22H16N4O – 352.40.
Description – Brown-red powder.
Conservation – In tightly closed containers.
Sudan III RS
Preparation – Dissolve 0.5 g of Sudan III in 100 mL of 80% (v/v) ethyl alcohol, heated at 60 °C, cool
down and filter.
Sudan IV
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
CAS – [85-83-6].
Molecular formula and molar mass – C24H20N4O – 380.45.
Description – Brown or red-brown powder.
Physical characteristics – Melting range: 181 °C to 188 °C. Decomposes completely at 260 °C.
Solubility – Practically insoluble in water, soluble in paraffin and phenol, slightly soluble in acetone
and in ethyl alcohol.
Conservation – In tightly closed containers.
Sudan IV RS
Preparation – Dissolve 2 g of Sudan IV in 100 mL of 92% (v/v) ethyl alcohol, heated at 60 °C, cool
down and add 5 mL of glycerin.
Ammonium sulfamate
CAS – [7773-06-0].
Molecular formula and molar mass – NH4SO3NH2 – 114.13.
Description – White crystalline powder or colorless crystals.
Physical characteristic – Melting temperature: approximately 131 °C.
Solubility – Very soluble in water and slightly soluble in ethyl alcohol.
Conservation – In perfectly closed containers.
Sulfanilamide
CAS – [63-74-1].
Synonym – 4-Aminobenzenesulfonamide.
Molecular formula and molar mass – C6H8N2O2S – 172.20.
Description – Crystals or fine white or yellow-white powder.
Physical characteristic – Melting temperature: approximately 165 °C.
Solubility – Soluble in glycerol and practically insoluble in chloroform and in ethyl ether.
Conservation – In tightly closed containers.
Therapeutic class – Antibacterial.
Ceric sulfate
CAS – [13590-82-4].
Synonym – Cerium disulfate.
Molecular formula and molar mass – Ce(SO4)2 – 332.23.
Description – Orange-yellow crystal or powder.
Physical characteristic – Melting temperature: approximately 350 °C.
Conservation – Protect from light, heat and humidity.
Safety – Toxic and oxidizing agent.
Specification – Contains no less than 98.5% (w/w) in relation to the substance desiccated at 250 °C.
Description – Blue crystals, powder or granules. Slowly effloresces in contact with air.
Physical characteristic – Heated at 250 °C until constant weight, loses 33.0% to 36.5% of its weight.
Solubility – Very soluble in water and slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from air.
Safety – Irritant.
Cupric sulfate RS
Specification – Contains 12.5 g of cupric sulfate pentahydrate in 100 mL of aqueous solution.
Conservation – In tightly closed containers.
Ammonium sulfate
CAS – [7783-20-2].
Molecular formula and molar mass – (NH4)2SO4 – 132.13.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless, odorless crystals.
Physical characteristic – Decomposes at temperatures above 280 °C.
Solubility – Very soluble in water, practically insoluble in acetone and in ethyl alcohol.
Conservation – In tightly closed containers.
Barium sulfate
CAS – [7727-43-7].
Molecular formula and molar mass – BaSO4 – 233.39.
Specification – Contains no less than 97.5% (w/w).
Description – White, fine, dense powder. Odorless and insipid.
Solubility – Practically insoluble in water, in organic solvents and in acids and alkali hydroxide
solutions.
Conservation – In tightly closed containers.
Therapeutic class – Radiology contrast for gastrointestinal tract.
Cadmium sulfate
CAS – [7790-84-3].
Molecular formula and molar mass – 3CdSO4.8H2O – 769.52.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless, odorless crystalline powder.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Calcium sulfate RS
Preparation – Shake 5 g of calcium sulfate hemihydrate with 100 mL of water, for one hour. Filter
before use.
Conservation – In tightly closed containers.
N,N-dimethyl-p-phenylenediamine sulfate
CAS – [536-47-0].
Synonym – N,N-dimethyl-1,4-benzenediamine sulfate.
Molecular formula and molar mass – C8H12N2.H2SO4 – 234.28.
Physical characteristic – Melting range: 200 °C to 205 °C, with decomposition.
Storage – Protect from light.
Safety – Toxic.
Dimethyl sulfate
CAS – [77-78-1].
Synonyms – Dimethyl sulfate, DMS.
Molecular formula and molar mass – (CH3)2SO4 – 126.13.
Description – Colorless liquid.
Physical characteristics – Boiling temperature: approximately 188 °C, with decomposition.
Refractive index (20 °C): 1.3874.
Miscibility – Miscible with water (with hydrolysis) and with ethyl ether and acetone.
Conservation – In closed containers.
Safety – Corrosive. Poisonous!
Hydrazine sulfate
CAS – [10034-93-2].
Molecular formula and molar mass – H6N2O4S – 130.12.
Description – Colorless crystals.
Solubility – Moderately soluble in cold water, soluble in hot water (50 °C) and freely soluble in water
in ebullition. Practically insoluble in ethyl alcohol.
Lithium sulfate
CAS – [10102-25-7].
Molecular formula and molar mass – Li2SO4.H2O – 127.95.
Description – Colorless crystals.
Solubility – Freely soluble in water and practically insoluble in ethyl alcohol.
Description – White crystalline powder or colorless brilliant crystals, of saline flavor, soluble in
water, very soluble in water in ebullition, practically insoluble in ethyl alcohol.
Conservation – In tightly closed containers.
Manganese sulfate
CAS – [10101-68-5].
Molecular formula and molar mass – MnSO4.4H2O – 223.05.
Specification – Contains no less than 98.0% (w/w) of MnSO4, in relation to the substance desiccated
at temperature between 450 °C and 500 °C
Description – Pink crystals or crystalline powder. Odorless. Effloresces slowly.
Physical characteristic – Loses water at approximately 450 °C.
Solubility – Freely soluble in water, very soluble in water in ebullition and practically insoluble in
ethyl alcohol.
Conservation – In tightly closed containers.
Additional information – The commercial product is usually a mixture of manganese sulfate
tetrahydrate and pentahydrate.
4-methylaminophenol sulfate
CAS – [55-55-0].
Molecular formula and molar mass – C14H20N2O6S – 344.38.
Description – Colorless crystals.
Physical characteristic – Melting temperature: approximately 260 °C, with decomposition.
Solubility – Very soluble in water and slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light.
4-methylaminophenol sulfate RS
Preparation – Dissolve 0.35 g of 4-methylaminophenol sulfate in 50 mL of water. Add 20 g of
sodium bisulfite and homogenize. Dilute to 100 mL with water.
Potassium sulfate
CAS – [7778-80-5].
Molecular formula and molar mass – K2SO4 – 174.25.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Colorless crystals or white crystalline powder, with bitter flavor.
Physical characteristics – Aqueous solution with neutral character. Melting temperature: 1067 °C.
Conservation – In closed containers.
Protamine sulfate
CAS – [9009-65-8].
Specification – Consists of mixture of simple proteins, obtained from sperm and testicles of adequate
species of fish. It has the property of neutralizing heparin.
Description – White or faintly colored, fine, crystalline or amorphous powder.
Conservation – In tightly closed containers, under refrigeration.
Storage – Protect from heat.
Sodium sulfate
CAS – [7757-82-6].
Molecular formula and molar mass – Na2SO4 – 142.04.
Specification – Prepared from Na2SO4.10H2O by heating at, approximately, 100 °C. Contains no less
than 99.0% (w/w) in relation to the desiccated substance.
Description – White, odorless, fine powder, of salty and faintly bitter flavor. Hygroscopic.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Tetrabutylammonium sulfate
CAS – [32503-27-8].
Synonyms – N,N,N-tributyl-1-butanaminium sulfate, tetrabutylammonium hydrogen sulfate
Molecular formula and molar mass – C16H36N.HSO4 – 339.54.
Description – White crystalline powder.
Physical characteristic – Melting range: 169 °C to 173 °C.
Solubility – Freely soluble in water and in methyl alcohol.
Ferric sulfate
CAS – [10028-22-5].
Synonym – Ferric persulfate.
Molecular formula and molar mass – Fe2(SO4)3.xH2O.
Specification – The commercial product usually contains approximately 20% (w/w) of water.
Description – White to yellow powder, very hygroscopic; decomposes in presence of air.
Solubility – Slightly soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Storage – Protect from light and from air.
Ferrous sulfate RS
Specification – Contains 8% (w/v) of ferrous sulfate heptahydrate in cold, recently boiled water.
Prepare immediately before use.
Conservation – In tightly closed containers.
Storage – Protect from light, from air and from heat.
Ammonium sulfide RS
Preparation – Saturate 60 mL of ammonia RS with hydrogen sulfide and add 40 mL of ammonia RS.
Prepare immediately before use.
Conservation – In a small, full and tightly closed container.
Storage – Protect from light and from heat.
Stability – In case of abundant sulfur precipitation, discard the solution.
Hydrogen sulfide
CAS – [7783-06-4].
Synonym – Hydrosulfuric acid.
Molecular formula and molar mass – H2S – 34.08.
Specification – Produced by treatment f ferrous sulfide (or other sulfides) with diluted sulfuric acid
or hydrochloric acid.
Description – Colorless gas with characteristic odor and sweet flavor; denser than air.
Physical characteristics – Vapor density: 1.19. Ignition temperature: 260 °C.
Safety – Flammable. Toxic. Poison!
Hydrogen sulfide RS
Specification – The aqueous solution saturated at 20 °C contains approximately 0.4 to 0.5% (w/v).
Prepared by the passage of hydrogen sulfide in cold water.
Physical characteristic – the pH (5.2.19) of the freshly prepared aqueous solution is 4.5.
Stability – Prepare immediately before use.
Safety – Flammable. Toxic. Poison!
Sodium sulfide
CAS – [1313-84-4].
Molecular formula and molar mass – Na2S.9H2O – 240,18.
Description – Colorless deliquescent crystals, which turn yellow by exposure to air or by action from
light. Odor similar to hydrogen sulfide.
Physical characteristic – Melting temperature: approximately 50 °C.
Conservation – Tightly closed container, in a cold place.
Storage – Protect from air, light and heat.
Sodium sulfide RS
Specification – Contains 10% (w/v) of sodium sulfide in water.
Stability – Prepare immediately before use.
Sodium sulfite
CAS – [7757-83-7].
Molecular formula and molar mass – Na2SO3 – 126.04.
Description – White or nearly white odorless powder.
Solubility – Freely soluble in water and very slightly soluble in ethyl alcohol.
Conservation – In tightly closed containers.
Tannin
CAS – [1401-55-4].
Synonym – Tannic acid.
Specification – Obtained from the bark of different plants, consisting especially of a mixture of
polyphenolic substances.
Description – Yellow to brown powder. Faintly characteristic odor and astringent flavor. Solubility –
Very soluble in water, freely soluble in ethyl alcohol and soluble in acetone. Conservation – In tightly
closed containers.
Storage – Protect from light.
Labelling – The labeling must indicate the botanical source.
Sodium tartrate
CAS – [6106-24-7].
Molecular formula and molar mass – C4H4O6Na2.2H2O – 230.08.
Specification – Contains 84.34% of C4H4O6Na2 and 15.66% of water. Heated at 150 °C, loses a
minimum of 15.6% and a maximum of 15.7% of its weight.
Description – White or nearly white crystals.
Solubility – Freely soluble in water and practically insoluble in ethyl alcohol.
Conservation – In tightly closed containers.
Ferrous tartrate RS
Preparation – Dissolve 1 g of ferrous sulfate heptahydrate, 2 g of potassium sodium tartrate and 0.1 g
of sodium bisulfite in water. Complete the volume to 100 mL with water. Prepare immediately before
use.
Sodium tetraborate
CAS – [1303-96-4].
Synonyms – Sodium borate, di-sodium tetraborate, borax.
Molecular formula and molar mass– Na2B4O7.10H2O – 381.37.
Specification – Contains no less than 99.0% (w/w).
Description – Colorless crystals or white crystalline powder, odorless, with caustic flavor.
Efflorescent. Solubility – Soluble in water, very soluble in water in ebullition and freely soluble in
glycerol. Conservation – In tightly closed containers; effloresces on dry air.
Storage – Protect from air.
Carbon tetrachloride
CAS – [56-23-5].
Molecular formula and molar mass – CCl4 – 153.82.
Specification – Contains no less than 99.0% (w/w).
Description – Clear, colorless, dense liquid, with characteristic odor.
Physical characteristics – Boiling range: 76 °C to 77 °C. Density: 1.588 to 1.590. Refractive index
(20 °C): 1.4607.
Solubility – Practically insoluble in water; miscible in ethyl alcohol.
Conservation – In hermetic containers.
Storage – Protect from light and from heat.
Safety – Poison (in liquid and gaseous forms)!
Additional information – It is not flammable, but releases phosgene (toxic) in presence of flame.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Tetradecane
CAS – [629-59-4].
Molecular formula and molar mass – C14H30 – 198.39.
Specification – Contains no less than 99.5% (w/w).
Description – Clear and colorless liquid.
Physical characteristics – Density (20 °C): approximately 0.76. Refractive index (20 °C):
approximately 1.429. Melting temperature: approximately -5 °C. Boiling temperature: approximately
252 °C.
Conservation – In closed containers.
Sodium tetraphenylborate
CAS – [143-66-8].
Molecular formula and molar mass – NaB(C6H5)4 – 342.22.
Description – White or nearly white powder or crystals.
Solubility – Freely soluble in water and in acetone.
Conservation – In tightly closed containers.
Sodium borohydride
CAS – [16940-66-2].
Molecular formula and molar mass – NaBH4 – 37.83.
Description – Colorless and hygroscopic crystals.
Solubility – Freely soluble in water, soluble in absolute ethyl alcohol.
Storage – In tightly closed containers.
3,3’-Diaminobenzidine tetrahydrochloride
CAS – [7411-49-6].
Molecular formula and molar mass – C12H18Cl4N4– 360.12.
Description – White or yellow, occasionally purple crystals.
Physical characteristic – Melting temperature: approximately 280 °C, with decomposition.
Solubility – Soluble in water.
Conservation – In tightly closed containers, under refrigeration.
Safety – Irritant.
3,3’-Diaminobenzidine tetrahydrochloride RS
Specification – Contains 1 g of 3,3’-diaminobenzidine tetrahydrochloride in 200 mL of water.
Conservation – In tightly closed containers, under refrigeration.
Safety – Irritant.
Tetrahydrofuran
CAS – [109-99-9].
Molecular formula and molar mass – C4H8O – 72.11.
Specification – The product is added with stabilizers (p-cresol, hydroquinone) in the ratio of 0.05%
to 0.1% (w/v), to avoid excessive formation of peroxides.
Description – Colorless liquid. Intense odor similar to ethyl ether.
Physical characteristics – Boiling temperature: 65 °C to 66 °C. Density (20 °C): approximately
0.889. Refractive index (20 °C): 1.4070.
Miscibility – Miscible with water and ethyl alcohol.
Conservation – In small, tightly closed and full containers.
1,1,3,3-Tetramethylbutylamine
CAS – [107-45-9].
Molecular formula and molar mass – C8H19N – 129.25.
Description – Colorless and clear liquid.
Physical characteristics – Density (20 °C): approximately 0.805. Refractive index (20 °C):
approximately 1.424. Boiling temperature: approximately 140 °C.
Tetramethylethylenediamine
CAS – [110-18-9].
Synonyms – N,N,N’,N’-Tetramethylethylenediamine, TEMED.
Molecular formula and molar mass – C6H16N2 –116.21.
Specification – Appropriate quality for electrophoresis.
Description – Colorless liquid.
Physical characteristics – Density (20 °C): approximately 1.418. Boiling temperature: approximately
121 °C.
Miscibility – Miscible with water, with ethyl alcohol and with ethyl ether.
Potassium tetraoxalate
CAS – [6100-20-5].
Molecular formula and molar mass– C4H3KO8.2H2O – 254.19.
Description – White crystalline powder or colorless or white crystals.
Solubility – Moderately soluble in water and soluble in water in ebullition, slightly soluble in ethyl
alcohol.
Conservation – In tightly closed containers.
Osmium tetroxide
CAS – [20816-12-0].
Molecular formula and molar mass – OsO4 – 254.20.
Description – Yellow crystalline mass, or light yellow needles, hygroscopic, sensitive to light.
Solubility – Soluble in water, ethyl alcohol and ethyl ether.
Conservation – In hermetic containers.
Safety – Poisonous vapors!
Osmium tetroxide RS
Specification – Contains 0.25% (w/v) of osmium tetroxide in 0.05 M sulfuric acid.
Conservation – In tightly closed containers.
Thiomersal
CAS – [54-64-8].
Molecular formula and molar mass – C9H9HgNaO2S – 404.81.
Description – Light yellow crystalline powder.
Solubility – Very soluble in water and freely soluble in ethyl alcohol.
Thymidine
CAS – [50-89-5].
Synonym – 1-(2-Deoxy-β-D-ribofuranosyl)-5-methyluracil.
Molecular formula and molar mass – C10H14N2O5 – 242.23.
Description – Needle-shaped crystals or white powder.
Solubility – Soluble in water, in hot ethyl alcohol and in glacial acetic acid.
Thymine
CAS – [65-71-4].
Synonym – 5-Methyl-2,4-(1H,3H)-pyrimidinedione.
Molecular formula and molar mass – C5H6N2O2 – 126.12.
Description – Small needle-shaped crystals or plates.
Solubility – Slightly soluble in cold water, soluble in hot water. Dissolves in diluted alkali hydroxide
solutions.
Thymol
CAS – [89-83-8].
Synonym – 5-Methyl-2-(1-methylethyl)phenol.
Molecular formula and molar mass – C10H14O – 150.22.
Description – Colorless crystals, with aromatic odor.
Physical characteristic – Melting temperature: approximately 50 °C.
Solubility – Very slightly soluble in water, very soluble in ethyl alcohol, freely soluble in essential
oils and in fatty oils, moderately soluble in glycerol. Dissolves in alkali hydroxide solutions.
Thioacetamide
CAS – [62-55-5].
Molecular formula and molar mass– C2H5NS –75.13.
Description – White or nearly white crystalline powder or crystals. Faint odor of mercaptan.
Physical characteristic – Melting temperature: 113 °C to 114 °C.
Solubility – Freely soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Thioacetamide RS
Preparation – Mix 0.2 mL of the 4% (w/v) thioacetamide solution with 1 mL of the following
mixture: 1.5 mL of M sodium hydroxide, 0.5 mL of water and 2 mL of 85% (w/v) glycerol. Heat in
a water bath for 20 seconds.
Stability – Prepare immediately before use.
Ammonium thiocyanate
CAS – [1762-95-4].
Synonym – Ammonium rhodanide.
Molecular formula and molar mass – NH4SCN – 76.12.
Description – Colorless and deliquescent crystals.
Physical characteristic – Melting temperature: approximately 149 °C.
Solubility – Very soluble in water and soluble in ethyl alcohol.
Conservation – In hermetic containers.
Storage – Protect from humidity.
Ammonium thiocyanate RS
Specification – Contains 8% (w/v) of ammonium thiocyanate in water.
Conservation – In tightly closed containers.
Mercury thiocyanate
CAS – [592-85-8].
Molecular formula and molar mass – Hg(SCN)2 – 316.76.
Description – White or nearly white crystalline powder.
Solubility – Very soluble in water, slightly soluble in ethyl alcohol, soluble in sodium chloride
solutions.
Conservation – In tightly closed containers.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Mercury thiocyanate RS
Preparation – Dissolve 0.3 g of mercury thiocyanate in ethyl alcohol. Complete the volume to 100
mL with the same solvent.
Conservation – In tightly closed containers.
Stability – Limited to one week.
Potassium thiocyanate
CAS – [333-20-0].
Synonym – Potassium rhodanide.
Molecular formula and molar mass – KSCN – 97.18.
Specification – Contains no less than 99.0% (w/w).
Physical characteristic – Melting temperature: approximately 173 °C.
Solubility – Very soluble in water and in ethyl alcohol.
Conservation – In tightly closed containers.
Safety – May cause skin rashes.
Sodium thioglycolate
CAS – [367-51-1].
Molecular formula and molar mass – C2H3NaO2S – 114.09.
Specification – Contains no less than 95.0% (w/w).
Description – White, hygroscopic crystalline powder, with characteristic faint odor. Oxidizes in
contact with air.
Solubility – Freely soluble in water and in methyl alcohol, slightly soluble in ethyl alcohol.
Conservation – In hermetic containers.
Storage – Protect from light and from air.
Thionine RS
Preparation – Add 1 g of thionine to 2.5 g of phenol and complete the volume to 100 mL with water.
Conservation – In closed containers.
Thionine RS1
Preparation: prepare a 0.2% thionine acetate solution in 25% (v/v) ethyl alcohol by immersing the
dry sample in the solution. After 15 minutes, wash the excess reagent with 25% (v/v) ethyl alcohol.
Sodium thiosulfate
CAS – [10102-17-7].
Synonym – Sodium hyposulfite R.
Molecular formula and molar mass – Na2S2O3.5H2O – 248.17.
Specification – Contains no less than 99.0% (w/w) in relation to the desiccated substance.
Description – Colorless crystals, or white crystalline powder, easily efflorescent, with faintly bitter
flavor.
Physical characteristics – Melting temperature: approximately 48 °C. Dissolves in its own
crystallization water, at temperature of approximately 49 °C.
Solubility – Very soluble in water, practically insoluble in ethyl alcohol.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Thiourea
CAS – [62-56-6].
Molecular formula and molar mass – CH4N2S – 76.12.
Description – White or nearly white crystalline powder or crystals.
Physical characteristic – Melting range: from 176 °C to 178 °C.
Solubility – Soluble in water and in ethyl alcohol.
Conservation – In closed containers.
Tyrosine
CAS – [60-18-4].
Molecular formula and molar mass – C9H11NO3 – 181.19.
Description – Colorless, white or nearly white crystals, or white or nearly white crystalline powder.
Solubility – Slightly soluble in water, practically insoluble in acetone and in ethyl alcohol, soluble in
diluted hydrochloric acid and alkali hydroxide solutions.
p-Tolualdehyde
CAS – [104-87-0].
Molecular formula and molar mass – C8H8O – 120.15.
Description – Colorless or yellow clear liquid.
Physical characteristic – Refractive index (20 °C): between 1.544 and 1.546.
Toluene
CAS – [108-88-3].
Synonym – Methylbenzene, toluol.
Molecular formula and molar mass – C7H8 – 92.14.
Description – Colorless liquid with characteristic odor.
Physical characteristics – Boiling temperature: 110 °C to 111 °C. Density: approximately 0.87.
Refractive index (20 °C): 1.4967.
Solubility – Very slightly soluble in water; miscible with ethyl alcohol.
Safety – Toxic. Flammable.
p-Toluidine
CAS – [106-49-0].
Synonym – 4-Methylaniline.
Molecular formula and molar mass – C7H9N – 107.16.
Description – White or slightly yellow flakes or crystals.
Physical characteristics – Melting temperature: approximately 44 °C. Density (20 °C): 1.046.
Solubility – Freely soluble in ethyl alcohol, methyl alcohol, acetone and in diluted acids, and slightly
soluble in water.
Conservation – In tightly closed containers.
Thorin
CAS – [3688-92-4].
Synonym – Thoron.
Molecular formula and molar mass – C16H11AsN2Na2O10S2–576.30.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Thorin RS
Preparation – Dissolve 0.2% (w/v) thorin in water.
Conservation – In closed container.
Storage – Protect from light.
Stability – Use within one week after the preparation.
Tricine
CAS – [5704-04-1].
Molecular formula and molar mass – C6H13NO5 – 179.17.
Specification – Appropriate quality for electrophoresis.
Physical characteristic – Melting temperature: approximately 183 °C.
1,1,1-Trichloroethane
CAS – [71-55-6].
Molecular formula and molar mass – C2H3Cl3 – 133.40.
Description – Non-flammable liquid.
Physical characteristics – Density (20 °C): approximately 1.34. Boiling temperature: approximately
74 °C.
Solubility – Practically insoluble in water, soluble in acetone and in methyl alcohol.
Trichlorethylene
CAS – [79-01-6].
Synonym – Trichloroethene.
Molecular formula and molar mass – C2HCl3 – 131.39.
Specification – Contains no less than 99.5% (w/w).
Description – Colorless liquid, characteristic odor.
Physical characteristics – Density (20 °C): approximately 1.46. Refractive index (20 °C):
approximately 1.477. Boiling temperature: approximately 87 °C.
Solubility – Practically insoluble in water, soluble in acetone and in methyl alcohol.
Conservation – In tightly closed containers.
Safety – Toxic.
Triethanolamine
CAS – [102-71-6].
Synonym – 2,2’,2”-nitrilotriethanol.
Molecular formula and molar mass – C6H15NO3 – 149.19.
Description – Colorless, viscous, very hygroscopic liquids, turns brown by exposure to air.
Physical characteristic – Density: approximately 1.13.
Miscibility – Miscible with water, acetone, ethyl alcohol and methyl alcohol.
Conservation – In tightly closed containers protected from light.
Triethylamine
CAS – [121-44-8].
Molecular formula and molar mass – C6H15N – 101.19.
Description – Colorless liquid, with strongly ammoniacal odor.
Physical characteristics – Density: approximately 0.727. Boiling range: 89 °C to 90 °C.
Conservation – In tightly closed containers.
Safety – Irritant. Flammable.
Triphenylmethanol
CAS – [76-84-6].
Molecular formula and molar mass – C19H16O – 260.34.
Description – Colorless crystals or white or nearly white powder.
Solubility – Practically insoluble in water and freely soluble in ethyl alcohol.
Conservation – In tightly closed containers
Boron trifluoride
CAS – [7637-07-2].
Molecular formula and molar mass – BF3 – 67.81.
Description – Colorless gas, with pungent, suffocating odor.
Trinitrophenol RS
Use picric acid RS1.
Arsenic trioxide
CAS – [1327-53-3].
Synonym – Arsenous acid.
Molecular formula and molar mass – As2O3 – 197.84.
Description – White or clear crystalline powder or amorphous mass.
Solubility – Slightly soluble in water and soluble in water in ebullition.
Conservation – In tightly closed containers.
Safety – Poison!
Chromium trioxide.
CAS – [1333-82-0].
Synonym – Chromic anhydride.
Molecular formula and molar mass – CrO3 – 99.99.
Description – Red-brown scales or granulated powder or crystals, deliquescent.
Physical characteristic – Melting temperature: approximately 197 °C.
Solubility – Very soluble in water.
Conservation – In hermetic glass containers.
Storage – Avoid proximity to flammable items.
Safety – Energetic oxidizing agent. Irritant.
Bovine thrombin
CAS – [9002-04-4].
Specification – Biological preparation obtained from bovine plasma, with an enzyme that converts
fibrinogen into fibrin.
Description – Yellow-white powder.
Conservation – In closed containers.
Storage – At temperatures below 0 °C.
Human thrombin
CAS – [9002-04-4].
Specification – Biological preparation obtained from human plasma, by appropriate fractioning
techniques.
Description – Cream-colored amorphous powder.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Conservation – In tightly closed containers, under refrigeration, specifying the preparation date and
potency.
Storage – Protect from light, humidity and from oxygen.
Category – Enzyme. Local hemostatic.
Thromboplastin
CAS – [9035-58-9].
Synonym – Factor III (blood coagulation).
Specification – Biological preparation of animal origin, obtained by extraction of certain organs:
brain, lung.
Description – Yellow powder or suspension, with characteristic odor.
Physical characteristic – In the presence of appropriate calcium ion concentrations, it presents
thrombokinase activity in blood coagulation.
Conservation – In hermetic containers.
Labeling – Specify in the composition: ions and antimicrobial agents, their concentrations, as well as
origin, date of preparation and activity.
Storage – Protect from heat and humidity. Keep under refrigeration.
Category – Preparation with enzymatic activity. Local hemostatic.
Thromboplastin, reagent
Preparation – Shake 1.5 g of ox brain powder dried with acetone, with 60 mL of water at 50 °C, for
10 to 15 minutes. Centrifuge at 1500 rpm for two minutes and decant the supernatant liquid.
Conservation – The extract,stored at temperature below 0 °C, maintains the activity for several days.
Cresol may be added, in the amount of 3 g/L, as antimicrobial agent.
Tromethamine
CAS – [77-86-1].
Molecular formula and molar mass – C4H11NO3 – 121.14.
Synonym –Trometamol, tris(hydroxymethyl)aminomethane.
Specification – Contains no less than 99.0% in relation to the desiccated substance.
Description – White or nearly white crystalline powder or crystals.
Physical characteristics – Melting range: 168 °C to 172 °C. The pH (5.2.19) of the 0.1 M
tromethamine solution is 10.4.
Solubility – Freely soluble in water, moderately soluble in ethyl alcohol and very slightly soluble in
ethyl acetate.
Conservation – In tightly closed containers.
Sodium tungstate
CAS – [10213-10-2].
Molecular formula and molar mass – Na2WO4.2H2O – 329.85.
Description – Colorless crystals or white or nearly white crystalline powder.
Solubility – Freely soluble in water, forming a clear solution, and practically insoluble in ethyl
alcohol.
Urea
CAS – [57-13-6].
Synonym – Carbamide.
Molecular formula and molar mass – (NH2)2CO – 60.06.
Description – White crystals or powder, strong odor.
Physical characteristic – Melting temperature: approximately 132.7 °C.
Solubility – Very soluble in water, soluble in ethyl alcohol and practically insoluble in methylene
chloride.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Ammonium vanadate
CAS – [7803-55-6].
Molecular formula and molar mass – NH4VO3 – 116.98.
Description – White or light yellow crystalline powder.
Solubility – Slightly soluble in water.
Vanillin
CAS – [121-33-5]
Molecular formula and molar mass – C8H8O3 – 152.15.
Description – Needle-shaped crystals, or white or yellow crystalline powder.
Physical characteristic – Melting range: between 81 °C and 84 °C.
Solubility – Slightly soluble in water, freely soluble in ethyl alcohol and methyl alcohol.
Conservation – In tightly closed containers.
Vanillin RS
Preparation – Dissolve 1 g of vanillin in ethyl alcohol and complete the volume to 100 mL with the
same solvent. Carefully add 2 mL of sulfuric acid and homogenize. Use the solution within 48 hours.
Sulfuric vanillin RS
Preparation – Dissolve 1 g of vanillin in 100 mL of methyl alcohol. Add 4 mL of hydrochloric acid
and 5 mL of sulfuric acid.
Warfarin sodium
CAS – [129-06-6].
Molecular formula and molar mass – C19H15NaO4 – 330.31.
Specification – Contains no less than 97.0% (w/w) in relation to the desiccated substance.
Description – Crystalline or amorphous powder, with faintly bitter flavor.
Solubility – Very soluble in water and in ethyl alcohol, soluble in acetone, very soluble in methylene
chloride.
Conservation – In tightly closed containers.
Storage – Protect from light.
Therapeutic class – Anticoagulant.
Bromocresol green RS
Solution A – Dissolve 0.2 g of bromocresol green in 30 mL of water and 6.5 mL of 0.1 M sodium
hydroxide.
Solution B – Dissolve 38 g of monobasic sodium phosphate and 2 g of sodium phosphate dibasic in
water and complete the volume to 1000 mL with the same solvent.
Preparation – Dilute the Solution A to 500 mL using Solution B as diluent and homogenize. If
necessary, adjust the pH to 4.6 ± 0.1 with 0.1 M hydrochloric acid.
Phenol red RS
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.2-01
Solution A – Dissolve 33 mg of phenol red in 1.5 mL 2 M sodium hydroxide and dilute to 100 mL
with water.
Solution B – Dissolve 25 g of ammonium sulfate in 235 mL of water. Add 105 mL of 2 M sodium
hydroxide and 135 mL of 2 M acetic acid.
Preparation – Add 25 mL of Solution A to Solution B. If necessary, adjust pH to 4.7.
Conservation – In small containers resistant to alkalis.
Vitexin
CAS – [3681-93-4].
Molecular formula and molar mass – C21H20O10 – 432.38.
Description – Yellow powder.
Conservation – In tightly closed containers.
Storage – Protect from exposure to light.
Xanthydrol
CAS – [90-46-0].
Molecular formula and molar mass – C13H10O2 – 198.22.
Specification – Contains no less than 90.0% (w/w) of xanthydrol.
Description – White or light yellow powder.
Solubility – Very soluble in water, soluble in ethyl alcohol and glacial acetic acid.
Storage – Protect from light.
Xylene
CAS – [1330-20-7].
Synonym – Xylol.
Molecular formula and molar mass – C8H10 – 106.17.
Specification – Mixture of isomers: o-xylene, p-xylene and m-xylene, with predominance of m-
xylene.
Description – Clear and colorless liquid.
Physical characteristics – Density (20 °C): approximately 0.867. Refractive index (20 °C):
approximately 1.497. Boiling temperature: approximately 138 °C.
Conservation – In hermetic containers.
Safety – Toxic. Flammable.
Zinc, activated
Preparation – Cover an amount of granulated zinc with chloroplatinic acid solution at 50 mg/mL.
Allow to stand for 10 minutes. After washing, drain and dry immediately.
Conservation – In tightly closed containers.
Zinc, granulated
CAS – [7440-66-6].
Element and atomic mass – Zn – 65.38.
Description – Blue-white lustrous metal. Stable on dry air. Converts into basic carbonate when
exposed to humidity.
Physical characteristics – Becomes malleable between 100 °C and 150 °C. Burns in presence of air,
presenting a blue-green flame.
Conservation – In tightly closed containers.
Storage – Protect from humidity.
Safety – Toxic.
The values obtained in standardization are valid for all pharmacopoeia uses.
The reagents employed must have a chemically pure degree and, when necessary, be submitted to
desiccation. Volumetric solutions are standardized and used at temperatures of approximately 25 °C.
When there are significant variations in temperature, the volumetric solution must have its titration
confirmed at the same temperature or be measured with a correction factor.
M hydrochloric acid VS
Specification – Contains 85 mL of hydrochloric acid in 1000 mL of aqueous solution.
Standardization – Weigh, accurately, about 1.5 g of anhydrous sodium carbonate. Add 100 mL of
water and two drops of methyl red TS. Add acid slowly, from the burette, until a faint pink color.
Heat the solution until boiling, cool down and continue the titration. Repeat this sequence of
operations until heating no longer affects the pink color. Calculate the molarity. Each 52.99 mg of
sodium carbonate is equivalent to 1 mL of M hydrochloric acid.
Conservation – Hermetic containers.
Storage – Protect from heat.
M sulfuric acid VS
Specification – Contains 98.07 g of sulfuric acid in 1000 mL of aqueous solution.
Preparation – Add 800 mL of water to a 1000 mL volumetric flask and carefully add, on the center
of the liquid layer, 54 mL of sulfuric acid. Homogenize, cool down to room temperature, complete
the volume with water and homogenize.
Standardization – Weigh, accurately, about 3 g of anhydrous sodium carbonate. Add 100 mL of water
and two drops of methyl red TS. Add acid slowly, from the burette, until getting a faint pink color.
Heat the solution until boiling, cool down and continue the titration. Repeat this sequence of
operations until heating no longer affects the pink color. Calculate the molarity. Each 105.98 mg of
anhydrous sodium carbonate is equivalent to 1 mL of M sulfuric acid.
0.05 M bromine VS
Preparation – Dissolve 3 g of potassium bromate and 15 g of potassium bromide in water and
complete the volume to 1000 mL with the same solvent. Homogenize.
Standardization – Transfer 25 mL of the bromine solution to a 500 mL Erlenmeyer flask with stopper
and add 120 mL of water. Add 5 mL of hydrochloric acid, put the stopper and softly shake. Add 5 mL
of potassium iodide RS, put the stopper again, shake and allow to stand for five minutes protected
from light. Titrate the released iodine with 0.1 M sodium thiosulfate VS, adding 3 mL of starch TS
near the endpoint. Calculate the molarity. Each mL of 0.05 M bromine VS is equivalent to 1 mL of
0.1 M sodium thiosulfate VS.
Conservation – Tightly closed amber glass containers.
Storage – Protect from light.
Dichlorophenol-indophenol VS
Preparation – Dissolve 50 mg of 2,6-dichlorophenol-indophenol sodium in 50 mL of water with
42 mg of sodium bicarbonate. Shake vigorously. After dissolution, complete the volume to 200 mL
with water and homogenize. Filter.
Standardization – Weigh, accurately, about 50 mg of ascorbic acid, dissolve with metaphosphoric
acetic acid RS and complete the volume to 50 mL with the same solvent. Transfer to a 50 mL flask,
immediately, 2 mL of the ascorbic acid solution and add 5 mL of metaphosphoric acetic acid RS.
Titrate quickly with the dichlorophenol-indophenol solution until the pink color persists for, at least,
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition RG7.3-01
five seconds. Perform a blank titration, titrating 7 mL of metaphosphoric acetic acid RS, added with
an amount of water equal to the amount of dichlorophenol-indophenol solution used in the ascorbic
acid titration. Express the concentration of the volumetric solution in terms of equivalent in mg of
ascorbic acid.
Conservation – Tightly closed amber glass containers.
Stability – Use within three days and standardize immediately before use.
M potassium hydroxide VS
Preparation – Dissolve 60 g of potassium hydroxide in water and complete the volume to 1000 mL
with the same solvent. Add saturated barium hydroxide solution, freshly prepared, until precipitate is
no longer formed. Shake and allow to stand for approximately 12 hours. Decant the clear liquid, or
filter, and transfer to inert material containers (like polyethylene). Standardization – Use the same
procedure adopted for M sodium hydroxide VS. Conservation – In tightly closed, inert containers
(like polyethylene).
Safety – Caustic.
M sodium hydroxide VS
Preparation – Prepare a 50% (w/v) sodium hydroxide solution with carbon dioxide-free water. Cool
to room temperature and allow to settle. Take 82 mL of supernatant and dilute with water, completing
the volume to 1000 mL with the same solvent.
Indigo carmine VS
Preparation – Crush 4 g of indigo carmine with successive portions of water until dissolution,
without exceeding 900 mL. Transfer to a 1000 mL volumetric flask, add 2 mL of sulfuric acid and
complete the volume with water. Homogenize.
Standardization – Add to 10 mL of standard nitrate solution (100 ppm NO3) 10 mL of water, 0.05 mL
of indigo carmine VS and, carefully, 30 mL of sulfuric acid. Titrate immediately with indigo carmine
VS until turning into a stable blue color. The total volume, in mL, of indigo carmine VS required is
equivalent to 1 mg of NO3.
of this solution 2 g of potassium iodide and 10 mL of M sulfuric acid. Titrate with 0.1 M sodium
thiosulfate VS using starch TS, added near the endpoint, as indicator. Each mL of 0.1 M sodium
thiosulfate VS is equivalent to 3.566 mg of KIO3.
0.005 M iodine VS
Preparation – Dissolve approximately 1.3 g of iodine in 10 mL of potassium iodide at 36% (w/v).
Add three drops of hydrochloric acid and complete the volume to 1000 mL with water.
Standardization – Add to 25 mL of iodine solution 1 mL of M hydrochloric acid and titrate with 0.01
M sodium thiosulfate VS until pale yellow color. Add three drops of starch TS and continue with the
titration until the blue color disappears. Calculate the molarity.
Conservation – Tightly closed glass containers.
Storage – Protect from light.
0.05 M iodine VS
Preparation – Dissolve 13 g of iodine in 100 mL of 20% (w/v) potassium iodide solution. Add three
drops of hydrochloric acid and dilute to 1000 mL with water.
Standardization – Dissolve, accurately, about 0.15 g of arsenic trioxide in 20 mL of M sodium
hydroxide. Heat if necessary. Add 40 mL of water, two drops of methyl orange and hydrochloric acid
until the color turns pink. Add 50 mL of 4% (w/v) sodium carbonate, 3 mL of starch TS and titrate
with 0.05 M iodine VS until permanent blue color. Each mL of 0.05 M iodine VS is equivalent to
4.946 mg of arsenic trioxide.
Conservation – In tightly closed glass container protected from light.
0.1 M iodine VS
Preparation – Dissolve approximately 13 g of iodine in 100 mL of potassium iodide at 36% (w/v).
Add three drops of hydrochloric acid and complete the volume to 1000 mL with water.
Standardization – Weigh, accurately, about 150 g of arsenic trioxide. Dissolve in 20 mL of M, sodium
hydroxide heating if necessary. Add 40 mL of water, two drops of methyl orange S1 and hydrochloric
acid diluted until the color turns pink. Add 50 mL of 4% (w/v) sodium carbonate and 3 mL of starch
TS. Titrate with the iodine solution, from the burette, until permanent blue color. Calculate the
molarity. Each 4.946 mg of arsenic trioxide is equivalent to 1 mL of 0.1 M iodine. Conservation –
Tightly closed glass containers.
Storage – Protect from light.
Preparation – Cool in ice bath 150 mL of methyl alcohol, in a 1000 mL volumetric flask. Add, in
small portions, approximately 2.5 g of recently fragmented metallic sodium. After the metal
dissolution, add toluene until 1000 mL and homogenize. Keep this solution in a container protected
from carbon dioxide.
Standardization – Weigh, accurately, about 400 mg of benzoic acid, dissolve in 80 mL of
dimethylformamide, add three drops of 1% (w/v) thymol blue solution in dimethylformamide and
titrate with the sodium methoxide solution until a blue color appears. Each 12.212 mg of benzoic acid
is equivalent to 1 mL of 0.1 M sodium methoxide.
nitrate solution. Calculate the molarity. Each mL of 0.1 M silver nitrate VS is equivalent to 5.844 mg
of sodium chloride.
Conservation – In tightly closed containers.
Storage – Protect from light.
stand for 10 minutes in the dark. Titrate the iodine released with the sodium thiosulfate solution until
having a yellow-green color. Add 3 mL of starch TS and continue with the titration until the blue
color disappears. Calculate the molarity. Each ml of 0.1 M sodium thiosulfate VS is equivalent to
4.903 mg of potassium dichromate.
Conservation – In tightly closed containers.
Additional information – Check the titer frequently.
7.4 BUFFERS
Certain pharmacopoeia assays require the adjustment or maintenance of pH. For such, they use
solutions named buffers, capable of withstanding variations in the activity of hydrogen ions. The
components used for preparing buffer solutions are described on the item Reagents. Components of
crystalline nature must be desiccated in advance in an oven between 110 °C and 120 °C, for one hour.
For the preparation of buffer solutions, use carbon dioxide-free water. They must be stored in
hermetic and appropriate containers. Consider the stability in the preparation of amounts for
consumption. The solutions are listed in increasing order of pH values. Other buffers with particular
characteristics are described on the texts from the respective assays.
Preparation – Mix 250 mL of 0.2 M monobasic potassium phosphate and 175 mL of 0.2 M sodium
hydroxide. Complete the volume to 1000 mL. Homogenize. Adjust pH to 7.1, if necessary.
Preparation – Dissolve 5.12 g of sodium chloride, 3.03 g of tromethamine and 1.40 g of sodium
iodide in 250 mL of water. Adjust pH to 8.4 with hydrochloric acid and complete the volume to
500 mL with water. Homogenize.
8 GENERAL INFORMATION
7B
The D value, decimal reduction time, is the time in minutes necessary for reducing the microbial
population by 90%, or 1 log cycle, at a specific condition, that is, to a surviving fraction of 1/10.
Therefore, where the D value of a biological indicator preparation from, for example, Geobacillus
stearothermophilus spores is 1.5 minutes under the total process parameters, that is, at 121 °C, if
treated for 12 minutes under the same conditions, it is possible to state that the lethality input is 8 D.
Applying this input to product sterilization depends on the initial microbial burden. Assuming that
the product’s microbial burden presents resistance to the sterilization process equal to the biological
indicator resistance and that the product’s initial burden is 102 microorganisms, the lethality input of
2 D would reduce the microbial burden to 1 (theoretically 100) and, consequently, additional 6 D
would result in a microbial survivor probability calculated as 10 -6. Under the same conditions, a
lethality input of 12 D can be employed as a typical approach to obtain overkill. Usually, the microbial
burden survival probability in the material, which sterilization validation process is being executed,
is not the same as the biological indicator. For valid use, therefore, it is essential that the biological
indicator resistance is higher than the bioburden of the material to be sterilized, being necessary to
assume the worst case scenario during the validation. The D value of the biological indicator to be
used must be determined or verified for each validation program, and also in case such program is
changed.
The determination of survivor curves, or fractional cycle approach, can be used to determine the D
value of the biological indicator selected for the specific sterilization process. This approach can also
be used to assess the product bioburden resistance. Fractional cycles are used to assess the reduction
in microbial count or achieve negative fraction. These numbers can be used both to determine the
process lethality under production conditions and to establish appropriate sterilization cycles. An
adequate biological indicator, such as the Geobacillus stearothermophilus preparation, must also be
used during routine sterilization. Any microbial burden method used for sterility assurance requires
adequate surveillance of the item’s microbial resistance to detect any changes.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.1-00
METHODS OF STERILIZATION
With a method of sterilization, the purpose is to remove, or destroy, all forms of life, animal or
vegetable, macroscopic or microscopic, saprophytic or not, from the product considered, without
assuring the inactivation of cell toxins and enzymes. The procedure selected to achieve the sterility
assurance level depends on knowledge of the nature of the material to be sterilized; the sterilization
process to be employed; and changes that may occur in the material, due to sterilization. The
knowledge on the type, amount and source of contaminants in the products, before sterilization, and
the employment of methods to minimize such contamination and prevent it after processing contribute
to ensure a successful sterilization.
This chapter reports concepts and principles involved in quality assurance and control for products
that must meet the sterility requirement and includes descriptions of the sterilization methods and
instructions for an aseptic process.
PHYSICAL METHODS
STERILIZATION BY HEAT
Heat is the simplest, most economic and safer sterilizing agent available. However, the sensitivity of
different microorganisms to action from heat is highly varied, with the spored forms being the most
resistant. The efficiency in the inactivation of microorganisms depends on temperature, exposure time
and presence of water, because lower exposure times and temperatures are required in presence of
water. Sterilization by moist heat causes coagulation of cell proteins from microorganisms, while
sterilization by dry heat occurs due to oxidizing processes, which need high temperature and long
exposure time.
Moist heat
The sterilization process employing saturated vapor under pressure is executed in a chamber called
autoclave. The basic operation principle is replacing air in the chamber with saturated vapor. To
displace air more efficiently in the chamber and inside the products, the sterilization cycle may
include air and vapor evacuation steps. For this sterilization method, the reference condition for
sterilization of aqueous preparations is of heating at no less than 121 °C for at least 15 minutes.
Different time and temperature combinations may be used, provided that validated and that they
demonstrate the effectiveness of the process selected, offering adequate and reproducible lethality
level when operated, as routine, within the tolerances established. Procedures and precautions are
applied to achieve a sterility safety level of 10−6 or better. Time and temperature combinations must
be established based on factors such as nature of the material and its thermolability, penetrability of
vapor in the product to be sterilized, and other parameters defined in the validation process. When a
sterilization temperature different from 121 °C is used, the concept of F0 must be used. F0 in a
particular temperature different from 121 °C is the time in minutes necessary to provide lethality
equivalent to the one provided at 121 °C for a certain time. F0 is a measure of sterilizing effectiveness,
that is, the number of minutes of thermal sterilization by steam at a given temperature supplied to a
container or product unit, at a given Z value.
To assure the sterilization process efficiency, the burden must be distributed in the chamber to allow
contact of vapor with regions of most difficult access. For materials sterilized by moist heat, it is
acceptable that a microbial survivor probability of 10-6 is achieved. For heat-stable products, the
necessary time to achieve the previous condition may be exceeded, resulting in overkill, which does
not apply to products that may undergo change due to excessive exposure to heat. In this situation,
the development of the sterilization cycle depends, especially, on knowing the microbial burden in
the product, which must be determined in a substantial amount of product batches, before sterilization.
The D value of the adequate biological indicator used, such as Geobacillus stearothermophilus, must
be assessed in the validation program or if there is any change to this program.
Dry heat
Thermal sterilization by dry heat is carried out in an oven with homogeneous heat distribution, which
can be achieved by forced air circulation. Items such as glassware, metals, powders, petrolatum, fats,
waxes, oily solutions and suspensions and special fabrics can be sterilized. This process is applied
especially to materials sensitive to sterilization by moist heat. For this sterilization method, the
reference condition is a minimum temperature of 160 °C for, at least, two hours. Different time and
temperature combinations may be used, provided that validated and that they demonstrate the
effectiveness of the process selected, offering adequate and reproducible lethality level when operated
as routine within the tolerances established.
A sterility assurance level of 10-12 is considered acceptable for heat-stable products. An example of
biological indicator to validate and monitor the sterilization by dry heat is the Bacillus atrophaeus
spore preparation.
The process employing dry heat can also be used for sterilization and depyrogenation as integral part
of the aseptic filling process, which requires very high temperatures due to the lower time of exposure
to heat. In continuous processes, it is usually necessary to have a cooling stage previous to the
packaging process. Due to the lower material dwell time, the validation program must include
parameters such as uniformity of temperature and dwell time.
Dry heat at temperatures higher than 220 °C can be used to sterilize and depyrogenate glassware. In
this case, a challenge with bacterial endotoxin must be part of the validation program, demonstrating
a reduction of no less than three log cycles of heat-resistant endotoxin, that is, test materials inoculated
with at least 1000 units of bacterial endotoxin. The test, with Limulus lysate, can be used to
demonstrate that the endotoxin was inactivated to no more than 1/1000 of the original amount, and
the remaining endotoxin is measured to ensure the reduction of 3 log cycles.
Ionizing radiations are high energy emissions, in the form of electromagnetic waves or particles that,
when colliding with atoms from the irradiated material, change their electric charge by electron
displacement, turning the irradiated atoms into positive or negative ions. When these radiations cross
the cells, they create free hydrogen, hydroxyl radicals and some peroxides, which in turn may cause
different intracellular injuries. The main sources of radiation are: alpha; beta; gamma rays and X rays.
The two types of ionizing radiation employed are radioisotope decay (gamma radiation) and radiation
by electron beam. The products are exposed to ionizing radiation in the form of gamma radiation
from an adequate source of radioisotopes (cobalt 60, for example) or a beam of electrons energized
through an electron accelerator.
In addition to the possibility of processing at low temperatures, which allows the sterilization of heat-
sensitive products, the sterilization by ionizing radiation has advantages such as low chemical
reactivity and the fact that there are few parameters to be controlled, being mandatory to control the
radiation dose absorbed. The dose of radiation established for sterilization must assure the materials
to be sterilized are not compromised. For gamma radiation, the process validation includes
establishing the compatibility of the material, establishing the product loading model and mapping
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.1-00
the dose in the sterilization container, identifying zones for maximum and minimum radiation doses,
defining the exposure time, and proving the application of the sterilization dose required. For
irradiation by electron beams, voltage, current, conveyor speed and the electron beam scanning
dimension must also be controlled. For this sterilization process, the absorbed reference dose is 25
kGy, but in some situations there is the need for selecting a higher or lower dose. The dose selected
must offer an adequate and reproducible level of lethality when the process is operated as routine
within the tolerances established. Procedures and precautions must be applied to achieve a sterility
safety level of 10−6 or better.
To validate the effectiveness of this sterilization, especially when lower doses are used, it is necessary
to determine the resistance to radiation of the product’s microbial burden. Specific product loading
patterns and the distribution of minimum and maximum doses absorbed must be established. The
doses absorbed are usually measured through specific dosimeters, such as standardized plastic support
that shows the color intensity proportional to the amount of radiation absorbed. The fractional cycle
approach provides the data used to determine the D10 value of the biological indicator, an information
applied to extrapolate the amount of radiation absorbed, to establish an adequate microbial survivor
probability. Currently, the dose is based on the resistance to radiation of the natural heterogeneous
microbial burden in the product to be sterilized. The validation procedures can be used the exposure
of the inoculated product, using resistant organisms, such as Bacillus pumilus, or exposure of samples
of the finished product from the production line to the sublethal process dose.
The procedure for selecting the radiation dose, based on the assessment of the resistance of
microorganisms that are constituents of the microbial burden of the product to be sterilized, allows a
more representative determination of its resistance when working with different susceptibilities to
radiation. This procedure requires enumerating the microbial population in a representative sampling
of different product batches. With knowledge on the microbial burden, the radiation dose is
established based on a table available on literature. Another method that allows establishing the
radiation dose is based on employing radiation dose increases until obtaining, at maximum, a positive
sample in 100 units irradiated. This information provides the base for extrapolating this dose and
obtaining the radiation dose. Periodic assessments must be made to ensure that the values established
remain effective (reference: ISO 11137-1: 2006 – Sterilization of health care products – Radiation –
Part 1: Requirements for development, validation and routine control of a sterilization process for
medical devices).
The effectiveness of the sterilization cycle must be assessed, periodically, by determining the
product’s microbial burden, or by employing the biological indicator and using calibrated dosimeters.
STERILIZATION BY FILTRATION
The filtration is employed for sterilization of heat-sensitive solutions through physical removal of
contaminant microorganisms. The filtering material cannot shed fibers or extractable materials that
are undesirable for the filtered solution, which restricts the nature of the filtering element to glass,
metal, synthesized polymers and polymeric membranes.
A filter assembly consists of a porous matrix inserted in an impermeable housing. The effectiveness
of a filtering medium or substrate depends on the material pore size, the adsorption of microorganisms
on or in the filter matrix, and the sieving or exclusion mechanism. The effect of exclusion by size is
a function of the pore opening (diameter), and the adsorption depends on the composition, thickness
of the filtering element and fluid being filtered.
The pore size of filtering membranes is estimated by a nominal value that reflects the filter membrane
capacity of retaining microorganisms represented by specific strains. The filtration for sterilization
purposes is usually conducted with graduation membranes of nominal pore size of 0.2 mm or smaller.
Such sterilizing filtration membranes, classified as 0.22 mm or 0.2 mm, depending on the
manufacturer, are capable of retaining 100% of a culture with 107 microorganisms of Brevundimonas
diminuta (ATCC 19146), per cm2 of filtering membrane surface, under minimum pressure of 30 psi
(2.0 bar).
The user is responsible for selecting the filter due to the nature of the material to be filtered, which
meets the needs from the sterilization process, and must also determine whether the parameters
employed in the production will influence the effectiveness of microbial retention. Since the filtration
process effectiveness is also influenced by the bioburden of the solution to be filtered, it is important
to determine the microbial quality of the solutions before the filtration, as well as establish parameters
such as pressure, flow rate and characteristics of the filtering unit.
The log reduction value can also be used to assess the retention capacity of the filtering membrane.
For example, a 0.2 mm filter, which can retain 107 microorganisms from a specific strain, will have
a minimum log reduction value of 7, under the conditions stated.
The filtration system must be tested before and after the filtration process to ensure its integrity is
maintained during the filtration process. Typical use tests include bubble point test, diffusive airflow
test, pressure hold test, and progressive flow test. The bubble point test consists of a non-destructive
test, and derives its name from viewing bubbles after applying a certain pressure on the filter. For
example, after filtration of approximately two liters of sterile distilled water, constant nitrogen
pressure is applied for five minutes for 0.2 mm cellulose ester membranes. For each type of filter
there is a limit pressure value to be supported, without presenting the formation of bubbles, indicating
the resistance of the filtering material. The tests must be correlated to the retention of microorganisms.
Additional tests conducted by the filter manufacturer, such as the microbial challenge test, are not
usually repeated by the user.
CHEMICAL METHOD
STERILIZATION BY ETHYLENE OXIDE GAS
Gas sterilization can be the method selected for materials that do not resist high temperatures, such
as in the processing by dry heat or moist heat. The active agent generally employed in gas sterilization
is ethylene oxide. Among the disadvantages of this sterilizing agent, there are its mutagenic
properties, the possibility of toxic residues in the materials treated and its highly flammable nature,
except when in certain mixtures with inert gases. The sterilization process is usually conducted in a
pressurized chamber with design similar to autoclave, but with specific characteristics, such as system
for degassing after sterilization and minimization of exposure from operators to gas.
The qualification program for the process of sterilization with ethylene oxide is broader than for other
sterilization processes, since humidity, vacuum/positive pressure and concentration of ethylene oxide,
as well as temperature, must be controlled. It is important to determine and demonstrate that all critical
process parameters are adequate inside the sterilization chamber throughout the cycle. Since the
sterilization parameters applied to the products to be processed are critical, it is recommendable to
precondition the load to minimize the time of exposure to the temperature required.
The validation program is usually conducted by employing the inoculated product, or simulate
inoculated product, with appropriate preparations, such as Bacillus atrophaeus spores. Biological
indicators are usually employed to establish the final microbial survivor probability, using the
fractional cycle concept, to design a cycle of sterilization with ethylene oxide, and they must be used
in product, or simulated product, loads with full chamber.
The biological indicator must be employed in routine cycle monitoring, and also in the planning of
the cycle of sterilization by ethylene oxide. Another important aspect of the sterilization process
planning is the definition of the type of packaging of the material to be processed and its distribution
in the sterilization chamber, due to the limited capacity of diffusion of ethylene oxide in the innermost
areas of the product.
The control of residues in products sterilized by ethylene gas is necessary to ensure minimum risk for
the patient when using the product. Residual levels of ethylene oxide (EO), ethylene chlorohydrin
(ECH) and ethylene glycol (EG) must be followed to minimize the exposure by professionals and
patients.
The maximum residues admissible for EO and ECH are presented. Local effects, such as irritation,
are considered as incorporated to the tolerable contact limit (TCL). No limit is defined for EG,
because the risk assessment available indicates that the admissible levels calculated are higher than
the residual levels that can be found in the products.
The protection against systemic effects was considered on the limits described. The residual level of
EO is considered at the moment of product release.
To establish the maximum daily doses of EO and ECH, the products must be classified according to
the duration of contact with the patient:
Limited exposure
Prolonged exposure
Products with one-time, multiple or repeated use or cumulative contact of long duration – from 24
hours to 30 days;
Permanent contact
Products with one-time, multiple or repeated use or cumulative contact of long duration – above 30
days.
“Multiple use” means the repeated use of the same type of product, such as, for example, dialysis
cartridges.
If a product is classified in more than one duration category, the stricter considerations from test
and/or assessment must be enforced. For multiple exposures, the classification must take into account
the potential cumulative effect, considering the time period when these exposures occur.
The limits for permanent contact and prolonged exposure products are expressed as maximum
average daily doses. If there are data available, one must consider the proportional reduction of limits
if multiple products are used at once, or the proportional increase of limits when the product is used
only in part of the exposure period.
For permanent contact products, the average daily dose of EO is no more than 0.1 mg. The maximum
dose of EO is 4 mg on the first 24 hours; 60 mg on the first 30 days; and 2.5 g through the lifetime.
The average daily dose of ECH is no more than 0.4 mg. The maximum dose of ECH is 9 mg on the
first 24 hours; 60 mg on the first 30 days; and 10 g through the lifetime.
For prolonged exposure products, the average daily dose of EO is no more than 2 mg. The maximum
dose of EO is 4 mg on the first 24 hours and 60 mg on the first 30 days. The average daily dose of
ECH is no more than 2 mg/day. The maximum dose of ECH is 9 mg on the first 24 hours and 60 mg
on the first 30 days.
For limited exposure products, the average daily dose of EO is no more than 4 mg, and the average
daily dose of ECH is no more than 9 mg.
The tolerable contact limit (TCL) is established to prevent localized irritation due to the release of
EO or ECH by the product, being expressed in micrograms per square centimeter (μg/cm2) for EO
and in milligrams per square centimeter (mg/cm2) for ECH, where the square centimeter unit
represents the surface area of the product interface with the patient.
For implants and contact products, the TCL of EO is no more than 10 µg/cm2 or negligible irritation.
The TCL of ECH is no more than 5 mg/cm2 or negligible irritation.
The norm ISO 10993-7 describes the acceptable limits for special situations, such as intraocular
lenses; blood cell separators, used in blood collection; blood oxygenators and separators; products
used in cardiopulmonary bypass procedures; blood purification devices, extracorporeal devices and
gauze bandages.
The procedure for determining the compliance with limits consists of extracting the residue from
samples, determining the product contact surface, analyzing and interpreting data.
A validated extraction and measurement method must be used to determine the residual levels of EO
and ECH in the product. Many analytical methods have been investigated and the broad variety of
materials and formats of sterile products may eventually present issues in determining residues.
Therefore, any analytical method must be validated before use.
When residues are within the requirements for the products tested by exhaustive extraction, there is
no need to test the product by extraction of simulated use, provided that the results are below the
limits specified. When exhaustive extraction is used, attention must be given to the limits for the first
24 hours and for the first 30 days. Small products must be extracted in an adequate container. When
a product is too large to be entirely extracted, it may be necessary to extract many representative
portions of the product components to ensure the reliability of derived data.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.1-00
Many factors influence the initial levels of residues and their dissipation rate, and precautions must
be taken, such as the moment of taking the sample from the sterilized load; transportation to the
laboratory; effects of laboratory conditions on the aeration rate, as well as the safety of the analyst
and the operator. The samples must remain with the product load until the day of analysis, or until
the test samples are taken and frozen immediately. The samples must be sealed, shipped in dry ice
and stored by freezing until their analysis. The test samples can also be taken directly from the product
load in the desired aeration range and immediately placed in a confined space (headspace) vial, sealed
and sent to the laboratory for analysis. Alternatively, the samples can be extracted and the extraction
fluid, sent for analysis. If the extraction fluid is water, the shipment must be made so that the liquid
is maintained at low temperatures (<10 °C) until it arrives to the laboratory. The test must be
conducted to measure the hydrolysis of EO into EG.
The samples must be placed in a fume hood, removed from the package, prepared according to the
instructions of use from the product, and the extractions must be started soon after removal from the
package or conclusion of the pre-use preparations.
A sample blank must be tested to check for the presence of interferences. The blank must be prepared
by using a non-sterilized sample submitted to the same procedure applied to test samples. The
chromatographic conditions must be modified to separate the interference peak from the analyte peak,
or an alternative analytical procedure may be used when the retention times are conflicting or
overlapped.
The nature and size of the product sample will be considered to establish the ideal volume of fluid for
extraction, and the sample/extraction fluid ratios must not compromise the detection sensitivity. To
maximize the analytical sensitivity, a minimum amount of extraction fluid must be used, and products
with highly absorbing materials may require increased sample/extraction fluid ratios.
Two methods for basic extraction are used for determining EO residues: simulated use extraction and
exhaustive extraction. The method selected must be adequate to the product use and examples can be
seen on the norm ISO 10993-7.
Temperatures and extraction times must be determined based on the nature of patient exposure and
duration of contact with the product. The norm ISO 10993-12 is a reference for extraction
temperatures.
For certain products, the simulated use extraction may result in relatively large elution volumes, and
may considerably increase the limit of detection for the residual material, compromising the
determination of compliance. In very large products, the extraction of representative portions can be
used to ensure data reliability.
Simulated use aqueous extraction is the method of reference, because it is the only method that
produces results directly comparable with the limits specified.
Water, normally used for recovery of EO and ECH residues in simulated use extractions, is employed
for elution of EO residues from the sample, not to dissolve the sample. In the case of packaging use
simulation, the product must be filled to eliminate air bubbles, at 37 °C, for products in total or partial
contact with the body during the use (body temperature) and at 25 °C for products with no immediate
contact with the body during their use (room temperature). If the test is not executed immediately,
the extract must be taken from the sample and sealed in a poly-tetrafluoroethylene coated vial. The
standard solution or extract vial headspace must be inferior to 10% of the total volume. The extract
can be stored in the refrigerator for several days. It is necessary to use caution when employing water,
since EO can be converted to EG and/or ECH during the extraction period, as well as during the
extract storage.
The amounts of EO or ECH extracted through normal product use simulation are not necessarily equal
to the total residual content of the product.
Exhaustive extraction methods are targeted at recovering the entire residual content of product, being
an acceptable alternative in certain situations.
A variety of extraction fluids can be used for exhaustive recovery of residual EO, and its selection
depends on the composition of the product material and its components.
The norm ISO 10993-7 is a detailed guide on assessment of residues from sterilization by EO and
indicates how to convert the concentration of residue observed in extracts for the amount administered
to a patient, in milligrams.
If sufficient experimental data on the kinetic of residue diffusion are available, it may be possible to
group products for tests based on similarity of materials, manufacturing processes and use.
Dissipation curves may be used to estimate the post-sterilization time required for the products or
families of similar products, to reach the limits of residues, especially for EO. The products must be
released according to the post-sterilization times and conditions, pre-determined and defined by
experimental dissipation curves, so that the target levels of EO residues for the product are assured.
Concerns with product aeration must be considered by gathering sterilization load data collected from
the quarantine storage or aeration in different times of the year, if the aeration temperatures are
different.
The product re-sterilization and the presence of other products sterilized with EO in adjacent areas
must also be considered when obtaining experimental data to generate such dissipation curves.
When dissipation curve data are not available, the product can be released if the data are obtained
from tests conducted according to the procedures and the limits described for EO and, if applicable,
for ECH are met.
The product is compliant when it complies with the limits described for EO and, if applicable, for
ECH.
The products manufactured and sterilized in controlled conditions may be cleared considering data
from at least three sterilization batches at different times.
Once the process is validated, it must be revalidated periodically, and after changes in product,
equipment and process that may compromise the sterility assurance level specified.
The main validation elements are: installation qualification; operation qualification; and performance
qualification.
INSTALLATION QUALIFICATION
The execution of the plan for installation qualification must offer documented evidence that the
equipment and all auxiliary items were provided, installed and operate according to specifications. It
must be demonstrated that the sterilization equipment, its components, auxiliary items and supplies,
such as vapor, water and air, have been correctly designed, installed and calibrated.
In order to meet the parameters and limits recommended for sterilization, it is necessary to use
appropriate instrumentation to monitor and control critical parameters such as temperature, time,
humidity, concentration of sterilizing gas, or radiation absorbed. These instruments must be assessed
in the installation qualification.
The installation qualification comprises the following elements: equipment, installation and function.
Concerning equipment and installation, the specifications of the sterilizer; auxiliary items and
services; operating procedures; the location of the facility and the documentation must be defined in
advance and verified in the installation qualification, ensuring its compliance. To ensure the function,
it is necessary to verify that the equipment and operating safety systems work according to their
specifications; that the operation cycles are as defined; and that there is no evidence of leakage of
utilities or in the sterilizer, when applicable.
In the documented procedures for installation qualification, it must be specified how each
qualification element is planned, executed and reviewed. The documentation that provides support to
the installation qualification includes description of physical and operational characteristics of the
equipment; its components and services. Designs and process and instrumentation diagrams must be
verified against the setup proposed and updated, when necessary. Safety systems applicable must be
assessed to ensure the performance, quality and safety of equipment and operators.
The installation qualification is necessary for new equipment or when the existing sterilizer is
replaced or relocated. The qualification must be redone at defined time intervals, and at least partially
when there are changes that may change the sterilization process effectiveness, such as replacement
or overhaul of equipment, or parts, modifications in process supplies, and change to radioactive
source.
OPERATIONAL QUALIFICATION
In the operational qualification, it is necessary to demonstrate that the equipment installed is capable
of conducting the sterilization process specified within the intervals defined. The interval of
parameters and the limits of operation must be established in the process definition. Before the
operational qualification, the calibration status for the entire instrumentation used to monitor, control,
indicate and register must be confirmed.
For autoclaves and other sterilizers that employ thermal process, studies on heat distribution in
different positions must be conducted considering the chamber size and the load. It is necessary to
confirm that the chamber (empty and full) operates within the critical parameters in all its main
locations. The number and position of thermocouples are determined by the load type and
configuration; equipment size; type of instrument; and cycle employed. An acceptable temperature
range in the empty chamber is ± 1 °C when the chamber temperature is 121 °C. For ethylene oxide
sterilizers, relative humidity, concentration of gas and temperature must be monitored by sensors
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.1-00
distributed in adequate positions. Applicable safety systems must be tested. Control software must be
validated and challenged in fault conditions. The penetration and distribution of ionizing radiation on
the load must be performed and monitored by dosimeters. The operation for qualification of sterilizing
filters is conducted through filter integrity test, differential pressure measurements, and flow rate.
Since fluids sterilized by filtering membranes can be exposed to the environment during the following
processing, the environmental control and the qualification and/or validation of the aseptic handling
area must be an integral part of the process of sterilization by filtration.
PERFORMANCE QUALIFICATION
In the performance qualification it is necessary to demonstrate that the sterilization process is capable
of repeatedly reaching the sterility assurance level pre-determined for defined product loads; that the
apparatus works consistently according to pre-determined criteria; and that the product meets the
specified safety, quality and performance requirements.
The performance qualification comprises physical and microbiological assessments that demonstrate
the effectiveness and reproducibility of the sterilization process, maintaining the product
characteristics specified.
In physical studies, it is necessary to consider: criteria such as test load representative of the process;
package identical to the product; pre-conditioning; temperature profile and temperature on the point
of reference; response from chemical indicators; package integrity; documentation; among others.
The load for sterilization must be established and documented, taking into account parameters such
as configuration, distribution, orientation, density, dimension, composition of material, use and type
of pallets. The product or material with similar characteristics to the product (simulated product) used
for qualification must have a package identical to the product and represent, as a minimum, the worst
case of production routine load, that is, the most difficult configuration to sterilize. Criteria for
reutilization of load must be defined, and it must be equilibrated with the environmental conditions
or aerated before reuse. With the data generated, it is necessary to demonstrate the compliance with
physical and chemical parameters applicable. The relation between the conditions of monitoring
positions during the qualification and the routine must be established.
The performance qualification must be repeated when significant changes are proposed, such as
changes in product design and package, load configuration or density, and sterilization equipment or
process. The effects of these changes in the stages of validation of the sterilization process must be
assessed.
The documented review of the validation data generated in the installation, operation and performance
qualifications must be conducted to confirm the acceptability of the sterilization process and define
the process specification, including parameters and tolerance.
The final stage of the validation program requires the documentation of support data developed in the
execution of this program.
BIOLOGICAL INDICATORS
The biological indicator is defined as a preparation characterized by a specific microorganism that
provides defined and stable resistance to a certain sterilization process. Spore-forming bacteria are
microorganisms recognized as appropriate for use as biological indicators, since, except for ionizing
radiation, these microorganisms are significantly more resistant to sterilization processes than
microorganisms from the natural microbial burden of the product.
A biological indicator can be used in the performance qualification for the sterilization equipment
and in the development and establishment of the sterilization process for a specific product. Biological
indicators are used in processes for obtaining the sterile product in its final container and in
sterilization of equipment, materials and components of the package, employed in the aseptic process.
Biological indicators can also be used to monitor sterilization cycles in periodic revalidations and to
assess the capacity of the process used in decontamination of isolators or clean rooms.
There are at least three types of biological indicators, and each type incorporates a microbial species
with known resistance to the sterilization process.
One type of biological indicator includes spores that are added to a support or carrier (disc or strip
in filter paper, glass, plastic or another material) packaged in order to maintain the integrity and
viability of the material inoculated. Carriers and primary packaging must not have any type of
chemical, physical or microbiological contamination that may compromise the performance and
stability of the biological indicator and cannot undergo change due to the sterilization process
submitted. Carriers and primary packaging must withstand transport and handling until the moment
of use and must avoid loss of the original inoculum during the transportation, handling and storage
until the expiration of the validity period.
Another type of biological indicator consists of a spore suspension inoculated in representative units
of the product to be sterilized. When it is not possible to employ the actual product, it is possible to
inoculate a simulated product, which differs from the actual product in some characteristics, but
behaves in a similar manner when submitted to test or sterilization conditions. A spore suspension
with known D value must be used for inoculation of the actual or simulated product, ensuring that the
simulated product does not compromise the resistance of the biological indicator when used. The
physical design of the (actual or simulated) product to be inoculated may affect the resistance of the
microbial suspension inoculated. In case of liquid products, it is recommendable to determine the D
value and the Z value of the biological indicator in the liquid product specified. The population, D
value, Z value where applicable and microorganism destruction time must be determined. Z value is
the temperature rise, in degrees, necessary to reduce the D value by 90% or to produce a reduction of
a log cycle in the thermal resistance curve.
The third type is the self-contained indicator, presented in such a way that the primary packaging
targeted at incubation after sterilization has the growth medium required for the microorganism
recovery In this case, the system comprised of the biological indicator and the microorganism growth
medium must be resistant to the sterilization process and must allow the penetration of sterilizing
agent. The D value, microorganism destruction time and survivor time must be determined for the
system, not only for the paper strip or disk that contains the microorganisms. After sterilization, the
contact of strips or disks with microorganisms and the culture medium is permitted.
The self-contained biological indicator may consist of a spore suspension in a culture medium with
pH indicator that allows view the presence or absence of growth after the incubation. The self-
contained system resistance depends on the penetration of the sterilizing agent in the package, which
must be controlled by the manufacturer through the design and composition of the material that
comprises the package, ampoule or container. The self-contained indicator in the form of ampoule
may be incubated directly after exposure to the sterilization process, in the conditions specified. The
absence or presence of microbial growth is determined visually, from the change of color of an
indicator incorporated to the medium, by the turbidity resulting from the development of the
microorganism, or also by microscopic examination of the inoculated medium. The self-contained
biological indicator must withstand the transport and handling during the use without any ruptures or
loss of the original inoculum. During or after the sterilization process, the material of which the self-
contained system is comprised must not retain or release any substance that may inhibit the growth
of surviving microorganisms. The growth promoting capacity of the culture medium after exposure
to the sterilization process must be proven.
All operations involved in the preparation of biological indicators must be monitored through a
documented quality system that allows traceability of all materials and components incorporated to
the microbial suspension, the inoculated carrier or the biological indicator. The preparation of stock
spore suspensions of the microorganisms selected as biological indicators requires the development
of appropriate procedures, including cultivation, harvesting, purification and maintenance. The stock
suspensions must predominantly have dormant (non-germinative) spores maintained in non-nutritive
liquid. The final product provided by manufacturers (microbial suspension, inoculated carrier or
biological indicator) must not contain a microorganism different from the test microorganism in
sufficient number that may affect the product. To minimize the presence of microorganisms different
from the test microorganism, the system must be validated, monitored and registered.
The selection of the biological indicator requires knowledge of its resistance to the specific
sterilization process to ensure that the biological indicator system provides a higher challenge than
the product microbial burden system.
The efficient use of biological indicator for development of the cycle, process and validation, or for
monitoring the routine sterilization process, requires knowledge on the material to be sterilized,
including its components and packaging material. Only biological indicators recognized and specified
on monographs must be used in the development or validation of a sterilization process, to ensure
that the biological indicator selected offers a greater challenge to the sterilization process than the
microbial burden in the product.
In case of using biological indicators with different characteristics from the ones commercially
available, it is possible to cultivate microorganisms described in scientific literature to prepare
biological indicators. The user must be capable of determining the D and Z values for in-house
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.1-00
indicators. When a non-commercial biological indicator is used, the population, purity and validity
must be confirmed to ensure the legitimacy of the tests to be performed using this indicator.
When the sterilization process definition is based on the product microbial burden, it must be
quantified and the resistances of the biological indicator and the microbial burden must be compared.
The sterilization process must result in a minimum sterility assurance level of 10-6.
The overkill method may be employed in the development of the sterilization process and, in this
case, specific considerations related to the supposed resistance used in establishing the process
lethality requirements must be made. In general, overkill processes are developed with the assumption
that the microbial burden is equal to 106 highly resistant microorganisms. A 12 D process is defined
as the process that provides sufficient lethality for reduction of 12 log cycles, equivalent to 12 times
the D value for microorganisms with resistance above the average resistance from microorganisms
present in the product microbial burden. By assuming a microbial burden of 106, an overkill process
will result in a probability of non-sterility inferior to 10-6. The use of the overkill process and its
validation may minimize or avoid the need for quantification and identification of the product
microbial burden.
For the moist heat process, spores from appropriate strains of Geobacillus stearothermophilus are
commercially available as biological indicators. Other spore-forming microorganisms resistant to
moist heat, such as Clostridium sporogenes, Bacillus atrophaeus and Bacillus coagulans, can also be
used in the development and validation of a process of sterilization by moist heat.
For validation of the process of sterilization via dry heat, Bacillus atrophaeus spores can be employed.
During the validation, studies can be conducted for assessment of depyrogenation instead of microbial
inactivation, since the bacterial endotoxin inactivation rate is much slower than the inactivation of
Bacillus atrophaeus spores. In practice, a reduction of at least three log cycles of the endotoxin level
results in a non-sterility probability lower than 10-6.
To monitor sterilization processes employing ionizing radiation, Bacillus pumilus spores have been
used, despite this not being an usual practice. The method for establishing the radiation dose, more
employed, does not use biological indicators. Some microorganisms in the microbial burden of the
material to be sterilized may present higher resistance to the process of sterilization by radiation in
comparison with Bacillus pumilus spores.
For the process of ethylene oxide sterilization, spores from subspecies of Bacillus atrophaeus var.
niger are used, when 100% ethylene oxygen or different mixtures of gases are used.
PERFORMANCE EVALUATION
The manufacturer’s responsibilities are: determining and providing the performance characteristics
of the lot of biological indicator through certificate of analysis that confirms the validity of the
performance declared on the product package; definition of the sterilization process for which the
biological indicator is recommended; characterization of each type of biological indicator, using
standardized conditions and adequate equipment; D value and the method through which this value
was defined; microbial count; stability of resistance until the validity indicated on the label; storage
conditions, including temperature and relative humidity; guidance about the culture medium to be
employed; and the conditions for recovery of microorganisms after exposure to the sterilization
process and disposal.
COMMERCIAL PRODUCTS
When a biological indicator is commercially acquired, its suitability for use in a sterilization process
must have been established in studies, unless there are data available to confirm the employment of
the indicator in a specific process. The user must establish, in their institution, the acceptance criteria
for the lots of biological indicator. When a biological indicator is acquired, it must be accompanied
with a certificate issued for each lot. If the biological indicator is employed in a different manner than
the one indicated by the manufacturer, the user must proceed to the registration of conditions of use,
verifications and performance of the biological indicator.
After receiving a lot of biological indicator, the user must quantify the burden of spores per unit and
proceed to the verification of morphology and purity of microorganisms, confirming, as a minimum,
the genus of the microorganism. Information related to D value, to storage conditions, to validity
period and to stability of the biological indicator must be followed and registered. The user may
consider the need to audit the D value before accepting the lot of biological indicator. For long-term
storage, it is important to verify the D value and the stability of count. In case of spore suspension
storage for a period superior to 12 months, under documented conditions, the confirmation of count
and proof of resistance of the spores must be conducted, unless the performance from a previous
culture has been validated after a long storage period. The results from resistance assays and spore
count must be within the acceptance range established during the approval of the spore suspension
lot.
NON-COMMERCIAL PRODUCTS
The user may decide to cultivate microorganisms for development of biological indicators to be
employed in the development or validation of a sterilization process. If the user becomes a producer,
the biological indicator performance requirements must be met. If a biological indicator system is
employed for the development of a new sterilization process or validation of an existing process, the
same performance criteria for commercial products must be met.
for sporulation; changes occurred in the preparation of medium; observations about contamination of
suspension; data before and after the thermal shock; records of use of spore suspension and resistance
to sterilization (particularly D values and Z values, where applicable).
Regardless of the sterilization process to be employed, the initial production of microorganisms, their
resistance to the sterilizing process, and the product inoculation place may influence the biological
indicator inactivation rate. During the validation process, the biological indicator must be inoculated
in several product locations, ensuring the challenge both of the package and of the product stored in
it, to ensure a sterility assurance level of 10-6 for the product and for the package.
It may be necessary to determine, through laboratory studies, if the product components are more
difficult to sterilize than, for example, a solution or medicine included in it. The product performance
qualification phase must identify the most important parameters from the process for inactivation of
microorganisms in the locations most difficult to sterilize. The biological indicator survival is
consequence of the resistance and size of the microbial population. Therefore, not always a biological
indicator with population of 106 is necessary for confirming a sterility assurance level of 10 -6. The
appropriate use of biological indicators is to confirm that the parameters established in the sterilization
process ensure the sterility assurance level desired. In the sterilization by moist heat, the employment
of biological indicator confirms the lethality determined by physical parameters. Biological indicators
with relevant D value and populations substantially lower than 106 are adequate to validate many
sterilization and decontamination processes. It is important that the users are qualified to justify,
scientifically, the selection of a biological indicator.
ASEPTIC PROCESS
Although the terminal sterilization of a packaged product is the procedure that ensures minimum risks
of microbial contamination in the production of a lot, there are classes of products that cannot be
sterilized on their final packaging and that must be prepared employing an aseptic process. This
process is designed to prevent the contamination of sterile components by viable microorganisms or
even in the intermediate phase of production, when a component must be provided free from
microorganisms. A product defined as processed aseptically consists of components that were
sterilized by one of the sterilization processes, such as, for example, filtration, if it is a liquid. In the
case of packaging material made of glass, dry heat can be employed; when it is a polymeric packaging
material, such as lids, autoclave or ethylene oxide can be used.
In the aseptic process, the environment where the ingredients are handled and the aseptic filling step
are considered critical points. The requirement for a properly validated project that maintains the
necessary conditions for the aseptic process encompass an environment free from viable
microorganisms, where the air quality is ensured by suitable equipment, by personnel trained and
equipped according to the environment requirements and by operation to be performed. The desired
environment may be obtained through the air filtration technology that provides supply of air with
the microbial quality required. The plant planning must provide an airflow cascade system with higher
positive pressure, of the most critical (aseptic) areas for those of intermediate requirement
(preparation areas), and, finally, the ones with lower requirement of control; and must also allow
frequent air exchange, in addition to the employment of unidirectional airflow in the immediate
surroundings of the product or components exposed and the control of temperature and humidity
(when applicable). The installations must include primary (near the product) and secondary (where
the aseptic process is conducted) isolation systems through physical barriers. Surfaces such as walls
and ceiling must be smooth, allowing frequent sanitization. Changing rooms must have adequate
space for the personnel and storage of sterile clothing. The personnel training concerning apparel
must include the correct use of clothing, such as overalls, gloves and other items that provide body
surface coverage. The entire sanitization process must be documented. The certification and
validation of the process and aseptic installations are conducted through confirmation of efficiency
of the filtration systems; by the environment microbiological monitoring procedures; and by
simulation of the product aseptic filling, employing a sterile culture medium. The monitoring of the
aseptic installation must include the periodical examination of environmental filter, the routine
monitoring of particulate and viable material, and simulated filling with sterile culture medium.
Media fill is a test for simulating aseptic operations in which the product is replaced by a culture
medium and serves to ensure that the processes used are capable of leading to sterile products.
There are alternative methods to assess and control the microbiological status of clean rooms and
zones, with a variety of apparatuses and methods for microbiological sampling. The inadequate
application of sampling and microbiological analysis may cause significant variability and potential
for inadvertent contamination. A considerable number of sterile products is manufactured by aseptic
processing, which depends on the exclusion of microorganisms from the processing line and,
therefore, on the prevention of entry of microorganisms in open containers during the packaging, and
the packaging and microbial burden of the product and the manufacturing environment are important
factors related to the sterility assurance level of these products.
The classification of air cleanliness in clean rooms and zones, through analysis of concentration of
particles suspended on air, is ruled by the norm ABNT NBR ISO 14644-1 – Clean rooms and
associated controlled environments – Part 1: classification of air cleanliness. This document applies
to particles suspended on air inside a controlled environment, but does not intend to characterize the
viable or non-viable nature of particles.
The enforcement of this norm has been used by manufacturers of clean rooms and zones to guide the
construction, preparation and maintenance of these facilities. However, it does not provide a relation
between the number of non-viable particles and the concentration of viable microorganisms.
The pharmaceutical industry is concerned with the count of viable particles and, in the case of
injectable products, there is the additional concern with the count of total particles. The justification
that the smallest the number of particles present in a clean room, the less probable the presence of
microorganisms carried by air, is acceptable and directive in the design, construction and operation
of clean rooms and zones.
The Table 1 describes the air cleanliness classes according to the norm ABNT NBR ISO 14644-1,
which is based on limits of particles with sizes from 0.1 to 5 μm. The Table 2 presents a list of
different systems for classification of clean rooms.
It is acceptable that, if a smaller number of particles is present in the clean room or controlled
environment, the microbial count under operational conditions will be lower, provided there are no
changes in the airflow, temperature and humidity. Clean rooms are maintained under an operational
control status based on dynamic (operational) data.
Table 1 – Classes of air cleanliness for particles in suspension, selected for clean rooms and zones.
Maximum limits of concentration (particles/m3 of air) for particles equal to or
Classification number
larger than the sizes considered
(N) 0.1 µm 0.2 µm 0.3 µm 0.5 µm 1 µm 5 µm
ISO Class 1 10 2
ISO Class 2 100 24 10 4
ISO Class 3 1 000 237 102 35 8
ISO Class 4 10 000 2 370 1 020 352 83
ISO Class 5 100 000 23 700 10 200 3 520 832 29
ISO Class 6 1 000 000 237 000 102 000 35 200 8 320 293
ISO Class 7 352 000 83 200 2 930
ISO Class 8 3 520 000 832 000 29 300
ISO Class 9 35 200 000 8 320 000 293 000
Microbiological monitoring programs for clean rooms and zones must assess the effectiveness of
cleaning and disinfecting practices that may have impact on the microbial burden of the environment.
Usually, the microbiological monitoring does not identify and quantify all microbial contaminants in
the environments; however, the routine monitoring must provide sufficient information to ensure that
the environment is operating within the adequate control status.
The environmental microbiological monitoring and the data analysis conducted by qualified
personnel allow the control status to be maintained in clean rooms and zones. The environment must
be sampled during regular operations to allow significant data to be collected, and the microbial
sampling must occur when the materials are in the area, the processing activities are ongoing, and all
employees are working in the location.
The microbiological monitoring of clean rooms and zones must include the quantification of the
microbial content in the environment air; the compressed air that enters the critical area; surfaces;
devices; containers; floors; walls; and personnel clothing. The goal intended with the program is to
obtain representative estimates of the microbial burden of the environment, and once compiled and
analyzed any trends must be assessed by trained personnel. It is important to review environmental
results based on the frequency specified, as well as review results for prolonged periods to determined
whether there are trends. Trends can be viewed through statistic control boards, which include alert
levels and action. The microbiological control of controlled environments can also be evaluated based
on trend data. Periodic reports or summaries must be issued to alert the person responsible for the
area.
When the microbiological level specified for a controlled environment is exceeded, there must be
documentation review and investigation. The investigation must include the review on the area
maintenance documentation; the disinfection documentation; inherent physical or operational
parameters, such as changes in environment temperature and relative humidity; and the training phase
of the personnel involved. After the investigation, the actions adopted may include reinforced
personnel training to emphasize the microbiological control of the environment; additional sampling
in higher frequency; additional disinfection; additional product testing; the identification of microbial
contaminant and its possible source; and reevaluation and revalidation of current standardized
operating procedures, if necessary. Based on the review of the investigation and on test results, the
meaning of the exceeded microbiological level and the acceptability of operations or products
processed under such condition can be defined. Every investigation and justification of actions must
be documented and become part of the quality management system.
Clean room and zone are defined by certification according to the applicable rule, and the parameters
assessed include integrity of filters, pressure and speed differentials, patterns and changes of air. An
example of method for conducting the particle challenge test for the system consists of increasing the
concentration of particles in the environment through smoke around the critical work areas and view
the air displacements. The presence of vortices and turbulent zones can be viewed and the airflow
pattern can be fine-tuned to eliminate or minimize undesirable effects. This evaluation is made under
simulated production conditions, but with equipment and employees in the location.
The appropriate test and optimization of the physical characteristics of the clean room or controlled
environment are essential before concluding the microbiological monitoring program validation. The
assurance that the environment is operating properly and according to its specifications will give more
assurance that the microbial burden of the environment will be appropriate for aseptic processing.
These tests must be repeated during the routine certification of the clean room or zone and whenever
changes considered significant are made in the operation, such as changes in the flow of people,
processing, operation, material flow, air manipulation system or equipment layout.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.1-00
Here are some definitions of systems used to reduce the aseptic process contamination rate.
Barriers: device that restricts contact between operator and aseptic field. Barriers cannot be sterilized
and do not always have transfer systems that allow the passage of materials in and out of the system
without exposure to the surrounding environment. There are different types of barriers, from plastic
curtains in critical zones to hard barriers in devices, which may incorporate elements such as glove
support and transfer port.
Blow/Fill/Seal: this system combines the container assembly with the product packaging and sealing
in a single equipment. From the microbiological standpoint, the sequence of forming the container,
filling the sterile product and forming and applying the seal is obtained aseptically, in a seamless
operation with minimum exposure to the environment. These systems have existed for many years
and the contamination rates are lower than 0.1%.
Isolators: technology used for a dual purpose, to protect the product from contamination by the
environment and by people during filling and closure and to protect people from toxic or harmful
products during the production. This technology is based on the principle of placing materials
sterilized previously, such as containers, products and lids, in a sterile environment, and they remain
sterile throughout the operation, since people or non-sterile components are not inside the isolator.
The isolator barrier is an absolute barrier that does not allow exchanges between protected and non-
protected environments. Isolators may be physically sealed against the entry of external contaminants
or may be effectively sealed by the continuous application of overpressure. The material is handled
by employees wearing globes or half-size or full-size suits. The air coming into the isolator goes
through a HEPA or ULPA filter and the air exhaust usually goes through a HEPA filter. Vapors from
hydrogen peroxide or peracetic acid are usually employed for sterilization of surfaces or internal
environment. The sterilization inside the isolators and the entire content is usually validated for a
sterility assurance level 10-6.
The introduction of equipment, components and materials can be done in several ways, such as the
use of double-door autoclave, continuous introduction of components through a conveyor belt that
goes through a sterilization tunnel, or using a docking system. It is necessary to monitor the integrity,
calibration and maintenance of the isolator.
The requirements for controlled environments adjacent to these new technologies employed on
aseptic processing depend on the type of technology used.
Blow/Fill/Seal equipment items that limit the contact between operator and product can be installed
in a controlled environment, especially if an intervention by the operator is possible during the
production.
Barrier systems require some form of controlled environment. Due to different types and applications,
the requirements for the adjacent environment may vary. The design and operation strategies for the
environment where these systems circulate must be developed by producers using a logical and
rational criterion and the system capacity to provide sterile products must be validated according to
pre-established criteria.
In isolators, air enters through integral filters of HEPA quality or better, and their interior is typically
sterilized with a sterility assurance level of 10-6. Therefore, isolators that have sterile air do not
exchange air with the surrounding environment and are free from human operators. However, when
the isolator is in a controlled environment, the potential for contaminated product is reduced in case
of leak in gloves or suits.
The extension and scope of environmental microbiological monitoring depend on the system used.
Producers must balance the frequency of environmental sampling that requires human intervention
with the benefits accumulated by the monitoring results. Since barriers are designed to reduce human
intervention, remote sampling systems must be used to replace intervention by people. In general,
once the validation has established the barrier efficacy, the sampling frequency to monitor the
microbiological status of the aseptic processing area can be reduced when compared to the frequency
of a classic aseptic process system.
Isolator systems require lower frequency of microbiological monitoring. The continuous monitoring
of total particles may offer assurance that the air filtration system inside the isolator is operating
adequately. Traditional methods for quantitative microbiological sampling of air may not be sufficient
to test the environment inside the isolator. Experiences with isolators indicated that, under normal
operation conditions, leak or pinhole in gloves represent the highest potential for microbiological
contamination, which requires frequent glove integrity tests and monitoring of their surfaces. The
infrequent monitoring of surfaces inside the isolator must be assessed and may be beneficial.
TRAINING OF PERSONNEL
Products processed aseptically require close attention to details, rigorous discipline and the strict
supervision from people, to maintain the appropriate level of environmental quality to ensure the
product sterility.
Training all employees who work in clean rooms and zones is critical. This training is also important
for people responsible for the microbiological monitoring program, since the work area may be
inadvertently contaminated during the microbiological sampling, due to the use of inadequate
techniques. In highly automated operations, the monitoring can be performed by people who have
more direct contact with critical zones inside the processing area. The employee monitoring must be
conducted before and after work in the processing area.
The facility management must ensure that all personnel involved in operations in clean rooms and
zones knows the relevant microbiological principles, including basic principles on aseptic processing
and the relation between manufacturing procedures and manipulation with potential sources of
product contamination. They must also have knowledge on basic principles of microbiology;
microbial physiology; cleaning, disinfection and sterilization; selection and preparation of culture
media, according to the involvement of employees in the process. The personnel involved in microbial
identification requires specialized training on applicable laboratory methods. Additional training on
managing the environmental data collected must be provided. Knowledge and understanding of
standard operating procedures applicable are critical, especially the ones related to corrective
measures that are taken when the environmental conditions require. Understanding the policies for
compliance with regulatory requirements and the responsibility from each individual, related to Good
Manufacturing Practices, must be an integral part of the training program, in addition to training on
how to conduct investigations and analyze data.
The control of microbial contamination associated to people is one of the most important elements
from the environmental control program. The contamination may occur from the dissemination of
microorganisms by individuals, particularly those with active infections and, therefore, only healthy
individuals must be authorized to access controlled environments. Good personal hygiene and careful
attention to details of the aseptic gowning procedures are important items. Appropriately gowned
employees must be careful to maintain the integrity of their gloves and suits throughout the period
they are in controlled environments.
Since the environmental monitoring program is not capable of detecting all aseptic processing events
that could compromise the microbiological quality of the environment, periodical studies on culture
medium packaging or process simulation are necessary to ensure that the appropriate operating
controls and training are effectively maintained.
The sterilization processes used to prepare the culture media for the environmental program must be
validated and examined for sterility and promotion of growth. The media must be capable of
maintaining growth when inoculating with less than 100 CFU. The selection of incubation time and
temperature is made once the appropriate media have been selected. Typically, incubation
temperatures within the ranges of (22.5 ± 2.5) °C and (32.5 ± 2.5) °C have been used with incubation
times of 72 hours and 48 hours, respectively.
The environmental control program must include identification and evaluation of locations for
sampling and validating the environment microbiological sampling methods.
During the initial phase of activities, as well as in the preparation of a clean room, or another
controlled environment, specific sites for sampling air or surfaces must be determined. It is necessary
to consider the proximity of the product, whether air and surfaces in the room are in contact with it
or with internal surfaces from the container closure systems.
The sampling frequency will depend on the criticality of the sites specified and the treatment
subsequent to the aseptic process.
As manual interventions during the operation and the potential for personal contact with the product
increase, the importance of the environmental monitoring program also increases. It is most critical
for products processed aseptically than for those submitted to terminal sterilization. When the
terminal sterilization cycle is not based on the overkill concept, the microbial burden program before
the sterilization is critical. The sampling plans must be dynamic with monitoring frequencies and sites
adjusted based on the trend performance. It is appropriate to increase or reduce the sampling based
on this performance.
The principles and concepts of statistic process controls are useful to establish alert and action levels,
as well as mechanisms for controlling trends.
Alert levels are usually based on historical information obtained from process routine operations in a
specific controlled environment.
In a new facility, these levels are usually based on the previous experience from similar facilities and
processes and in data obtained throughout several weeks. These levels are usually reexamined for
suitability to a frequency established. Environmental quality deterioration trends require attention to
determine the cause and implement a corrective action plan, to bring the conditions back to expected
levels. An investigation must be implemented and the assessment of potential impact on the product
must be made.
Viable microorganisms from air may influence the microbiological quality of the products
manufactured in clean rooms and zones. The quantification of these microorganisms may be
influenced by instruments and procedures used on the assays. Employing alternative equipment or
methods must be preceded by verification on the equivalence of results. There are different ways of
monitoring different types of equipment available to quantify viable microorganisms, including
deposit, impaction and centrifugal samplers. The user is responsible for the selection and suitability
of the method to be used.
The method using deposit plates is still the one most broadly disseminated thanks to its simplicity
and low cost and provides qualitative information about the environment of exposure for prolonged
times, but the exposure of open Petri dishes containing agar medium is not for quantitative assessment
of the microbial contamination levels of critical environments.
One of the main limitations of mechanical air samplers is the size of the air sample being tested,
because the level of microorganisms in the air of a controlled environment is usually reduced and a
large volume of air must be tested for the result to be accurate and precise, which many times is not
practical. To demonstrate that the microbial counts in the environment are not increasing after
sampling, it can be extended to determine if the sampling time is a limiting factor to obtain a
representative sample. There are equipment items capable of sampling high air volume rates, but it is
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.1-00
necessary to consider the airflow rupture in critical areas or the creation of turbulence that may
increase the probability of contamination.
Centrifugal samplers demonstrate selectiveness for larger particles and, therefore, using this
equipment may result in higher counts of particles in air. When using these samplers, it is necessary
to consider their effect in the airflow linearity in the controlled zone where it is positioned for
sampling. The use of remote probes requires determining whether the extra tube used has no adverse
effect in the count of viable particles, because such effect must be eliminated, or a correction factor
must be used for the results obtained.
Sampling surfaces from equipment, areas and employees is a component from the microbiological
control program for controlled environments. To minimize the disruption of critical operations, the
sampling is usually performed at the end of the operations. The sampling can be performed using
contact plates or swab.
The monitoring is usually performed in areas that come into contact with the product and in adjacent
areas. Plates of contact with nutrient agar are used to sample flat surfaces and incubated in adequate
temperature for quantification of viable particles. Specific agar may be used to quantify fungi, spores,
etc. The swab is used in irregular surfaces, especially on equipment. The swab is placed in an adequate
diluent and the microbial count is estimated by plating an appropriate aliquot in specific nutrient agar.
The area to be sampled using swab is defined using a sterile template of appropriate size, usually
between 24 cm2 and 30 cm2. The result is given per contact plate or per swab.
The culture media and diluents used for sampling and quantification of microorganisms in clean
rooms and zones depend on the procedures and equipment used. Soybean-casein digest agar is the
solid medium usually employed, but there are different media and diluents available for different
purposes. Alternative media must be validated to the purpose used. When disinfectants or antibiotics
are used in the controlled area, it is necessary to consider employing media with appropriate
inactivating agents.
The environmental control program includes an appropriate level of identification of the flora
obtained in sampling. Knowledge of the regular flora of clean rooms and zones is important to define
the area monitoring, the effectiveness of cleaning and disinfection procedures, and the microbial
disinfection methods. The information obtained using the identification program may be useful in the
investigation of contamination sources, especially when the action limits are exceeded. The
identification of isolated microorganisms from critical areas is important.
Clean rooms and zones are monitored by an appropriate environmental monitoring program. To
ensure minimum microbial burden, additional information in the evaluation of the environment
biological status can be obtained through culture medium aseptic fill test (media fill). The media fill
test is employed to assess the aseptic processing using sterile culture medium instead of the product.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.1-00
Satisfactory media fill results demonstrate the line suitability for manufacturing the product.
However, other factors are important, such as construction of areas, environmental monitoring and
training of personnel.
When an aseptic process is developed and installed, it is necessary to qualify the microbiological
status of the process, executing no less than three consecutive media fills. Issues in the media fill
program development to be considered include procedures for filling the medium; selection of
medium; packaging volume; time and temperature of incubation; inspection of packaged units;
interpretation of results and possible corrective actions required.
Once the media fill is conducted to simulate the aseptic processing of a product, it is important that it
is conducted in normal production conditions. This includes maximum number of people and use of
all steps and materials used in the normal production process. While conducting the media fill, known
pre-documented interventions must be planned during the normal production runs, such as change of
filling nozzles, fastening components, etc. Alternatively, to add a safety margin, a combination of
possible conditions can be used and examples include frequent downtimes, unexpected repairs,
change of filters, etc.
The qualification of an aseptic process must be performed for all products and for each line. Provided
that the container geometry (such as size and opening) and the line speed are variable factors, the
appropriate combination of these factors, preferably on the extremes, must be used in the
qualification. A reasonable analysis of the products used must be documented.
It is recommended that the media fill is conducted to cover all production shifts for
line/product/combination of containers for initial qualification and periodic revalidations. The media
fill program must simulate production practices in prolonged times and may be executed at the end
of the production shift.
Rich culture media, such as soybean-casein broth, may be used. After aseptic processing of the culture
medium, they must be incubated at (22.5 ± 2.5) °C or (32.5 ± 2.5) °C, for no less than 14 days. If two
temperatures are used for incubation of culture medium samples, they must be incubated at least seven
days in each one of them. After incubation, the samples must be inspected for growth. Isolates must
be identified for genus and, when possible, for species, to allow the investigation of sources of
contamination.
Critical points when conducting the media fill are number of containers to qualify the aseptic process;
number of units filled for the media fill; interpretation of results; and implementation of corrective
actions. Usually, three media fill runs are employed for initial qualification, or in the beginning of an
area to demonstrate consistency in the aseptic packaging line. The minimum number to demonstrate
the contamination rate of no more than 0.1%, acceptance criterion for a media fill run, is of no less
than 3000 units. Pilot plans that prepare small batches can use a smaller number of units.
Since employees are a critical source of contamination in clean rooms, visual documentation may be
useful to check the correlation of production activities with contamination events.
Parametric release is defined as the release of cargo or batches of products subject to terminal
sterilization, through compliance with critical parameters of the sterilization process, without the need
to perform a sterility test. The parametric release is a possibility when the sterilization process is very
well known, the important process control points are defined, predictable and measurable, and the
sterilization cycle lethality has been validated with adequate biological indicator or, in the case of
sterilization by ionizing radiation, the execution of appropriate microbiological and dosimetry tests.
The use of parametric release for sterilization processes requires prior approval from the regulatory
agency, which must assess the scientific justification for the sterilization process employed and the
documented validation data.
It is important to consider the sterility test limitations in the assessment of products submitted to
terminal sterilization, which has compromised sensitivity and is statistically limited due to the low
probability of presence of contaminated units. Therefore, once the sterilization process is completely
validated and operating consistently, the physical sterilization data, combined with other methods,
such as biological indicators, thermochemical indicators and physicochemical indicators, may
provide more accurate information than the sterility test for releasing products submitted to terminal
sterilization.
Four sterilization processes can be qualified for parametric release: moist heat, dry heat, ethylene
oxide and ionizing radiation. Products submitted to terminal sterilization represent the lowest risk
category among sterile pharmaceutical products. Contrary to sterile products obtained by aseptic
production in controlled environments, products submitted to terminal sterilization present a
measurable sterility assurance level.
Sterile products obtained by terminal sterilization must meet a sterility assurance level of 10-6, that is,
no more than one contaminated unit in one million units produced. The appropriate application of
methods used for development of terminal process requires vast scientific knowledge of the
sterilization method selected, in three categories, for use with a specific product:
a) process based on microbial burden (bioburden);
b) combined process: biological indicator and bioburden;
c) overkill process.
The process based on bioburden requires vast knowledge of the product microbial burden. It must be
observed that different procedures for establishing the dose in the process of sterilization by radiation
use the knowledge on the product microbial burden and its resistance to radiation. This method also
requires a sterility assurance level of at least 10-6. The method based on determination of bioburden
needs the development of critical process control points concerning the product microbial burden.
Risk analysis procedures, such as Hazard Analysis and Critical Control Point (HACCP), are useful
to establish manufacturing control conditions and appropriate parameters of control in process.
For products that allow microbial burden survival, more controlled production environments and
more precise process controls are necessary. This process is more indicated for clean products, with
reduced level of microbial burden and low frequency of spore-forming microorganisms. This process
may also be useful for products that may suffer changes when submitted to more drastic sterilization
processes.
The combined process that uses biological indicator and bioburden is usually employed for products
that may lose attributes when using overkill process and when a sterilization process that demonstrates
the inactivation of high numbers of microorganisms from biological indicators, recognized as more
resistant to the sterilization process, is desired. This process requires knowledge of the product
microbial burden and data related to its resistance to the sterilization process. The relative resistance
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.1-00
of the biological indicator selected must be established by inoculation of microbial spores in the
product. Usually, biological indicators with 106 spores and D value higher than one minute are
employed. Fractional cycles are used to determine the relative resistance (D value) between the
product inoculated with microorganisms from the biological indicator and those frequently found on
the microbial burden. This process is usually employed for development of cycles for sterilization of
parenteral products using terminal sterilization and sterilization of correlates by ethylene oxide.
The overkill process is used when the product to be sterilized is not harmfully influenced by the
sterilizing agent or sterilization process conditions. When employing this process, it is important to
know the product microbial burden and the prevalence of spore-forming microorganisms. In this case,
data on microbial burden do not need to be thorough like for the other two processes (bioburden and
biological indicator/bioburden). Usually, biological indicators are resistant to the process. Overkill is
demonstrated by the log reduction of spores from the biological indicator, calibrated in a process that
allows obtaining minimum F0 of 12 minutes.
The parametric release requires the sterilization process selected to be developed and constantly
validated, for inactivation of the microbial burden and for achieving a sterility assurance level of 10 -
6
. The validation of most sterilization processes includes the validation of physical parameters and
the microbiological effectiveness through the use of biological indicators to demonstrate a reasonable
correlation between the lethality obtained through physical measurements (F0) and the biological
lethality determined with the use of biological indicators.
Once the efficacy of the terminal sterilization process defined due to the bioburden is associated to
the number and resistance of microorganisms in the product, one of the components of parametric
release is the active microbiological control program to monitor the count and resistance of the
product microbial burden. The control of microbial burden and its enumeration is not a crucial factor
when the overkill method is employed, because, in general, the overkill method does not require
extensive assessment of the microbial burden throughout the process and requires less control in
production environment process.
Symbol Definition
a1...z1 doses of assayed preparations (samples) A...Z.
a statistic significance of a result or estimated measure of the degree where this result is
“true”
b0 intersection of responses (y) over log doses (x) in the regression line.
b, b1 estimated slope of the response regression line (y) in relation to the dose logarithm (x).
bl number of blocks (animals) in a crossover trial.
c’ constant used in the assessment of confidence limits (Table 15).
d number of levels of doses for each preparation in a balanced assay.
f number of differences in paired responses between standard and samples, on assays
conducted by 5 x 1 design.
gl degrees of freedom.
h number of preparations in an assay, including the standard preparation.
h’ number of samples tested.
k number of different treatments in an assay k = dh.
k’ number of potency logs in assays conducted by the 5 x 1 design, for the same sample.
n number of replicas for each treatment.
n’ number of individual potency estimates.
n’’ degrees of freedom used to estimate the s2M variance on the 5 x 1 assay
p probability
p1p2p3 lowest, average and highest doses of the standard preparation P; in assays with only two
levels of doses, p2 represents the highest dose.
r Pearson correlation coefficient
s2 estimate of variance provided by the average square of error in the variance analysis. Also
used as an index letter; for example, s2 represents the M log potency variance.
s estimate of standard variation, that is, the square root of s2.
t Student statistic (Table 3).
t’ Dunnett statistic (Table 12).
v variance for heterogeneity between assays.
w weighting coefficient.
x log dose – also used with index to indicate a particular preparation.
𝑥̅ average of log doses.
y individual response or transformed individual response.
y’ calculated response to replace a missing value.
𝑦̅𝑃 … 𝑦̅𝑍 average of responses for standard and sample preparations.
A...Z samples tested.
A1A2A3 sum of responses for the lowest, average and highest doses of sample A. For an assay with
two levels of doses, A2 represents the response to the highest dose. Similarly for other
samples tested.
Symbol Definition
B1...B2n sum of responses for each subject (1 to 2n) in double crossover trial.
B’ incomplete total of responses in row or block that has a missing value.
C statistics used in the calculation of confidence limits (Formula 14).
C1...Cn sum of responses in each column (1 to n) in Latin square design.
C’ incomplete sum of responses in a Latin square design column with a missing value.
CV coefficient of variation.
X2 statistics constant from Table 18.
X2M statistics constant to test the homogeneity of individual log potency estimates.
E sum of squares for regression (Table 10).
F ratio of two estimates of independent variances (Tables 4 and 5).
FI, FII sum of responses on phase I or phase II in a crossover trial.
F1...Fn sum of responses in each one of the row 1 to n in Latin square design or in each block from
a randomized block design.
G1, G2, G3 statistics used in the outlier values test.
G’ incomplete total of responses in an assay with exclusion of missing value.
I interval between adjacent log doses, in the parallel straight assay.
K correction term used in the analysis of variance K = (∑y)2/N.
L Confidence interval in logarithms.
LC confidence interval in logarithms for semi-weighted average.
LP...LZ linear contrasts for standard and sample preparations.
M estimative of log potency or log potency ratio used with an index letter in a multiplex assay,
to denote a particular preparation (M = log R).
Mi, Ms confidence limits of the log potency estimate.
M average of several independent estimates from M.
M’ estimate of log potency from sample A or log potency ratio before correcting by the
supposed potency (M’ = log R’).
M’s, M’i upper and lower limits of the log potency estimate, before correcting with the supposed
estimate.
N total number of responses from assay.
NP, NA total number of responses for preparations P and A.
P standard preparation.
P sum of responses for standard preparation.
P1, P2, P3 sum of responses for lowest, average and highest doses of standard preparation P. For
assays on only two levels of dosage, P2 represents the responses for the highest dose.
Q sum of squares for linearity in the same direction (Table 10).
QM sum of squares due to a source of variation divided by the respective degree of freedom.
QP...QZ quadratic contrast for standard and sample preparations (Table 9).
R estimated potency of the sample.
Ri, Rs upper and lower confidence limits of the estimated potency.
R’ estimated ratio of potencies before the correction by the assumed potency.
R+ specific constant to test atypical values (Table 2).
SA assumed potency for sample A, when the doses are prepared.
SQ sum of squares due to a source of variation.
T’ incomplete total of responses to a treatment excluding the missing value.
V = 1/W variance of the individual log potency.
Symbol Definition
X differences in paired responses between sample and standard, divided by the regression
coefficient (b1), in the 5 x 1 design.
W statistical weighting used in the combination of several independent estimates of log
potency.
W’ semi-weighting of each log potency in a series of assays.
χ2 chi-square statistics (Table 18).
Note: Tables 1 to 20 are available on section 8.9 STATISTICAL TABLES. Tables 21 to 47 are
available on section 8.10 EXAMPLES OF STATISTICAL TESTS.
FUNDAMENTS
BIOLOGICAL ASSAYS
Procedures designed to assess the potency of active ingredients contained in raw materials and
pharmacopoeial preparations, using biological reagents such as microorganisms, animals, fluids and
isolated organs from animals. The characteristic of biological reagents is their variability While
physicochemical reagents may be defined and standardized to provide identical results in all
laboratories, it is impossible to completely define the biological reagents, despite efforts from
international entities in this sense. This variability inherent to biological reagents makes it mandatory
to: 1) employ adequate reference standards to obtain relative potencies, and 2) employ statistical
methods for experimental designs and analysis of results.
EXPERIMENTAL DESIGNS
The design of an assay includes: a) selection of the set of standard doses (P) and samples from the
unknown (A) that will be tested; b) specification of experimental units (animals, microorganisms,
antisera, blood, etc.); c) rules by which the doses will be distributed to the experimental units; d)
specifications on measures or other registrations that must be carried out in each experimental unit.
The best experimental design is the one that produces the information desired with the most
efficiency. Due to practical difficulties, it may be impossible to achieve this goal. Therefore, for each
assay different experimental designs can be used, according to the availability of personnel, reagents
and time. All designs that provide valid assays with adequate precision as result are scientifically
acceptable. Additionally, they must include a system that ensures random distribution of experimental
units for the different doses used.
The distribution must be made randomly using a device employed in games of chance or a random
number table. It is worth highlighting that this procedure does not eliminate all biases. For example,
due to chance, animals with more weight may be targeted to a certain dose, and this difference in
weights will bias the results. Therefore, a balance must be created, that is, animals must be classified
by weight range and those with the same weight must be distributed randomly for all doses and
preparations (standard and sample).
STATISTICAL ANALYSIS
It is the mathematical procedure applied to experimental results with the goal of estimating the sample
potency and assessing the validity and precision of the assay. The analysis methods are related to the
experimental designs used.
RESULTS
Express the results from the biological evaluation as an estimate of the assumed potency for a sample
(R), which will be the expression of the true relative potency of the sample in relation to the standard
(ρ). The latter is impossible to be calculated accurately due to the variability of biological reagents.
Such estimate of the assumed potency (R) must be followed by the lower and upper confidence limits
(Ri, Rs), or interval that encompasses the true relative potency of the sample (ρ). The monographs
establish specifications for the acceptable amplitude of these intervals in relation to the estimated
potency. These specifications take into account the difficulty of the methods and the practical need
to estimate the true potency with certain precision. To achieve the confidence limits specified, it
sometimes is necessary to conduct more than one assay. To obtained an estimate of potency with
reduced confidence interval, the results from these independent assays must be combined statistically.
The probability, which measures the degree of confidence that the potency is out of the upper and
lower confidence limits, is given by the statistical significance (α) of a result or estimated measure of
the degree in which such result is “true”. The level of significance most used in biological assays is
5% (α = 0.05) or 1% (α = 0.01). In cases not explicitly specified, it will be understood that the level
of significance used in the calculation of limits is α = 0.05.
The calculation procedures are planned for assay in single sample. If several samples are tested
simultaneously, employ the modifications described in this volume.
ATYPICAL VALUES
All responses obtained without strictly complying with the protocol pre-established must be
eliminated. When apparently atypical values are observed after the responses are registered, the
decision to maintain or eliminate them must be based on statistical criteria, like the ones described
below:
In average, for relatively few identical responses inside the group, valid observations will be
disregarded in 2% or 4% of the tests. Starting with the supposedly atypical value, indicate responses
in order of magnitude from 𝑦1 to 𝑦𝑛, where n represents the number of observations in the group or
replicas of the same treatment. Calculate:
If G1, G2 or G3 exceeds the critical value registered on Table 1 for the corresponding value of n, there
is a statistical base for elimination of the suspicious value.
Criterion that includes the amplitude of a series K = 2 or more groups of equal size
The groups may receive different treatments, but all n responses inside each group result from the
same treatment. In this test, the variation of values for each treatment, obtained by the difference
between the highest and the lowest values, is studied. The value obtained with greater difference must
be divided by the sum of all differences and must not exceed the listed value of (R+) on Table 2 for
k = number of doses and n = number of replicas. If the value calculated exceeds the value listed, the
suspicious column must be investigating to detect the discrepant value. If k is lower than or equal to
10, use the values presented on Table 2; if it is higher, multiply R+ by (k + 2) and interpolate, if
necessary, between the values presented on Table 2a.
If R+ exceeds the listed or interpolated value, the group with highest interval is suspicious (α = 0.05)
and the observation of its data will allow identifying the value that is then considered atypical. The
procedure can be repeated with the other intervals if there an atypical value is suspected in a second
group.
DIRECT ASSAYS
The doses from each preparation (sample and standard) necessary to produce pre-determined
responses in each experimental unit from two equivalent groups of animals or other biological
reagents are measured directly. A typical example is the biological assays of a fingerprint. Prepare
the standard and sample solutions so that they have approximately the same potency, taking into
account the declared activity of the sample or the activity estimated in previous tests (𝑆𝐴). Transform
each result (effective dose) into logarithms (x) and calculate the average values of the logarithms from
effective doses for the standard (𝑥̅𝑃) and the sample (𝑥𝐴). Calculate the relative potency of the sample
(R’), before adjusting by the assumed potency, such as the M’ antilog, where:
Calculate the variance of M’ as the sum of variances from the two averages, from the equation
2
1 1
𝑆𝑀′ = 𝑆𝑥2 ( + ) (2)
𝑁𝑃 𝑁𝐴
where
NP and NA are numbers of animals treated as standard and sample; ∑𝑃 𝑒 ∑𝐴 representam sum of
results calculated for the two preparations. Calculate the confidence limits as:
𝑅′𝑠
= 𝑎𝑛𝑡𝑖𝑙𝑜𝑔 (𝑀′ ± 𝑡𝑆𝑀′ ) (4)
𝑅′𝑖
Obtain the appropriate value of t on Table 3, according to the degrees of freedom (gl) provided by
the equation denominator (3).
Calculate the relative potency of the sample and the confidence limits, taking into account the
assumed potency of the sample (SA) used to prepare the dilutions:
𝑅 = 𝑎𝑛𝑡𝑖𝑙𝑜𝑔 𝑀 (5)
where
𝑀 = 𝑀′ + log 𝑆𝐴 (6)
𝑅′𝑠
= 𝑎𝑛𝑡𝑖𝑙𝑜𝑔 (𝑀′ ± 𝑡𝑆𝑀′ ) (7)
𝑅′𝑖
For the assay to be valid, the variance of xP must be the same as xA, only differing by sampling errors.
To test, calculate the variances and divided the highest by the lowest. This way, a relation of variances
(F) is obtained.
The distribution of ratio of variances (F) is available on Tables 4 and 5, but for this test the values on
Table 4 correspond to the significance levels α = 0.05 and the ones on Table 5 to α = 0.01. The F
value of the assay must not exceed the value on the table, corresponding to the degrees of freedom of
the numerator and denominator with which F was obtained. The degrees of freedom are the ones of
the denominators from variances of equations (8) and (8a).
In general, it is not possible to directly measure the effective dose. For this reason, the potency is
determined indirectly, comparing the responses produced in quantitative scale, such as weight, for
example, by known doses of standard with the ones produced by one or more doses of sample.
In a restricted interval of doses, the responses or their convenient transformation (logarithm, probit,
etc.) present a linear relation with the logarithm from corresponding doses. Use two or more levels of
doses of standard or, preferably, of standard and sample to determine the position and straight line
slope. Proceed the same way in each assay, because, depending on the sensitivity of the biological
reagents used, both the position and the straight line slope may vary.
Each treatment consists of a fixed dose of standard (p1, p2, p3, etc.) or of sample (a1, a2, a3, etc.) and
is administered to a certain number (n) of experimental units (animals, organs, cultures, tubes, etc.).
Register n responses, that is, one for each experimental unit. For the methods presented in this chapter
to be valid, the following conditions must be met:
1) the experimental units corresponding to each treatment must be selected randomly;
2) for each treatment, the responses or their transformations used in the calculation (y) constitute a
sample of normal distribution;
3) the standard deviation of the response or its transformation is independent from the response
level, that is, it is equal for all treatments, only differing by sampling errors;
4) the response, or its transformation used in calculations (y), has linear relation with the logarithm
from dose (x) in the interval of doses used;
5) the straight line corresponding to one or more samples must be parallel to the one from the
standard.
From preliminary studies on the assay method, it is possible to suppose that the conditions 2 and 3
are met. With the results from each assay, it is possible to test the conditions 4 and 5. The condition
4 (linearity) can only be verified in assays that apply at least three dilutions from each preparation.
When an assay is conducted with only two dilutions, it is presumed that the system linearity was
established in advance. The condition 5 (parallelism) must be tested in each assay. Less than two
dilutions from each preparation must never be used in it.
If any of the conditions from 1 to 5 is not met, the calculation methods described in this chapter cannot
be applied and it is necessary to conduct studies to establish the conditions recommended.
It is convenient that the sample is tested with doses which responses are approximately equal to the
ones obtained with the corresponding doses of the standard. This increases the precision of the result.
Name the assumed potency for the sample SA.
When the corresponding validity tests are conducted and the results are satisfactory, it is possible to
express the relative potency of each sample in relation to the standard with a potency ratio or convert
into appropriate units for each sample, for example, international units, national units, weight units,
etc. The confidence limits can also be calculated from the set of data obtained in the assay.
To simplify the calculations from the statistical analysis presented in this chapter, it is necessary to
impose the following limits to the assay design:
a) test each preparation, standard and sample with the same number of dilutions. Formulas are
presented for pharmacopoeial assays, using two and three levels of doses for each preparation, as well
as the 5 x 1 design;
b) keep constant in each assay the ratio of consecutive doses for all treatments and
c) obtain the same number of responses for each treatment. If any response is missing, it may be
estimated by methods suitable to each design presented in this chapter; if there is loss of a treatment,
follow the specification on the section Partially balanced assays.
TYPES OF DESIGN
Random
When experimental units are, in their totality, reasonably homogeneous and there is no indication that
the variability of response may be smaller in certain subgroups, proceed to the distribution of
experimental units for different treatments randomly.
If there is the possibility that some subgroups, such as layers, positions on shelves or experiment days,
are more homogeneous than the totality of units, the accuracy of the assay may be increased by
introducing one or more restrictions to the experimental design.
Randomized blocks
It allows to segregate a source of variation, such as the sensitivity of different animal litters or the
variation between Petri dishes in the microbiological assay by diffusion. This planning makes each
treatment be applied once in each block (litter, plate, etc.) and can only be executed when the block
is sufficiently large to accommodate all treatments.
Crossover
Use this planning when the experiment can be adjusted in blocks. However, it is only possible to
apply two treatments per block. For example, a block can be an animal that can be tested in two
different occasions. The goal is to increase the precision, eliminating the influence from the variation
of animals, at the same time the effects from any difference between the overall response levels, in
the two steps of the assay, are balanced. Denominate as double crossover the assay with two doses of
standard and sample and as triple crossover the one with three doses of each preparation. Proceed to
the assay in two phases according to the period of time defined in the method. Distribute the animals
in four or six groups and make a treatment in each group on the first phase. On the second phase, the
animals that received a preparation will receive another; the animals that received lower doses will
receive higher doses in this step. Follow the scheme on Table 6.
Latin square
Adequate when the response can be affected by two sources of variation, and each one may have
different k levels. For example, the experiment is conducted in k different day and by k testers, or an
antibiotic assay by diffusion on plate is conducted, where the treatments can be applied on a k × k
scheme, where each treatment occurs only once in each row and each column. Use only when the
number of columns, rows and treatments are equal.
The responses are registered in the form of a square named Latin. There are many possibilities of
Latin squares found in specialized literature. From one square other squares can be made, alternating
randomly rows and/or columns. On Table 7 there is an example of Latin square with two doses of
standard and of sample.
For any design, the distribution of experimental units in the blocks must be done randomly by
procedure, with the units being maintained as seamlessly as possible before and during the
experiment.
ANALYSIS OF VARIANCE
When conducting this analysis, the goal is to study the validity of the assay and calculate the residual
error. Except for the calculation of residual error, the analysis of data from an assay is identical for
random, randomized blocks and Latin square designs. The formulas for analysis of each type of assay
are described below. Please refer to the glossary of symbols. The formulas are appropriated for the
case where a single sample (A) is compared against the reference standard (P), and also for the case
of multiple assays where h-1 samples are included (A...Z). The formulas for crossover assays do not
fit the general scheme and will be presented separately.
If necessary, transform the responses (y) to meet the validity conditions described. Sum all y values
for each treatment and for each preparation, as seen on Tables 8 and 9. From these data, obtain the
linear contrasts related to the dose-response line slopes.
When three doses of each preparation are tested, quadratic contrasts that represent the line curvatures
are also obtained. See the formulas on Tables 8 and 9.
The total variation of responses resulting from different treatments can be as displayed on Table 10.
The sums of squares are obtained from values on Tables 8 or 9. K represents the square of the sum
of all responses obtained on the assay divided by their total number:
𝐾 = {(∑ 𝑦)²/𝑁}
Calculate the residual error from the assay by subtracting the controlled variations in the design from
the total variation in responses (Table 11). In this table, Σy2 represents the sum of squares from all
responses registered in the assay. It is worth highlighting that the sum of squares, reduced,
corresponding to the item Treatments is equal to the sum of reduced square sums (Table 10) and that,
for Latin square, the number of responses replicated (n) is equal to the number of rows, columns or
treatments (k).
TESTS OF VALIDITY
To test the significance of the sources of variation listed on Table 10, each reduced sum of square
obtained on the table must be divided by the corresponding degree of freedom to obtain the average
square. The average square of residual error (s2) is a similar quotient, obtained from the appropriated
row on Table 11.
To obtain the ratio known as F, divide the average square from each source of variation to be tested
by the variance (s2). Calculate the significance of each source and compare with the values listed
(Tables 4 and 5) to the significance level of 5% (α = 0.05) and 1% (α = 0.01). The F values are
obtained in the column corresponding to the number of degrees of freedom associated to the average
square of the source tested (𝑔𝑙1) and on the table row corresponding to the number of degrees of
freedom associated with s2 (𝑔𝑙2). If the F value calculated is higher than the value listed, the source
of variation tested is considered “significant” for the level of probability used.
Consider the assays “statistically valid” if the tests present the following results:
1) Significant regression, that is, F calculated is higher than the one listed at the significance level
of 1% (α = 0.01). It indicates that the dose-response row is satisfactory;
2) Non-significant quadratic terms, that is, the F values calculated must be smaller than the ones
listed at the significance level of 5% (α = 0.05). It is equivalent to meeting the linearity condition of
the relation between the transformation of the response used and the log dose;
3) Non-significant parallelism, that is, the F calculated must be lower than the value listed at the
significance level of 5% (α = 0.05) indicating that the straight lines from the sample and standard are
parallels. If several samples are being tested simultaneously, and a significant deviation of parallelism
is obtained, this may occur due to the use of a preparation that provided a dose-response row with a
different slope in relation to the other samples. In this case, use the value of t’ for each A...Z
preparation, using the equation
𝐿𝑃 − 𝐿𝐴
𝑡′ = (9)
2𝑠√𝑛
Each t’ calculated must be compared with the value from Table 12, where 𝑔𝑙1 = h -1 and 𝑔𝑙2 equals
the number of degrees of freedom associated with s2. If a “significant” value of t for a sample is found,
all data related to this preparation must be eliminated from the assay and the analysis must be repeated
from the beginning.
In assays with very large residual error, a “significant” F ratio for the term Preparations may indicate
that the assumed potency that was the base for preparation of dilutions was not correct. This is not a
condition for invalidity. When this conclusion is reached, the potency estimated on the assay can be
used as assumed potency in future assays.
On parallelism and quadratic assays, very low F values, lower than 1, may occur randomly. If this
occurs repeatedly, it may be an indication that the assumed conditions were not met, which must be
investigated more deeply.
5 x 1 design
In the case of crossover assays, with a special calculation scheme, the formulas to be used are
available on Tables 13 and 14.
There are three terms of interactions due to replicas within each group: Phases X Preparations, Phases
X Regression, and Phases X Parallelism.
Like in designs discussed previously, each reduced sum of squares must be divided by the
corresponding number of degrees of freedom to obtain the average squares.
In the case of double crossover design, two average squares are obtained corresponding to errors I
and II, named s2I and s2II. Divide the average square of each source of variation by the appropriate s2
to obtain the F ratio.
For the sources Parallelism, Phases X Preparations, Phases X Regression, s2I is used. For the other
sources, s2II is used.
Calculate the significance of the source using the Tables 4 and 5. If F calculated is higher than the
value listed, for the degrees of freedom of the source tested (𝑔𝑙1) and the corresponding s2 (𝑔𝑙2), the
source of variation is considered “significant” for the significance level used (α = 0.05 or α = 0.01).
For the assay to be valid, the regression must be significant and the parallelism and three interactions
must not be significant. In the crossover assay, the parallelism test is not very sensitive, because it
depends on the variation between blocks (animals).
With the statistical validity of the assays done with any design being established, calculate the potency
and the confidence limits by the methods described below.
Calculate first the average response for each preparation (𝑦̅𝑃 , 𝑦̅𝐴 , … 𝑦̅𝑍 )
P
y̅P = (10)
NP
Naming I the interval in log of the concentrations, for each preparation, the common slope (b) is
obtained on assays with two doses, from the equation
LP + LA + ⋯ LZ
b= (11)
I𝑛ℎ
For assays with three doses of each preparation, the denominator Inh must be replaced with 2 Inh.
The log potency ratio from sample A (M′A), before correcting by the value of SA, is
y̅A − y̅P
M′A = (12)
b
The potency calculated is the estimate of the true potency from each sample. The confidence limits
(with 5% of probability to exclude the true potency or α = 0.05) can be calculated as the antilog of
the formula
where
E
C= (14)
(E − s2 t 2 )
Obtain E from Table 10. s2 is the residual error from Table 11 divided by its degrees of freedom and
t is available on Table 3 according to the degrees of freedom from s2.
For balanced assays of two to three doses per preparation, the formula for the limits from equation 13
can be simplified:
M′AS
= M′A ± √(C − 1)(𝐶𝑀′𝐴2 + 𝑐 ′ 𝐼 2 ) (15)
M′Ai
where c’ is the coefficient obtained on Table 15 and C is the measure of significance of regression.
In an assay with a well defined slope, the C value will be very close to the unit.
Procedure for building the dose-response curve In the turbidimetric method, measure the turbidity
on tubes with liquid medium.
In the agar diffusion method, measure the zones of inhibition for each concentration of standard (P1,
P2, P3, P4, and P5) in the four sets of plates. The average of 36 readings of intermediate concentration
of standard (P3) is used to correct the averages from each one of the other concentrations of standard
P1, P2, P4, P5.
The correction is made as follows: measure the 36 readings of P3 in all plates and calculate the
average. Measure the nine readings of P3 in the set of plates (3) for the other concentrations (P1, P2,
P4 and P5) and calculate the average. Calculate the difference between the total average and the
average on the three plates of each concentration, which must be added to the measures of the other
concentrations.
Example:
Build the table with the responses corrected for the respective concentrations (P1 to P5) according to
Table 19 and conduct the analysis of variance. With the validity of results confirmed, calculate the
differences in paired responses between sample and standard on the central point of the curve by the
equation
(𝑦𝐴 − 𝑦𝑃 )
X= (16)
b1
where 𝑦𝐴 is one of the responses from the sample among the f repetitions, 𝑦𝑃 is the paired response
from the standard, and b1 is the regression coefficient given by Table 20.
where f is the number of differences in the paired responses between the sample and the respective
standard.
When a number of assays from the same sample is obtained through the same curve, calculate the
coefficient of variation (CV) for the results from samples.
∑ 𝑦2 −(∑ 𝑦)2 /𝑁
where s = √ and y is the response from 1 to N for the same sample. (18a)
𝑁−1
The variance is calculated over the f values of X for the total of samples tested as
2
∑ 𝑋 2 − ∑(𝑇𝑥 2 /𝑓)
𝑆𝑀 = (19)
𝑛′′
where Tx = ΣX for a single sample and 𝑛′′ = ∑ 𝑓 − ℎ′ 𝑒 ℎ′ is the number of samples tested.
𝑡
2𝑆𝑀
𝐿= (20)
√𝑘′
where s is the standard deviation for the total of differences X, t is available on Table 3 with the
2
degrees of freedom from 𝑆𝑀 and 𝑘′ is the number of differences paired by sample tested.
The confidence limits (with 5% of probability to exclude the true potency) can be calculated with the
antilog of the formula
M′AS
= M′A ± 1/2L (21)
M′Ai
Obtain the potency ratio (RA) and the confidence limits (Rs, Ri) taking the antilogs of the values
obtained from formulas 12 and 15 (parallel line design 3 x 3 or 2 x 2) and 17 and 21 (5 x 1 design),
after adding log SA to both:
R A = antilog MA (23)
Missing values
In balanced assays, the same number of observations is required for each concentration. If any
response is missing due to a cause not related to the treatments applied, such as death of an animal or
rupture of a test tube, the statistical analysis becomes much more complex. The equilibration may be
reestablished in two manners:
1) reduce the number of observations in larger groups until the number of responses is the same for
each treatment. If the design is completely random, the average from each larger group can be
subtracted, as many times as necessary, or one or more responses from each larger group can be
eliminated, by selecting them randomly. For randomized blocks assay, maintain only the full blocks;
2) alternatively, a group, casually smaller, may be recomposed to the original size, when the number
of missing responses is not higher than one in any treatment or 5% in the total from the assay. In this
case, calculate the missing value replacement. A degree of freedom is lost in the variance from error
s2 for each value replaced:
a) if the design is completely random, replace the missing value with the average of the remaining
responses from the incomplete group;
b) if the design is of randomized blocks, replace the missing value by applying the formula
′
𝑛𝐵 ′ + 𝑘𝑇 ′ − 𝐺′
𝑦 = (26)
(𝑛 − 1)(𝑘 − 2)
where B’ is the incomplete total of responses in the block that has the missing value, T’ is the
incomplete total of responses in the treatment that has the missing value, G’ is the total sum of
responses obtained on the assay. As defined previously, n is the number of blocks and k is the number
of treatments or doses;
c) if the assay is based on Latin square design, the missing value (y’) is obtained by the equation
𝑘(𝐵 ′ + 𝐶 ′ + 𝑇 ′ ) − 2𝐺′
𝑦′ = (27)
(𝑘 − 1)(𝑘 − 2)
where B´ and C´ are the sums of responses on rows and columns, respectively, that have the missing
value. In this case, k = n.
If more than one value is missing, replace, temporarily, with the average from the respective
treatment, all empty places, except one. Substitute this place with the value y’, calculated by equation
27. Substitute one by one the values that had been placed, temporarily, with the average until
obtaining a stable set of values for all missing responses.
If the number of values replaced is small in relation to the total number of observations in the assay
(lower than 5%), the resulting approximation of replacements described and the reduction in the
degrees of freedom, equivalent to the number of values replaced, is usually satisfactory. However,
the analysis must be interpreted carefully, especially if there is predominance of missing values in a
particular treatment or block. The same is valid for the case of missing values in crossover plannings.
If the assumed potency of samples (used to calculate the assay doses) is very different from the actual
potency, it is possible that the larger dose provides maximum response or that the smaller dose
provides very low or null response. These responses will be out of the linear zone from the log dose-
response curve and the validity tests will indicate the curvature and/or “significant” deviation from
parallelism.
In this case, the responses to the larger or smaller dose from the sample can be disregarded, calculating
a relative potency value from remaining data. This potency can be taken as the supposed potency to
select doses of sample for another assay, with the goal of obtaining responses similar to standard and,
thus, increase the precision of the result. The equation employed to calculate the potency is:
𝑦̅𝐴 − 𝑦̅𝑃 1
𝑀′𝐴 = ± (28)
𝑏 2
This formula is similar to formula 12, but half of the log dose interval is subtracted when the responses
from the lower dose are omitted and the same interval is added when the larger dose is disregarded.
The average responses 𝑦̅A and 𝑦̅P are obtained from the same formulas in totally balanced assays
(formula 10), but a modification must be introduced in the calculation of slope (b) according to the
assay design.
For multiple assays, which would necessarily have two doses of each preparation, the linear contrasts
(LP ... LZ) must be formed excluding LA (since the responses for 1 or 2 were eliminated, it is not possible
to form a contrast LA). Calculate the slope from the average of values from L divided by In:
𝐿𝑃 + ⋯ + 𝐿𝑍
𝑏= (29)
𝐼𝑛(ℎ − 1)
𝐿𝑃
𝑏= (30)
𝐼𝑛
For multiple assays with three doses from each preparation, obtain LA and the other contrasts from
Table 9. The equation for the slope is:
2(𝐿𝑃 + ⋯ + 𝐿𝑍 ) + 𝐿𝐴
𝑏= (31)
𝐼𝑛(4ℎ − 3)
2𝐿𝑃 + 𝐿𝐴
𝑏= (32)
5𝐼𝑛
MOVING AVERAGES
In the particular case of heparin bioassay, the interval between the dose that allows coagulation and
the one that inhibits it is so small that the dose-response curve cannot be determined explicitly. To
interpolate the log dose corresponding to 50% of coagulation, both for the standard and for the sample,
moving averages are used.
Calculation of potency
Transform in a logarithm the volumes of standard preparation used in five or six tubes that comprise
the series, so that two or three tubes present coagulation degrees equal to or lower than 0.5 and two
or three tubes have degrees equal to or higher than 0.5.
Build a table correlating the tubes numerated, consecutively, with the degree of coagulation observed.
Denominate x the logarithms of the volumes used and y the corresponding degrees of coagulation.
Calculate the paired averages xi and yi from tubes 1, 2 and 3; from tubes 2, 3 and 4; and from tubes 3,
4 and 5, and when the series is comprised of six tubes, from tubes 4, 5 and 6, respectively. If for one
of these pairs of averages the average degree of coagulation yi is exactly 0.50, the corresponding xi is
the median of the log volume of standard preparation xp. If this does not occur, interpolate xp from the
paired values of yi, xi and yi+1, xi+1 that occur, immediately below and above the degree 0.50, as:
From paired data obtained on the sample tubes, calculate in the same manner the median of the log
volume xA. The log potency of the sample is:
𝑀𝐴 = 𝑥𝑃 + 𝑥𝐴 + log 𝑆𝐴 (34)
where SA is the assumed potency of the sample made in the preparation of the corresponding solution
from the sample tubes.
Repeat the assay, independently, and calculate the average from two or more M values to obtain M ̅.
If the second determination of M is different from the first one more than 0.05, continue conducting
assays until the logarithm of the confidence interval, calculated according to the end of section
Combination of potency estimates, does not exceed 0.20.
The potency of heparin sodium is:
̅
R = antilog M
The formulas of sums of squares for the validity test are the same used in quantitative indirect assays
(Table 10), taking n = 1, except for the term error (s2), which has degrees of freedom equal to infinite,
and is calculated as:
𝑘
𝑆2 = (35)
𝑛∑𝑤
Calculate the potency and the confidence limits using the formulas 12 and 25. This approximate
method is useful when the assay is designed so that the responses in percentages corresponding to the
lower and higher doses are evenly spaced around 50%. If one of the doses tested provides zero or
100% responses, they can be disregarded. In this case, obtain the estimated potency by the methods
described on section Partially balanced assays.
Assume that results from n assays were analyzed to provide n’ M values with confidence limits (in
logarithms) associated to each M value, obtained according to equations 13 to 15 and 22 to 25. For
each assay, obtain the log confidence interval (L), subtracting the lower from the upper limit. Also
calculate a weight (W) for each M value from equation 36, where t is the same value employed in the
calculation of the confidence interval:
4𝑡 2
𝑊= 2 (36)
𝐿
For each assay, calculate the product WM and divide its sum by the sum of all weights, to obtain the
logarithm of the weighted average potency (M), according to equation 37:
̅ = ∑ WM / ∑ W
M (37)
n′ n′
̅ = ∑ WM / ∑ W
M
𝑛′ 𝑛′
The standard error of the average potency (sM̅ ) is the square root of the converse from total weight:
SM
̅ = √1/ ∑ 𝑊 (38)
𝑛′
SM
̅ = √1/ ∑ 𝑊 (38)
𝑛′
Calculate the approximate confidence limits (α = 0.05), from the antilog of values obtained through
formula 39:
̅ ± tsM
M ̅ (39)
The t value on Table 3 is obtained, with degrees of freedom equivalent to the sum of the degrees of
freedom from the variance of error from individual assays.
2
XM ̅ )2
= ∑ W(M − M (40)
n′
2
XM ̅ )2
= ∑ W(M − M
n′
2
If the XM value calculated is lower than the corresponding one on Table 18 for (n’ – 1) degrees of
freedom, it is considered that there are no elements to suspect on the heterogeneity of potencies. In
this case, the average potency and the calculated limits are correct.
2
If the XM value is higher than the one on Table 18, it is considered that the potencies are
heterogeneous, that is, that the dispersion of individual M values is higher than expected, according
to the respective confidence limits. In this case, do not apply the formulas 37 and 39, investigate the
origin of this heterogeneity and, if considered adequate, calculate M̅ using semi-weights W’:
W ′ = 1/(V + v) (41)
where
L2
V = 1/W = (42)
4t 2
and v is the variance of heterogeneity between assays and calculated by the equation:
∑ M 2 − (∑ M)2 /n′ ∑ V
V= − (43)
n′ − 1 n′
When V varies in such a way that the v calculated is a negative number, it is possible to calculate an
approximate v, omitting the term after the minus sign on equation 43.
̅ = ∑ (W ′ M)/ ∑ W′
M (44)
n′ n′
M = ∑(W ′ M)/ ∑ W′
n′ n′
𝐿′2𝑐 = 4𝑡 2 / ∑ 𝑊′ (45)
where t, from Table 3, has degrees of freedom equal to the sum of degrees of freedom from the
variance of error from n’ individual assays.
In the special case of heparin assay, all logarithms of potency (M) have the same weight and the
confidence interval from log estimated potency M̅ is determined as follows:
L = 2st/√n′ (47)
where
Ms = M̅ + 1/2 L (48)
Mi = M̅ − 1/2 L (49)
Rs = antilog Ms (50)
Ri = antilog Mi (51)
STATISTICAL TABLES
Table 1 – Table G for atypical values.
n 3 4 5 6 7
G1 0.976 0.846 0.729 0.644 0.586
n 8 9 10 11 12 13
G2 0.780 0.725 0.678 0.678 0.605 0.578
n 14 15 16 16 18 19 20 21 22 23 24
G3 0.602 0.579 0.559 0.559 0.527 0.514 0.502 0.491 0.481 0.472 0.464
P 2 + A2 + ⋯ Z2 P2 + A2 + ⋯ Z2
Preparations h-1 −K −K
2𝑛 3𝑛
(LP + LA + ⋯ LZ )2 (LP + LA + ⋯ LZ )2
Regression 1 =E =E
2𝑛ℎ 2𝑛ℎ
(Q 𝑃 + 𝑄A + ⋯ Q Z )2
Quadratic 1 -- =Q
6𝑛ℎ
P2 ₁ + P2 ₂ + ⋯ Z2 d P2 ₁ + P2 ₂ + ⋯ Z2 d P2 ₁ + P2 ₂ + ⋯ Z2 d
Treatments k–1 −𝐾 −𝐾 −𝐾
𝑛 𝑛 𝑛
Blocks 𝐶 2 ₁ + C2 ₂ + ⋯ 𝐶 2 n
n–1 -- -- −K
(columns) 𝑘
By
Residual error * * *
difference
TOTAL N–1 ∑ y2 − K ∑ y2 − K ∑ y2 − K
__________
* Obtained by subtracting, from the total reduced sum of squares, all other reduced sums of squares calculated for the corresponding design.
Table 12 – t’ table for two-tailed comparison between (h-1) samples and one standard for a coefficient of
gl1 = (h-1) = number of samples (excluding standard)
gl2
1 2 3 4 5 6 7 8 9
5 2.57 3.03 3.29 3.48 3.62 3.73 3.82 3.90 3.97
6 2.45 2.86 3.10 3.26 3.39 3.49 3.57 3.64 3.71
7 2.36 2.75 2.97 3.12 3.24 3.33 3.41 3.47 3.53
8 2.31 2.67 2.88 3.02 3.13 3.22 3.29 3.35 3.41
9 2.26 2.61 2.81 2.95 3.05 3.14 3.20 3.26 3.32
10 2.23 2.57 2.76 2.89 2.99 3.07 3.14 3.19 3.24
11 2.20 2.53 2.72 2.84 2.94 3.02 3.08 3.14 3.19
12 2.18 2.50 2.68 2.81 2.90 2.98 3.04 3.09 3.14
13 2.16 2.48 2.65 2.78 2.87 2.94 3.00 3.06 3.10
14 2.14 2.46 2.63 2.75 2.84 2.91 2.97 3.02 3.07
15 2.13 2.44 2.61 2.73 2.82 2.89 2.95 3.00 3.04
16 2.12 2.42 2.59 2.71 2.80 2.87 2.92 2.97 3.02
17 2.11 2.41 2.58 2.69 2.78 2.85 2.90 2.95 3.00
18 2.10 2.40 2.56 2.68 2.76 2.83 2.89 2.94 2.98
19 2.09 2.39 2.55 2.66 2.75 2.81 2.87 2.92 2.96
20 2.09 2.38 2.54 2.65 2.73 2.80 2.86 2.90 2.95
24 2.06 2.35 2.51 2.61 2.70 2.76 2.81 2.86 2.90
30 2.04 2.32 2.47 2.58 2.66 2.72 2.77 2.82 2.86
40 2.02 2.29 2.44 2.54 2.62 2.68 2.73 2.77 2.81
60 2.00 2.27 2.41 2.51 2.58 2.64 2.69 2.73 2.77
120 1.98 2.24 2.38 2.47 2.55 2.60 2.65 2.69 2.73
∞ 1.96 2.21 2.35 2.44 2.51 2.57 2.61 2.65 2.69
L²P + L²A
Parallelism 1 −E
2𝑛
L²I + L²II
Phases X Regression 1 −E
2𝑛
Blocks – Parallelism –
Error I Difference
(Phases X Preparations) – (Phases X Regression)
B²I + B²2 + ⋯ + B²2𝑛
Blocks (animals) bl ̶ 1 −𝐾
2
𝑃2 + 𝐴2
Preparations 1 −K
2𝑛
(LP + LA )2
Regression 1 =E
𝑁
F²I + F²II
Phases 1 −K
2𝑛
TOTAL N–1 ∑ y2 − K
__________
K = (∑y)2/N
N = total number of responses
n = total number of replicas per dose including the two phases; bl = number of blocks (animals)
B = sum of the two responses for each block (animal)
Probits 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
1 0.001 0.001 0.001 0.002 0.002 0.003 0.005 0.006 0.008 0.011
2 0.015 0.019 0.025 0.031 0.040 0.050 0.062 0.076 0.092 0.110
3 0.131 0.154 0.180 0.208 0.238 0.269 0.302 0.336 0.370 0.405
4 0.439 0.471 0.503 0.532 0.558 0.581 0.601 0.616 0.627 0.634
5 0.637 0.634 0.627 0.616 0.601 0.581 0.558 0.532 0.503 0.471
6 0.439 0.405 0.370 0.336 0.302 0.269 0.238 0.208 0.180 0.154
7 0.131 0.110 0.092 0.076 0.062 0.050 0.040 0.031 0.025 0.019
8 0.015 0.011 0.008 0.006 0.005 0.003 0.002 0.002 0.001 0.001
Table 20 – Table of Analysis of variance for the simple linear regression model – 5 x 1 design.
Y = b0 + b1X ∑(x − x̅)(y − y̅)
∑(x − x̅)(y − y̅) 𝑟=
𝑏1 = (x − x̅)2 (y − y̅)2
∑(x − x̅)2 (N − 1)√ N − 1 √ N − 1
b0 = y̅ − b1 x̅
Source of
gl Sum of squares Average square F calculated
variation
Regression 1 SQreg = b1Σxy + b0Σy – (Σy)2/N QMreg = SQreg QMreg/QMres
(Σyi)2 = (y11 + y12 + y13 + ... + y19)2 + ... + (y51 + y52 + y53 + ... + y59)2
(x − x̅)2
√ = Sxx = standard deviation from variable (x)
N−1
(y − y̅)2
√ = Syy = standard deviation from variable response (y)
N−1
Direct fingerprint assay by the guinea pig cardiac arrest method The standard solution was used in
the concentration of 0.0658 IU/mL. An equivalent dilution of sample was prepared from the assumed
potency of SA = 1.3 IU/100 mg.
The guinea pigs were perfused randomly with standard or sample solution. The precise volume
necessary to produce cardiac arrest in each animal was registered.
From equation 1:
M’ = 1.3974 – 1.4089 = – 0.0115
From equation 6:
M = – 0.0115 + log 1.3 = 0.1024
From equation 5:
R = antilog 0.1024 = 1.2660
From equation 3:
1 19,56412 14,08902
𝑆²𝑥 = [(1,44042 + ⋯ + 1,33042 − ) + (1,53172 + ⋯ + 1,40722 − )]
22 14 10
1
𝑆²𝑥 = [27,3829 − 27,3396 + 19,8879 − 19,8500]
22
𝑆²𝑥 = 0,003691
From equation 2:
1 1
𝑆²𝑀 = 0,003691 ( + ) = 0,000632
14 10
𝑆𝑀 = √0,000632 = 0,0251
From equation 7:
𝑅𝑠
= 𝑎𝑛𝑡𝑖𝑙𝑜𝑔 [0,1024 ± (2,07 × 0,0251)]
𝑅𝑖
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.2-00
The average estimate of the potency from the fingerprint sample is 1.27 IU/100 mg.
The confidence limits (p=0.05) for the true potency are 1.12 IU/100 mg and 1.43 IU/100 mg.
Human chorionic gonadotropin assay by the method of increased weight of seminal vesicles
The doses used from standard were: p1 = 1.0 IU/mL, p2 = 2.0 IU/mL and p3 IU/mL. Equivalent doses
of the sample were prepared from the assumed potency SA = 3000 IU/mg. The rats were injected
subcutaneously with 0.20 mL of the respective solution, for three consecutive days, in a total of
0.6 mL/rat.
P1 P2 P3 a1 a2 a3
11.4 8.3 14.9 9.1 14.9 18.8
11.6 13.1 13.8 9.9 12.3 16.7
10.2 9.0 14.6 10.5 15.4 12.7
9.1 14.4 15.2 8.4 14.9 16.2
9.5 11.7 12.3 10.1 12.8 17.3
7.7 11.72* 15.5 10.1 10.0 12.8
__________
* missing value replaced by the average from the treatment.
N = 48
n=8
K = (∑y)2/N = 7 651.25
∑y2 = 8 031.21
287,422 + 318,62
Preparações = − 7651,25 = 20,26
24
(36,8 + 49,0)2
Regressão = = 230,05 = E
32
36,82 + 49,02
Paralelismo = − 230,05 = 4,65
16
[5,96 + (−15,6)]2
Quadrático = = 0,97 = Q
96
5,962 + (−15,6)2
Diferença de quadráticos = − 0,97 = 4,84
48
78,402 + 93,832 + ⋯ 128,102
Tratamentos = − 7651,25 = 160,77
8
Total = 8 031.21 – 7 651.25 = 379.95
Error = 379.95 – 260.77 = 119.18
Validity of assay:
Calculation of the estimated potency and confidence limits: Use formulas 10 to 15.
36,8 + 49,0
b= = 8,90
2 × 0,301 × 8 × 2
318,60
y𝐴 = = 13,27
24
287,42
y𝑃 = = 11,97
24
13,27 − 11,97
= = 0,1460
8,90
SA = 3 000 log SA = 3.4771
230,05
C= = 1,05
230,05 − 2,91(2,02)2
𝑀′𝑠
= 1,05 × 0,146 ± √(1,05 − 1)[1,05(0,146)2 + 8/3(0,3010)2
𝑀′𝑖
𝑀′𝑠 = 0,2679
𝑀′𝑖 = 0,0381
The doses used from standard were: p1 = 0.25 IU/mL, p2 = 0.50 IU/mL and p3 = 1.00 IU/mL.
Equivalent doses of the sample were prepared based on the assumed potency SA = 1 650 IU/mg. The
diameters of the zones of inhibition are available on Table 25.
N = 42
n=7
K = (Σ y)2 /N = 15101.26
Σ y2 = 15 535.96
397,82 + 398,62
Preparações = − 15101,2610 = 0,0152
21
(53,7 + 53,1)2
Regressão = = 407,3657 = E
28
53,72 + 53,12
Paralelismo = − 407,3657 = 0,0129
14
[−1,5 + (−1,9)]2
Quadrático = = 0,1376 = Q
84
−1,52 + (−1,9)2
Diferença de quadráticos = − 0,1376 = 0,0019
42
105,52 + 133,12 + ⋯ 159,12
Tratamentos = − 15101,261 = 407,53
7
123,92 + 113,72 + ⋯ 113,22
Blocos(Placas) = − 15101,261 = 22,18
6
Total = 15 535.96 – 15 101.261 = 434.7
Error = 434.7 – 22.18 – 407.53 = 4.99
Validity of assay
b) non-significant deviation from parallelism, F calculated 0.08 is lower than the critical value from
Table 4 for α= 0.05, gl1 = 1 and gl2 = 30, and
c) non-significant deviation from linearity, F calculated = 0.81 and 0.01.
53,7 + 53,1
b= = 12,67
28 × 0,301
398,6
y̅𝐴 = = 18,98
21
397,8
y̅𝑃 = = 18,94
21
18,92 − 18,94
M′ = = 0,003157
12,672
SA = 1650 IU/mg
407,3657
C= = 1,0017
[407,3657 – 0,17(2,04)2 ]
𝑀′𝑠 = 0,0235
𝑀′𝑖 = −0,0171
Assay of oxytocin – method of contraction of female rat’s isolated uterus: The administered doses of
standard were: p1 = 0.2 mL and p2 = 0.25 mL of solution wit 0.02 IU/mL. Equivalent doses of the
sample were prepared based on the assumed potency of 10 IU/mL diluted 1:500.
N = 16
n=4
K = (Σ y)2 /N = 6322/16 = 24 964
3082 + 3242
Preparações = − 124964,0 = 16,0
8
(24 + 24)2
Regressão = = 144,0 = E
2×4×2
242 + 242
Paralelismo = − 144,0 = 0
2×4
1422 + 1662 + 1502 + 1742
Tratamentos = − 24964 = 160
4
1522 + 1502 + 1612 + 1552
Filas = − 24964 = 31,5
4
1602 + 1562 + 1612 + 1552
Colunas = − 24964 = 6,5
4
Total = 25220 – 24964 = 256.0
The analysis did not present significant differences (p > 0.05) between rows and between columns.
Validity of assay
Calculation of the estimated potency and confidence limits: Use formulas 10 to 15.
24 + 24
b= = 61,91
0,0969 × 4 × 2
324
y̅𝐴 = = 61,91
8
308
y̅𝑃 = = 38,5
8
40,5 − 38,5
M′ = = 0,0323
61,91
SA = 10 log SA = 1
M = 0.0323 + 1 = 1.0323
144,0
C= = 1,67
144,0 − 9,67 × 2,452
c’ = 1, from Table 15
𝑀′𝑠
= 1,67 × 0,0323 ± √(1,67 − 1,0)[1,67(0,0323)2 + 1(0,09691)2 ]
𝑀′𝑖
𝑀′𝑠 = 0,1402
𝑀′𝑖 = 0,0324
Assay of insulin in mice. The doses used from standard were p1 = 60 mIU/mL and p2 = 120 mIU/mL.
Equivalent doses of the sample were prepared, a1 = 60 mIU/mL and 2 = 120 mIU/mL from the assumed
potency SA = 27.4 IU/mL. The mice were injected with 0.1 mL of the respective solution for each
10 g of average weight, according to Table 6.
Table 32 – Example 5: concentration of blood glucose (mg/100 mL), forty minutes after the injection.
Group 1 Group 2 Group 3 Group 4
p1 a2 total p1 a2 total p1 a2 total p1 a2 Total
37.1 16.6 53.7 32.4 32.4 80.8 36.8 17.0 53.8 30.9 52.1 83.0
35.2 40.1 75.3 35.2 35.2 103.0 53.2 24.9 78.1 27.8 59.4 87.2
43.1 33.9 77.0 35.3 35.3 108.4 71.2 58.2 129.4 35.4 39.1 74.5
41.3. 16.2 57.5 32.9 32.9 78.1 37.1 24.8 61.9 49.8 79.0 128.8
54.2 33.2 87.4 31.9 31.9 65.0 45.9 22.7 68.6 28.2 37.3 65.5
41.4 13.1 54.4 51.2 51.2 113.6 82.2 42.7 124.9 49.9 51.1 101.0
48.6 32.7 81.3 38.2 38.2 114.4 64.8 33.9 98.7 28.3 59.5 87.8
N = 96
n = 24
bl = 48
K = (∑y)2/N = 4 484.02/96 = 209 440.17
∑y2 = 237 201.30
448459,8
Blocks = − 209440,17 = 14789,73
2
2175,72 + 2308,32
Preparation = − 209440,17 = 183,15
48
2279,12 + 2204,92
Phase = − 209440,17 = 57,35
48
[(−426,7) + (−555,9)]2
Regression = = 10057,32 = E
96
(−426,7)2 + (−555,9)2
Paralelism = = 10057,32 = 173,88
48
(−465,1)2 + (−517,5)2
Phase × Regression = − 10057,32 = 28,60
48
Validity of assay:
The assay meets the validity conditions:
a) significant regression, F calculated 165.52 is higher than the critical value from Table 5, for α =
0.01, gl1 = 1 and gl2 = 44;
b) non-significant parallelism, F calculated 0.53 is lower than the critical value from Table 4, for α
= 0.05, gl1 = 1 and gl2 = 44.
c) None of the three interactions was significant – the F values calculated: 0.13, 0.09 and 0.00 were
lower than the critical value from Table 4 for α = 0.05, gl1 = 1 and gl2 = 44.
(−426,7) + (−555,9)
b= = −68,01
24 × 2 × 0,301
2175,7
y̅𝑃 = = 45,33
2 × 24
2308,3
y̅𝐴 = = 48,09
2308,3
48,09 − 45,33
M′ = = −0,0406
− 68,01
10057,32
C= = 1,025
[10057,32 − 60,76(2,01)2 ]
c’ = 1, from Table 15
𝑀′𝑠
= 1,025(−0,0406) ± √(1,025 − 1)[1,025(0,0406)2 + 1(0,301)2
𝑀′𝑖
𝑀′𝑠 = 0,0064
𝑀′𝑖 = −0,0064
Assay of heparin by the method of inhibition of coagulation of citrated sheep plasma: The doses used
of standard, in mL, were: p1 = 0.78; p2 = 0.76; p3 = 0.74; p4 = 0.72; p5 = 0.70; and p6 = 0.68. Equivalent
doses (a) of the sample were prepared from the assumed potency SA = 140.6 IU/mg. The assay was
developed as described in the heparin assessment method in this volume. Three assays were
conducted. As an example of calculation of M, only the assay number 1 will be developed.
Calculation of the estimated potency and confidence limits: Use formulas 27, 28 and 40 to 45.
xiP = 0.8691
xiP = 0.8572
x(i + 1) = 0.8691
y(i + 1) = 0.750
0,8572 − 0,8691
xP = 0,8691 + (0,4171 – 0,5) = 0,8661
0,417 − 0,750
xiA = 0.8807
yiA = 0.333
x(i + 1)A = 0.8691
y(i + 1)A = 0.667
8691 − 0,8807
X A = 0,8807 + (0,333 – 0,5) = 0,8749
0,333 − 0,667
SA = 140.6 IU/mg
M1 = 0.8661 – 0.8749 + log 140.6 = 2.1392
Assuming that the other two assays conducted with the same sample provided the estimates:
M2 = 2.1995 and M3 = 2.1805, calculate 𝑀̅
̅ = (2.1392 + 2.1995 + 2.1805)/3 = 2.1731
𝑀
̅ = 149.0 IU/mg = (2.1392+2.1995+2.1805)/3 = 2.1731 = antilog M = 149.0 IU/mg
R = anti log 𝑀
Standard P Sample A
Log dose Averages log Averages log dose Averages log Averages
Tube (mL × 10) dose degree of (mL × 10) dose degree of
xP xiP coagulation xA xiA coagulation
YiP yiA
5 0.8450 0.8450 0.917 0.8451 0.8450 1.000
6 - - - 0.8325 - -
Example 7: microbiological assay with five doses of standard and one dose of sample (5 x 1).
Totals:
N = 45
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.2-00
∑ x = − 9,983205
∑ y = 896,936
∑ y 2 = 19.076,73
∑ xy = − 100,374
∑(x − 𝑥̅ )²
√ = 0,4305
𝑁−1
∑(y − 𝑦̅)²
√ = 5,2203
𝑁−1
b0 = 22.61426
b1 = 12.09086
A1 P3 A2 P3 A3 P3
Σyi2 = Σyi2 = Σyi2 =
Σyi2 =30,986.56 Σyi2 =30,324.74 Σyi2 = 30,516.6
31,176.96 30,150.85 29,780.40
∑ X2 = 0.024058
∑ (Tx2/9) = 0.001377
t = 2.042
k’ = 9
f=9
n = 32
0,024058 − 0,001377
2
𝑆𝑀 = = 0,00071 (fórmula 19)
32
s = 0.02662
½ L = 0.01812 (formula 20)
Table 42 – Example 7: log potency ratio and confidence limits for samples A 1, A2, A3 and A4.
A1 A2 A3 A4
Logarithm of
potency ratio 0.004963 - 0.00505 0.009833 - 0.00248
(log)
M’AS and M’AI 0.02308 - 0.1316 0.01307 0.01564 0.01564 0.02795 0.01564 - 0.02060
Calculation of estimated potency and confidence limits for sample A1: Using formulas 17 and 20 to
25.
M’ (A1) = ∑ X1/9 = 0.004963
M = M’ + log 600,000 = 5.78311
R = anti log 5.78311 = 606,895.97 IU/vial
M’as (A1) + ½ L = 0.004963 + 0.01812 = 0.02308
M’Ai (A1) – ½L = 0.004963 – 0.01812 = -0.01316
Regression Equation
Assay of insulin by the method of convulsion in mice: The doses used from standard were p1 = 18
mIU/mouse and p2 = 30 mIU/mouse. Equivalent doses of the sample (a1 = 18 mIU/mouse and a2 =
mIU/mouse) were prepared based on the assumed potency SA = 40 IU/ mL.
The mice, divided randomly into four groups, were submitted to subcutaneous injection with
0.25 mL/mouse of the respective solution.
(P + A)2 20,152
K= = = 101,5056
k 4
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.2-00
9,752 + 10,42
Preparations = − 101,5056 = 0,1056
2
(0,79 + 0,94)2
Regression = = 0,7482 = E
4
0,792 + 0,942
Paralelism = − 0,748 = 0,0056
2
𝑘 4
𝑠2 = = 0,0616
∑ 𝑤𝑛 30(0,576) + 28(0,619) + 28(0,619) + 24(0,540)
Calculation of the estimated potency and confidence limits: Use formulas 10 to 15.
I = log 30 – log 18 = 1.4771 – 1.2553 = 0.2219
t = 1.96 with gl = infinite and p = 0.05 (from Table 3)
0,79 + 0,94
b= = 3,9318
2(0,2219)
9,75
y̅𝑃 = = 4,87
2
10,4
y̅𝐴 = = 5,20
2
5,20 − 4,87
M′ = = 0,0839
3,9318
𝑀′𝑠
= 1,4625 × 0,0839 ± √0,4625[1,425(0,0839)2 + (0,2219)2 ]
𝑀′𝑖
𝑀′𝑠
= 0,1227 ± 0,1658
𝑀′𝑖
𝑀′𝑠 = 0,2885
𝑀′𝑖 = −0,0431
Σ 𝑀𝑊 2058,6174
̅=
𝑀 = = 13966
Σ𝑊 1474,0148
Since X2 calculated is lower than the critical value, there are no elements to suspect of heterogeneity.
𝑀′𝑠
̅ ± 1,98 × 0,0260
=𝑀
𝑀′𝑖
Ms = 1.4226
Mi = 1.3700
Rs = 26.5
Ri = 23.5
8.3 RADIOPHARMACEUTICALS
14B
GLOSSARY
Radioactivity of the radionuclide related to the unit mass of the element or compound. It is commonly
referred to the activity of 1 g of the substance specified on the monograph:
N × 0,693
S= desintegrations/s/g
W ou M × T1/2
where
S = specific radioactivity;
N = Avogadro’s number;
W = atomic mass;
M = molecular mass.
Carrier
Stable isotope of the radionuclide in question, added to the radioactive preparation in the chemical
form identical to the one where the radionuclide is present.
Preparation or set of reagents that must be reconstituted or combined with a radionuclide for the
synthesis of the final radiopharmaceutical, before administration to the patient. They may come in
the form of lyophilized reagents or other substances and are most commonly known as labeling kits.
Radioactive concentration
The radioactive concentration of the solution is the radioactivity of the radionuclide contained in the
unit volume and usually referred to as activity per milliliter. As it occurs with all specifications
involving radionuclides, it is necessary to state the date and, in the case of radionuclides with short
half-life, the time when the radioactive concentration was determined.
Radioactive decay
The nuclei from radioactive elements (radionuclides) suffer loss of particles and/or energy according
to their own characteristics. These characteristics include the speed of decay and the type of emission.
The emission of particles by the nuclei determines the modification of their mass number. When the
particle emitted has positive or negative charge, the nucleus suffers a change in the atomic number
and, consequently, in the number of electrons in the electron cloud of the atom corresponding to it,
determining a change in the chemical properties of the atom. The radioactivity decays in exponential
ratio, which is characteristic for each radionuclide. The activity at any time can be calculated by the
expression:
𝐴 = 𝐴0 𝑒 −𝜆𝑡
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.3-00
where
A = activity on t time;
A0 = initial time;
λ = decay constant – also named disintegration constant or transformation constant, that is, the
fraction of radioactive atoms that suffer transformation in the time unit, provided this time is short
when compared to the physical half-life;
t = time elapsed;
e = base from Napierian logarithms.
Disintegration
Generator
System that incorporates a parent radionuclide that, by decay, produces a daughter radionuclide that
can be removed by elution or by any other method to be used as an integral part of a
radiopharmaceutical.
Isotopes
Nuclides from a same chemical element which nuclei have the same atomic number and different
atomic mass.
Starting material
Effective half-life
The time it takes for a radionuclide in an organism to halve its activity as a combined result of
biological elimination and radioactive decay. The effective half-life is important for calculating the
optimal dose of the radiopharmaceutical to be administered and for monitoring the quantity of
radiation exposure. It can be calculated from the formula:
𝑇1/2𝑝 × 𝑇1/2𝑏
𝑇1/2𝑒 =
𝑇1/2𝑝 + 𝑇1/2𝑏
where
T1/2e = time of effective half-life of the radiopharmaceutical;
T1/2p = time of physical half-life of the radionuclide;
T1/2b = time of effective half-life of the radiopharmaceutical;
Physical half-life
Time necessary for half a population of atoms from a radionuclide to decay to another nuclear form.
The half-life is related to the decay constant (λ) by the equation:
0,693
𝑇1/2 =
λ
Neutrino
Particle difficult to detect, with negligible mass, but with energy emitted simultaneously to the
emission of beta particle. The sum of energies from the beta particle and the neutrino corresponds to
a value quantified for each beta disintegration process.
Nuclides
Species of atoms characterized by the constitution of their nuclei, particularly by their number of
protons and electrons, and also by their nuclear energy state.
Usually, these precursors are not produced in large scale. Some precursors are synthesized by the
radiopharmaceuticals production laboratory, others are supplied by specialized producer laboratories.
Tests for identity, chemical purity and assay must be conducted through validated procedures. When
batches of precursors are accepting using the certificates of analysis, adequate evidence must be
established to demonstrate the reliability of the supplier and at least one identity test must be
conducted. It is recommended to test precursor materials before their use in the radiopharmaceutical
production routine, to ensure that, under specified production conditions, the precursor allows the
preparation of the radiopharmaceutical in the amount and quality specified.
Expiry date
Limit date specified by the manufacturer for the use of a radiopharmaceutical, before and after the
reconstitution and/or radioactive labeling of the product, taking into account chemical, radiochemical
and radionuclidic degradation products, maintaining the established conditions of storage and
transportation.
Chemical purity
Percentage ratio of the molecule mass from the compound of interest in its chemical state indicated,
in relation to the total mass of the preparation. The relevant chemical impurities and corresponding
limits are listed in the individual monographs.
Radionuclidic purity
It is the ratio, expressed in percentage, of the radioactivity of the radionuclide in relation to the total
radioactivity of the radiopharmaceutical. The relevant radionuclidic impurities are listed, with their
limits, in the individual monographs.
Radiochemical purity
Percentage ratio of radioactivity of the radionuclide of interest in its chemical state indicated, in
relation to the total radioactivity of the radiopharmaceutical preparation. The relevant radiochemical
impurities are listed, with their limits, in the individual monographs.
Specific radioactivity
Expresses the radioactivity of a radionuclide per unit of mass of the element or chemical product of
interest.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.3-00
Total radioactivity
Expresses the radioactivity of the nuclide expressed by unit (vial, capsule, ampoule, generator, etc.).
Radioisotopes
Radioactive isotopes or radionuclides. They are unstable isotopes that suffer radioactive decay and
turn into a new element. These are atoms that disintegrate by emission of corpuscular (particle) or
electromagnetic radiation. Every radioisotope is characterized by its half-life time (T1/2), expressed
in time units (seconds, minutes, hours, days and years) and by the nature and energy of its radiation.
The energy can be expressed in electron volts (eV), kilo-electron volts (keV) or mega-electron volts
(MeV).
INTRODUCTION
The production of radiopharmaceuticals must meet the requirements from Good Manufacturing
Practices (GMP) for Radiopharmaceuticals, and also comply with pharmacopoeial specifications.
Radiopharmaceuticals have their production, supply, storage, use and disposal regulated by the
current national legislation.
The radiopharmaceutical has the radionuclide in one of the following forms: as an atomic or
molecular element, an ion, or included or bonded to organic molecules, by chelation process or by
covalent bond.
STORAGE
STABILITY
The preparations of radiopharmaceuticals tend to be less stable than their corresponding inactive
materials, their decomposition occurs by radiolysis and, therefore, they must be used within a short
period. The effects of primary radiation include the disintegration of the radioactive atom and the
decomposition of molecules when the fraction of energy from particle emitted or from gamma ray is
absorbed by these molecules.
The stability of radiopharmaceuticals depends on many factors, including the energy and nature of
the radiation, the specific activity and the storage time. The effects of primary radiation may induce
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.3-00
secondary effects due to the formation of excited species, which may degrade other molecules, such
as the ones from solvents or preservatives, for example.
The susceptibility to oxidation and reduction of a small amount of chemical species present must also
be considered. The initial exclusion of all traces of oxidation and reduction agents is occasionally not
enough, because such agents may be continuously produced due to effects of radiation. During
storage, containers and solution may turn dark due to the radioactivity emitted. Such factor does not
necessarily indicate deterioration of the preparation.
PRESERVATIVES
Injectable radiopharmaceutical preparations with a shelf life period larger than one day and that do
not have an antimicrobial preservative must be provided in single-dose vials. However, if the
preparation is provided in a multi-dose container, it must be used within 24 hours after the first dose
is taken, aseptically.
Injectable radiopharmaceutical preparations in which the shelf life period is larger than one day and
that have antimicrobial preservative can be provided in multi-dose containers. After the first dose is
taken, aseptically, the container must be stored at temperature from 2 °C to 8 °C and the contents,
used within seven days.
DILUTION
If dilution is necessary, it is preferable to use vehicles with the same composition as the ones present
in the preparation. In case of injectable radiopharmaceuticals, sterile solutions and materials, free
from particles and traces of organic matter, must be used.
The amount of radioactive material present in the preparation is frequently very small to be measured
by the chemical or physical methods available.
where
Smax = maximum specific activity,
W = atomic mass,
T1/2 = half-life time in hours.
It is verified that, for example, for the sodium pertechnetate (99mTc) solution with radioactive
concentration of 37 MBq (1 mCi) per mL, the concentration of pertechnetate can be as low as 3 x 10-
10
g/mL. The behavior of such small masses in very diluted solutions may require the addition of an
inert carrier to limit the adsorption to the surface of the container, as well as facilitate the chemical
reactions for preparation of radiopharmaceuticals.
BIOLOGICAL CONTROL
Sterility (5.5.3.2.1)
The limit of bacterial endotoxins is indicated in the monographs on radiopharmaceuticals. The test
validation is necessary to exclude any interference due to the nature of the radiopharmaceutical.
Radioactivity levels must be standardized, since some types of radiation and radionuclides, especially
high levels of activity, may interfere with the test. The pH of some radiopharmaceutical preparations
must be adjusted to pH 6.5 – 7.5 to promote optimal results.
RADIOACTIVITY
Property that certain nuclides have to emit radiation by spontaneous transformations of their nuclides.
In general, the term “radioactivity” is used to describe the phenomenon of radioactive decay and to
express the physical amount (activity) of this phenomenon. The activity of a preparation is the number
of nuclear transformations per time unit that occur in the preparation. These transformations can
involve the emission of charged particles, capture of electrons or isomeric transition. The charged
particles emitted by the nucleus can be alpha particles (helium nuclei, with mass number 4) or beta
particles (negative or positive charge electrons, respectively -1β – negatron or +1β – positron). The
emission of beta particles is accompanied by the emission of neutrino.
The emission of charged particles can be accompanied of gamma rays, which are also emitted in the
isomeric transition process. This emission of gamma rays can be partially replaced with the ejection
of electrons, known as internal conversion electrons. This phenomenon, just like the electron capture
process, causes secondary emission of X-rays, due to the reorganization of electrons in the atom. This
secondary emission also causes the ejection of low-energy electrons known as Auger electrons. X-
rays, eventually accompanied of gamma rays, are emitted in the electron capture process. +1β
particles are annihilated in contact with another electron (-1e) present in the matter, and this process
is followed by the emission of two gamma photons, each one with energy of 511 keV, usually emitted
180° from each other and which is named annihilation radiation.
The penetrating power of each radiation varies considerably according to its nature and energy. Alpha
particles are completely absorbed by thicknesses of solids or liquids that vary from a few to dozens
of micrometers; beta particles are completely absorbed in the thickness of some millimeters to several
centimeters. Gamma rays are not completely absorbed, but only attenuated, and a ten-fold reduction
may require, for example, a few centimeters of lead. The denser the absorbent, the lower is the reach
of alpha and beta particles and the higher the attenuation of gamma rays is.
Radioactivity measurement
The absolute measurement of a sample radioactivity can be made if the decay scheme of the nuclide
is known, but, in practice, many corrections are required to obtain accurate results. For this reason, it
is common to take measurements using a primary standard source.
Primary standards may not exist for radionuclides with short half-life, such as, for example, positron
emitters. The measurement instruments are calibrated using appropriate standards for particle emitter
radionuclides.
The Geiger-Müller counter can be used to measure beta and beta-gamma emitters. Scintillation
counters, semiconductors or ionization chambers can be used to measure gamma rays. Low-energy
beta emitters need a liquid scintillation counter.
In this case, the sample is dissolved in the solution of one or more (generally two) fluorescent organic
substances (primary and secondary scintillators), which convert part of the disintegration energy into
light photons, which are detected and converted into electric impulses in the photomultiplier. When
the liquid scintillation counter is used, comparative measurements must be corrected due to the effects
from light interference. Direct measurements must be taken in conditions that ensure that the
geometric conditions are constant (identical volumes of containers and solutions).
Whatever the equipment used, it is essential to work in extremely well defined geometric conditions,
so that the radioactive source is always on the same position in the device and, consequently, its
distance from the measurement device is constant and remains the same, while the sample is
substituted with the standard.
All reactivity measurements must be corrected by subtraction of the background radiation activity,
due to the radioactivity of the medium and the spurious signals generated in the device itself. In
certain devices, where the count is performed in high levels of activity, the correction may be
necessary because of losses by coincidence, due to the resolution time of the detector and the
electronic equipment associated.
For the counting system with fixed dead time (τ), after each count the correction is given by the
equation:
N0
N=
1 − N0τ
where
N = actual counting rate per second;
N0 = counting rate measured per second;
In certain devices, the correction is made automatically. Corrections of coincidence loss must be made
before the corrections for background radiation. In the determinations of radioactivity, there are
statistical variations because they are related to the probability of nuclear disintegration. A sufficient
number of counts must be made to compensate for variations in the number of disintegrations per
time unit. At least 10,000 counts are necessary to obtain a standard deviation of no more than 1%.
The activity decays in exponential ratio, which is characteristic to each radionuclide. Its determination
is only true in the reference time specified. The activity in other times can be calculated from
exponential equation or by decay table, or also be obtained graphically from the curve established for
each radionuclide. All determinations of activity must be accompanied by statement of date and, if
necessary, the time when the measurements were made. The measure of activity from sample in
solution is calculated in relation to its original volume and expressed by unit of volume – radioactive
concentration.
Radioactivity units
In the International System (SI), the radioactivity is expressed in becquerel (Bq), which means one
transformation per second. The historical unit of activity is curie (Ci), equivalent to 3.7 x 1010 Bq.
The conversion factors between becquerel and curie and their submultiples are indicated on Table 1.
Table 1 – Radioactivity units used in radiopharmacy and the conversions between SI units and historical units.
Number of atoms transformed per
SI unit: becquerel (Bq) Historical unit: curie (Ci)
second
1 1 Bq 27 picocurie (pCi)
1000 1 kilobecquerel (Kbq) 27 nanocurie (nCi)
1 x 106 1 megabecquerel (MBq) 27 microcurie (µCi)
1 x 109 1 gigabecquerel (GBq) 27 millicurie (mCi)
37 37 Bq 1 (nCi)
37,000 37 KBq 1 (µCi)
3.7 x 107 37 MBq 1 (mCi)
3.7 x 1010 37 GBq 1 Ci
Identification of radionuclides
The radionuclide is usually identified by the physical half-life, by the nature and energy of its
radiation (or radiations), or by both.
Determination of half-life
The half-life is measured with the help of detection devices such as ionization chamber, Geiger-
Müller counter, scintillation counter, or semiconductor detector. The amount of activity, considering
the experimental conditions, must be sufficiently high to allow detection during several presumable
half-lives, but not too high, to avoid the phenomenon of coincidence loss due to, for example, the
equipment dead time.
The radioactive source is prepared in order to avoid losses during its handling. Liquid samples must
be contained in sealed vials or tubes. Solid products must be protected by a layer of cellulose acetate
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.3-00
adhesive sheet, or another material which mass per unit of area is negligible to avoid the attenuation
of significant amount of radiation in study. The same source is measured in identical geometric
conditions and at intervals that usually correspond to half of the half-life and by the time
corresponding to approximately three half-lives. The correct equipment operation is verified through
the use of a permanent source and the count variations are corrected, if necessary, as described in
To make the radioactivity measurement, a curve is traced by launching the time on the abscissa axis
and the logarithm of the number of counts per time unit, or the electric current, according to the type
of equipment used, in the ordinate axis. The half-life calculated from this curve must meet the
specification described in the respective monograph.
The nature and energy of the radiation emitted can be determined by several procedures that include
outlining the attenuation curve and using spectrometry. The attenuation curve is generally used for
determining the energy from beta radiation, and spectrometry is mainly used for determining the
energy from gamma radiation.
The attenuation curve is developed for pure beta emitters or for beta-gamma emitters when there is
no availability of gamma ray spectrometer. This method for determination of maximum energy from
beta radiation provides only approximate values.
The source, assembled conveniently to provide constant geometric conditions, is placed in front of
the thin window of the Geiger-Müller counter and protected as described on Determination of half-
life.
The source count is then measured. No less than six aluminum absorbers, with increasing mass per
area unit, are placed between the source and the counter, until the counter rate is not affected by the
addition of more absorbers. The absorbers are inserted in such a way that the geometric conditions
are maintained constant.
A curve is built by putting in abscissas the mass per unit of area from the absorber expressed in mg
cm-2 and, in ordinates, the logarithm of the number of counts per time unit for each of the absorbers
used. An identical curve is developed using the standard. The mass attenuation coefficient is
calculated in relation to the median, practically straight, part of the curves.
The mass attenuation coefficient, expressed in cm2 mg-1, depends on the energy from beta emission
and on the chemical and physical properties of the absorber. This allows the identification of beta
emission and the coefficient is calculated, from curves built as described previously, by the
expression:
2,303
µm = = (𝑙𝑜𝑔𝐴2 − 𝑙𝑜𝑔𝐴2 )
𝑚2 − 𝑚1
where
m1 = mass per area unit from the lighter absorber;
m2 = mass per area unit of the heavier absorber (measure m1 and m2 within the straight part of the
curve);
A1 = count rate for mass per area unit m1;
A2 = count rate for mass per area unit m2.
The attenuation coefficient thus calculated must not differ by more than 10% from the coefficient
obtained in identical conditions with the standard from the same radionuclide.
Gamma spectrometry is used to identify radionuclides by the energy and intensity of X or gamma
rays. It is based on the property that certain substances (scintillators) have of emitting light when they
interact with electromagnetic radiation. The number of photons produced is proportional to the energy
absorbed by the scintillator. The light is turned into electric impulses of amplitude approximately
proportional to the energy dissipated by gamma photons.
With the analysis of output pulses by percentage, the spectrum of energy from the source is obtained,
with the help of pulse analyzer. In the gamma ray scintillation spectra, there is one or more
characteristic peaks corresponding to the energies from gamma radiation in the source. These peaks
are accompanied by others, more or less large, due to secondary effects from the radiation in the
scintillator or the material around it. The shape of the spectrum varies according to the equipment
used, and it is necessary to calibrate it with the help of standard of the radionuclide in question.
The gamma ray spectrum from the radionuclide that emits the rays is from the own radionuclide, and
is characterized by the number of gamma rays with individualized energy produced by
transformation. This property can be used to identify which radionuclides are present in the source
and the amounts of each of them. It also allows to assess the degree of impurities present, by detection
of peaks foreign to the ones expected.
The preferred detector for the gamma ray spectrometry is a germanium semiconductor detector
activated with lithium. Sodium iodide scintillation detectors activated with thallium, although they
present lower resolution, can also be used. The output from each of these detectors occurs in the form
of electric pulses, which amplitude is proportional to the energy from gamma rays detected. After the
amplification, these pulses are analyzed in multichannel analyzer, which provides the gamma ray
spectrum from the source. The relation between gamma energy and the channel number can be easily
established using gamma ray sources with known energy. The detection system must be calibrated,
because the detector efficiency is a function of the gamma radiation energy, the source shape, and the
distance from source to detector. The detection efficiency can be measured with the help of the
calibrated source of the radionuclide in question or, for a more generic work, an efficiency curve
versus gamma radiation can be built from a series of calibrated sources of several radionuclides.
Using a low-resolution detector may bring some difficulty to identify impurities, because the peaks
on the spectrum may not be well resolved. In this case, it is recommendable to determine the half-life
by repeated measurements of sample.
If radioactive impurity with different half-life is present in a source, it is easily detectable by the
identification of characteristic peaks, which amplitudes decrease in different rates from the ones of
the radionuclide expected. The determination of half-life from interfering peaks by repeated sample
measurements will help identify the impurity. It is possible to establish the radioactivity decay rate
using gamma spectrometry, provided that the peaks decrease in amplitude due to the half-life.
RADIONUCLIDIC PURITY
To establish the radionuclidic purity of the preparation, the radioactivity and the identity of each
radionuclide present must be known. The most commonly used method to examine the radionuclidic
purity is the gamma spectrometry. It is not an entirely precise method because alpha-emitter and beta-
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.3-00
emitter impurities are usually not detectable, and when sodium iodide detectors are used the peaks
due to impurities are frequently hidden by the spectrum of the main radionuclide.
This monograph establishes the overall requirements for radionuclidic purity (for example, the
spectrum of gamma rays must not be significantly different from the one of the standard source) and
may establish limits for specific radionuclidic impurities (for example, molybdenum-99 in
technetium-99). These requirements are necessary, although they are not sufficient by themselves to
ensure that the radionuclidic purity of the preparation is adequate for human use. The manufacturer
must analyze its products, especially preparations of radionuclides with short half-life, for the
presence of impurities with long half-life, after a convenient period of decay. This way, information
can be obtained about the suitability of manufacturing processes and the control procedures.
Due to differences in the half-lives from different radionuclides present in the pharmaceutical
preparation, the radionuclidic purity changes with time. The specification of radionuclidic purity must
be ensured throughout the validity period. Sometimes, it is difficult to conduct this test before clearing
a batch produced for use, when the half-life of the radionuclide in the preparation is short. In this
case, the test is comprised of a production quality control.
RADIOCHEMICAL PURITY
The determination of radiochemical purity requires the separation of different chemical substances
that have the radionuclide and the estimated percentage of radioactivity associated to the chemical
substance stated.
Analytical methods of separation can be used in the determination of radiochemical purity, such as
chromatographic methods (paper, thin layer, molecular exclusion, gas chromatography or high-
performance liquid chromatography), electrophoresis and extraction by solvents.
Considering the very small masses of the radioactive material applied to chromatograms, the use of
carriers is sometimes necessary and they can be added when prescribed by the monograph.
After developing the paper or thin layer chromatography, the support is dried and the positions of the
radioactive areas are detected or by autoradiography or by measuring the radioactivity along the
chromatogram, with the help of counters duly collimated, or by cutting the strips and counting each
portion.
The positions of stains or areas allow chemical identification by comparison with solutions of the
same chemical (non-radioactive) substances, viewed by color reaction or examination under
ultraviolet light. Viewing by the direct color reaction from the radioactive sample is not always
possible or desirable, since the revelation may cause diffusion of the radioactive substance beyond
the stains or areas identified.
Since the radiochemical purity can change over time, especially due to decomposition by radiation,
the test result must indicate that the product presents values specified throughout the validity period
of the radiopharmaceutical.
SPECIFIC ACTIVITY
The specific activity is calculated by relating the radioactive concentration (radioactivity per volume
unit) with the concentration of the chemical substance being analyzed, after verification that the
radioactivity is only due to the radionuclide (radionuclidic purity) and the chemical species
(radiochemical purity) in question.
The specific activity changes over time, and must be expressed having as reference the date and, if
necessary, the time. The specification must be ensured throughout the validity period of the
radiopharmaceutical.
Table 2 – Information about the physical characteristics of radionuclides of relevance in the production of radiopharmaceuticals.
Internally
Energy Probability of Energy from photon Photons emitted
Radionuclide Physical half-life Type of decay Converted
(MeV) transition (%) (MeV) (%)
Transitions (%)
Cesium-137 30.1 y β+ 0.512 94.6 Via 2.6 min 137mBa 85.1 9.5
1.174 5.4 0.662 8 (Ba K X-ray)
0.032-0.038
Carbon-11 1223.1 s β+ 0.960 99.76 0.511 Coming from
annihilation
Carbon-14 5730 y Β- 0.158 100 - -
Chromium-51 27.7 d c.e. 100 0.320 9.83
0.005-0.006 ~22 (V K X-ray)
Cobalt-57 270 d c.e. 100 0.114 9.4
0.122 85.2
0.136 11.1
0.570 0.02
0.692 0.16
others low intensity
0.006-0.007 ~55% (Fe K X-ray)
Cobalt-58 70.8 d β+ 0.475 15.0 0.511 P+
c.e. 85 0.811 99.4
0.864 0.7
1.675 0.5
0.006-0.007 ~26 (Fe K X-ray)
Cobalt-60 5.27 y β- 0.318 99.9 1.173 99.86 0.02
1491 0.1 1.333 99.98 0.01
others <0.01
Dysprosium-165 2.32 h β+, γ 0.205 0.1 0.046 2.5
0.290 1.6 0.047 4.6
1.190 14.6 0.053 1.8
1.285 83.4 0.094 3.5
0.279 0.5
0.361 0.8
0.545 0.16
Erbium-169 9.4 d β+, γ 0.341 45 0.008 0.15
Table 2 (continued)
Energy from
Energy Probability of transition Photons emitted Internally Converted
Radionuclide Physical half-life Type of decay photon
(MeV) (%) (%) Transitions (%)
(MeV)
0.350 55
Fluorine-18 111 min β+, K 0.649 97 0.511 Coming from
annihilation
Gallium-67 78.3 h c.e. 100 0.091 3.6 0.3
0.185 23.5 0.4
0.209 2.6 0.02
0.300 16.7 0.06
0.394 4.4 0.01
0.494 0.1
0.704 0.02
0.795 0.06
0.888 0.17
0.008-0.010 43 (Zn X-ray)
via 9.2 µs 67mZn
0.093 37.6 32.4
0.008-0.010 13 (Zn X-ray)
Holmium-166 27.3 h β+, γ 0.191 0.2 0.007 7.6
0.394 1 0.048 2.8
1.773 48 0.049 5.0
1854 51 0.055 2.0
0.080 6.2
1.379 0.9
1.581 0.18
0.12
1.662
Indium-111 2.81 d c.e. 100 0.172 89.6 10.4
0.247 94 6
Indium-113 m 99.5 min t.i. 100 0.392 64.9 35.1
0.024-0.028 24 (in K X-ray)
Iodine-123 13.2 h c.e. 100 0.159 83.0 16.3
0.347 0.10
0.440 0.35
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.3-00
Table 2 (continued)
Energy from
Energy Probability of transition Photons emitted Internally Converted
Radionuclide Physical half-life Type of decay photon
(MeV) (%) (%) Transitions (%)
(MeV)
0.506 0.26
0.529 1.05
0.539 0.27
0.027-0.032 ~86 (Te K X-ray)
Iodine-124 4.1 d β+, γ, K 1.53 0.511 and Coming from
annihilation
2.13 0.605 66
0.644 12
0.730 14
1.320 1.0
1.510 4.2
1.695 14
2.09 2.0
2.26 1.5
Iodine-125 60.0 d c.e. 100 0.035 7 93
0.027-0.032 138 (Te K X-ray)
Iodine-131 8.06 d β- 0.247 1.8 0.080 2.4 3.8
0.304 0.6 0.284 5.9 0.3
0.334 7.2 0.364 81.9 1.7
0.606 89.7 0.637 7.2
0.806 0.7 0.723 1.8
1.3% of 131I decay via 12d
131m
Xe
100
(Xenon-131m) t.i. (percentage related to the 0.164 2 98
disintegration of 131mXe)
Iron-59 44.6 d β- 0.084 0.1 0.143 0.8
0.132 1.1 0.192 2.8
0.274 45.8 0.335 0.3
0.467 52.7 0.383 0.02
1.566 0.3 1.099 55.8
1.292 43.8
Table 2 (continued)
Energy from
Energy Probability of transition Photons emitted Internally Converted
Radionuclide Physical half-life Type of decay photon
(MeV) (%) (%) Transitions (%)
(MeV)
1.482 0.06
Krypton-81m 13 s γ - - 0.193 82
Lutetium-177 6.71 d β-, γ 0.175 12.3 0.071 0.16
0.384 9.0 0.113 6.3
0.497 78.7 0.208 11.0
0.250 0.2
Molybdenum-99 66.2 h β- 0.454 18.3 0.041 1.2 4.8
0.866 1.4 0.141 5.4 0.7
1.232 80 0.181 6.6 1.0
others 0.3 0.366 1.4
0.412 0.02
0.529 0.05
0.621 0.02
0.740 13.6
0.778 4.7
0.823 0.13
0.961 0.1
Table 2 (continued)
Energy from
Energy Probability of transition Photons emitted Internally Converted
Radionuclide Physical half-life Type of decay photon
(MeV) (%) (%) Transitions (%)
(MeV)
Rhenium-188 18 h β-, γ 1.964 25.3 0.155 14.9
2.119 71.4 0.477 1.0
0.633 1.2
0.635 0.14
0.673 0.11
0.829 0.41
0.931 0.56
1.13 0.7
1.306 0.01
Rubidium-81 4.7 h β+, γ, K 0.33 0.253
0.58 0.450
daughter 81mKr 1.05 1.10
Samarium-153 47 h β-, γ 0.26 0.1 0.0058 11.8
0.632 34.1 0.0409 17.2
0.702 44.1 0.0415 31.2
0.81 21 0.0470 12.2
0.0696 5.1
0.103 28.3
0.422 0.2
Selenium-75 118.5 d c.e. 100 0.066 1.1
0.097 2.9
0.121 15.7
0.136 54
0.199 1.5
0.265 56.9
0.280 18.5
0.401 11.7
others <0.05 each ~50 (as K
0.010-0.012 X-ray)
Table 2 (continued)
Energy from
Energy Probability of transition Photons emitted Internally Converted
Radionuclide Physical half-life Type of decay photon
(MeV) (%) (%) Transitions (%)
(MeV)
0.280 5.4
0.304 1.2 0.1
0.010-0.012 ~2.6
(as K X-ray)
Strontium-89 50.5 d β-, (γ) 0.582 0.01 0.909 0.01
1.491 99.98
Technetium-99m 6.02 h t.i. 100 0.002 ~0 99.1
0.141 88.5 10.6
0.143 0.03 0.87
daughter 99Tc
Table 2 (conclusion)
Physical half- Energy Probability of Energy from photon Photons emitted Internally Converted
Radionuclide Type of decay
life (MeV) transition (%) (MeV) (%) Transitions (%)
Thallium-201 73.5 h c.e. 100 0.031 0.29 10.1
0.032 0.25 9.6
0.135 2.9 8.9
0.166 0.13 0.2
0.167 8.81 16
Aluminum-113 115 d c.e. 100 0.255 21 0.1
0.024-0.028 73 (in K X-ray)
daughter 131mIn
3
Tritium ( H) 12.35 to 1.393 β- 0.0186 100
Tungsten-188 69.5 d β- 0.3 0.227
0.291
daughters
188m 188
+ Re
Xenon-131m 11.9 d t.i. 100 0.164 2 98
0.029-0.035 ~52 (Xe K X-ray)
Xenon-133 5.25 d β- 0.266 0.9 0.080 0.4 0.5
0.346 99.1 0.081 36.6 63.3
0.160 0.05
0.030-0.036 ~46 (Cs K X-ray)
Xenon-133m 2.26 d t.i. 100 0.233 8 92
0.029-0.035 ~59 (Xe K X-ray)
daughter 133Xe
Ytterbium-169 32.0 d c.e. 100 0.021 0.21 12.3
0.063 45.16 50.4
0.094 0.78 12.3
0.110 3.82 56.2
0.117 0.04
0.118 1.90 3, 2
0.131 11.42 13.5
0.177 17.31 17.7
0.198 26.16 25.7
0.240 0.12
0.261 1.74
0.308 11.04 0.7
This chapter addresses scientific and technical aspects related to assays of Pharmaceutical
Equivalence, Dissolution, Bioavailability and Bioequivalence applicable to medicines, with emphasis
to immediate-release solid pharmaceutical dosage forms (IRSPDF) of oral use and suspensions, in
the context of exchangeability between medicines. Biological medicines (vaccines, sera, blood
derivatives, etc.), biotechnological medicines, radiopharmaceuticals and phytotherapy medicines
require other considerations and, therefore, are not addressed.
The Brazilian Health Regulatory Agency (Anvisa) is responsible for the minutes of registration and
post-registration of medicines. The technical and scientific aspects presented in this chapter are in
line with the criteria adopted internationally and with the technical regulation in force in Brazil about
the related topics.
Generic medicines were implemented in Brazil in 1999, and in 2003 a specific technical regulation
was published for registration of similar/alternative medicines, as well as another regulation for
adjustment of registration of similar medicines that were already being sold in Brazil.
Similar/alternative medicines that were available in the market had been registered in compliance
with norms that allowed their sanitary registration through the concept of similarity to a previously
registered medicine, without the need to present, for the registration, results from in vitro or in vivo
tests related to proof of efficacy and safety. The new regulations for similar medicines published in
2003 were targeted at establishing isonomy of criteria for registration and renovation of registration
of non-innovative medicines (generic and similar), based on the precepts of quality assurance,
efficacy and safety.
Pharmaceutical Equivalence and Bioequivalence are criteria applicable to generic and similar
medicines. Bioequivalence may also be necessary for innovative medicines when changes or
adjustments are made to the formulation during the clinical development for extrapolation of efficacy
and safety data. There are also cases where Bioequivalence may replace phase II and III clinical trials
for registration of medicines with new concentrations, under new pharmaceutical dosage forms and
new associations.
For registration of a generic or similar medicine, the pharmaceutical industry must request to the
Brazilian Health medicine Agency (Anvisa) the indication of the reference medicine for conducting
the necessary assays for developing the formulation, the pharmaceutical preparation and the
manufacturing process, establishing the conditions for stability tests and specifications of the
medicine, to prove its Pharmaceutical Equivalence (in vitro) and Bioequivalence (in vivo) with the
reference medicine, a mandatory condition to prove the Therapeutic Equivalence between the
candidate to generic or similar and the reference medicine (usually, the innovative medicine which
bioavailability is known and the clinical efficacy and safety were proven for the sanitary registration).
The Therapeutic Equivalence between the generic medicine and the reference medicine, or between
the similar medicine and the reference medicine, allows the exchangeability in the moment the
pharmacist sells the medicine. When the medicines are considered Therapeutic Equivalents, it is
assumed that both will present the same efficacy and safety when being administered to the body, and
also have the same potential to cause adverse effects.
PHARMACEUTICAL EQUIVALENCE
The Pharmaceutical Equivalence corresponds to the evidence that two medicines are equivalent in
relation to results from tests in vitro. By definition, Pharmaceutical Equivalents are medicines that
have the same drug, that is, the same salt or ester from the same therapeutically active molecule, the
same pharmaceutical preparation and route of administration, and are identical in relation to potency
or concentration.
They must be formulated to meet the same updated specifications from the Brazilian Pharmacopoeia
and, in their absence, specifications from other codes authorized by the current legislation, or also
other applicable quality standards, related to identity, content, purity, potency, uniformity of content,
disintegration and dissolution time, as the case may be. However, they may differ in characteristics
such as aspect, excipients, mechanism of release, package, validity period and, within certain limits,
labeling.
Pharmaceutical Equivalence studies are targeted at assessing the quality of medicines through
comparative analysis between the test medicine and the reference medicine, and must necessarily be
conducted by laboratories authorized by Anvisa. Additionally, the studies must be conducted in
samples within their validity period, using Chemical Reference Substances from the Brazilian
Pharmacopoeia, made official through Resolution of the Collegiate Board of Anvisa or originated
from other pharmacopoeias. If such substances do not exist, the use of Characterized Chemical
Substances is admitted according to the current legislation.
The analytical methods employed for quality assessment of medicines have considerable importance
in the Pharmaceutical Equivalence study. The analytical methods described in the individual
monograph on the medicine present in the Brazilian Pharmacopoeia must be used, and if such
monograph does not exist in this compendium, the use of methods included in other pharmacopoeias
authorized by the current legislation is permitted. When there are no monographs for the product in
official pharmacopoeias, the study must be conducted using validated analytical methods,
complemented with assays described in general methods from the Brazilian Pharmacopoeia. The
compendial analytical methods or those transferred by the study sponsor must have their suitability
demonstrated through validation in accordance with the current regulations that establish criteria for
the validation of analytical methods.
The Pharmaceutical Equivalence tests must be conducted simultaneously in the medicine candidate
to generic or similar and in the reference medicine. It is worth highlighting that the medicine being
tested must not be developed and formulated to be superior to the reference medicine, but to present
the same characteristics related to drug release and to quality already established for the reference
medicine. The demonstration of Pharmaceutical Equivalence between the two medicines is an
indication that the candidate to generic, or similar, may present the same efficacy and safety as the
reference medicine.
Bioavailability (BA) is defined as the speed and extension of absorption of a drug, from a
pharmaceutical preparation that becomes available to make the pharmacological effect intended.
Depending on the goal and design employed in the study, the Absolute Bioavailability (ABA) of a
medicine or the Relative Bioavailability (RBA) between medicines is determined.
The ABA applies to innovative medicines that are developed as pharmaceutical dosage forms for
administration via extravascular routes. In general, it corresponds to a crossover assay, conducted in
healthy volunteers, comprised of two periods separated by a time interval named washout.
In the first period, the volunteers are distributed randomly in two groups (A and B). Volunteers from
group A receive the medicine being tested by extravascular route, while the same dose of the medicine
is administered, if possible, to volunteers from group B by intravascular route. The collections of
biological fluid are made according to procedures established in advance and, after the washout
interval, the second period starts, repeating the procedures with the same volunteers, but inverting the
groups. The drug concentrations in the samples are quantified employing a validated bioanalytical
method, which allows building the curves of concentrations versus time to make the calculations of
pharmacokinetic parameters in relation to the bioavailability.
When determined for a pharmaceutical preparation administered orally, for example, the ABA
corresponds to the systemic fraction calculated in relation to the dose administrated by intravascular
route, which bioavailability is, by definition, equal to 100%. If it is possible to administer the same
dose of medicine by oral and intravascular routes and the ABA calculated equals 80%, this means
that the oral dose application is not complete, because there was a loss of 20% that may be related to
characteristics of the drug, the individual or the formulation.
Cmax
Concentration (ng/Ml)
kel
Ct
Tmax
Time (h)
Figure 1 – Representation of curve of drug concentration on plasma with time after administering one dose of
medicine by extravascular route. Ct Drug concentration in the final collection point; Kel. Elimination speed
constant, ASC t-inf Area under the curve estimated from time t to infinite.
In the case of a generic medicine or a similar medicine, the development of the formulation must be
targeted at obtaining a pharmaceutical equivalent that, in vivo, does not present significant differences
in relation to the bioavailability of the reference medicine, which is assessed by employing a RBA
study adequately planned and an acceptance criterion applicable.
The Bioequivalence (BE) corresponds to a particular case of RBA and involves acceptance criterion
and statistical analysis that allow to conclude on the comparison of bioavailability between two
medicines with risk established in advance. Two medicines are considered bioequivalent and,
therefore, exchangeable when the Confidence Intervals (CI) of 90% calculated for the ratios of
geometric averages ASC0-t (T) / ASC0-t (R) and Cmax (T) / Cmax (R) are between 80% and 125%,
considering T the medicine being tested and R the reference medicine, a criterion adopted
internationally for acceptance of bioequivalence.
In general, the main factors that may change the bioavailability of medicines are related to the
individual (age, gender, body weight, associated pathophysiological factors) and to characteristics of
the medicine (drug, formulation and manufacturing process). In case of factors related to the
individual, their influence must be as minimized as possible, which occurs when the bioavailability
assay planning is properly executed, through defined inclusion and exclusion criteria, selection of a
representative group of volunteers in relation to the population for the study, and the employment of
an adequate experimental design.
Among the factors related to the medicine, there are: chemical nature of the drug; solubility; particle
size; polymorphism; type and amount of excipients; mixing and drying time; granulation and
compression technique; instability of drug. In this sense, it is considered mandatory to conduct studies
on pre-formulation and increase of scale to obtain a stable formulation, to be administered through a
pharmaceutical preparation and a route that are adequate to the therapeutic goal. Thus, the
professional involved in the pharmacotechnical development must have vast knowledge on the
physicochemical, pharmacokinetic and pharmacodynamic characteristics of the drug, also selecting
the most adequate pharmacotechnical adjuvants (excipients), as well as appropriate unit operations
for manufacturing.
Among the pharmaceutical dosage forms most commonly used in therapeutics, the solid forms of oral
use are those most subject to variability of bioavailability results due to characteristics of drug,
formulation, processes employed in manufacturing, and route of administration. In these cases, after
the administration, the drug dissolution process is essential for it to be in solution and be absorbed,
and may be a limiting factor for absorption. Likewise, suspensions of oral or intramuscular use may
generate challenges, since there is the drug dissolution process that suffers the influence of the factors
mentioned.
DISSOLUTION PROFILE
The dissolution profile can be defined as an in vitro assay that allows building the curve of percentage
of drug dissolved in relation to time, being proposed from conditions established in the dissolution
test described on the medicine monograph included in the Brazilian Pharmacopoeia or, in its absence,
in other compendia authorized by the current legislation. If the dissolution method does not exist in
the pharmacopoeia, the company requesting the registration must develop an analytical method
adequate to the product.
In case of medicines that will be submitted to the bioequivalence study, the assessment of comparative
dissolution profile in relation to the reference medicine allows knowing the behavior of formulations.
Similar dissolution profiles are an indicator that the test medicine may be bioequivalent to the
reference medicine.
PURPOSES
INTRODUCTION
This chapter considers as water for pharmaceutical use the various types of water used in the synthesis
of drugs, in the formulation and production of drugs, in testing laboratories, diagnostics and other
applications related to the health area, including as a main component in the cleaning of utensils,
equipment and systems.
Water has a peculiar chemical structure, with one dipole moment and great facility to form hydrogen
bonds. These properties make water an excellent medium to dissolve, absorb, adsorb or suspend
different compounds, and also to carry contaminants and undesirable substances, which may change
the purity and efficacy of a pharmaceutical product.
Due to its characteristics, the processes of purification, storage and distribution must ensure that the
pharmacopoeia specifications are met, maintained and controlled adequately.
The water quality requisites will depend on the purpose and use, and the selection of the purification
system is targeted at achieving the purity grade established. The user is responsible for selecting the
type of water adequate to their goals, as well as for the necessary controls and verifications, at
intervals that ensure the quality desired is maintained. They must ensure that the system presents
adequate performance and capacity to provide water with the quality level established to meet the
parameters specified in individual monographs.
This chapter does not exhaust the theme and does not intend to replace the legislation, guidelines or
existing official monographs on water for pharmaceutical purposes. The purpose is to present
subsidies that provide users with a better understanding on fundamental points related to the quality
of water in the moment of obtaining it and during its distribution and use.
Controlling water contamination is crucial, since water has a high capacity to aggregate compounds
and also be contaminated again after purification. Water contaminants are represented by two major
groups: chemical and microbiological.
Chemical contaminants
Organic and inorganic contaminants have different origins from the feed source; extraction of
materials with which water comes into contact; absorption of gases from the atmosphere; pollutant
residues; or residues from products used in equipment cleaning and sanitization, among many others.
This includes bacterial endotoxins, resulting from Gram-negative water microorganisms, critical
contaminants that must be removed adequately.
These contaminants can be assessed, especially, by the total organic carbon – TOC (5.2.30) and
conductivity (5.2.24) assays. The conductivity, measured in microsiemens/cm, is recommended to
assess water with a large amount of ions and its reciprocal, resistivity, is measured in megohm.cm
when there is low concentration of dissolved ions.
Most organic compounds can be removed by reverse osmosis. However, those with low molecular
mass demand additional techniques, such as ion exchange resin, electrodeionization, activated
charcoal, or oxidation by ultraviolet or ozone, to be removed.
The limits established for parameters of organic and inorganic chemical contaminants are targeted at
protecting the health and preventing critical chemical compounds from interfering with the water
system pre-treatment phase, considering that they may be difficult to remove on a later step.
Microbiological contaminants
They are represented mainly by bacteria and present a major challenge to water quality. They come
from the own microbiota of the water source and from some purification devices. They may also
appear due to inadequate cleaning and sanitization procedures, that allow the formation of biofilms
and, consequently, install a continued cycle of growth from organic compounds that, ultimately, are
nutrients for the microorganisms.
Bacteria may affect the water quality by deactivating reagents or changing substrates by enzyme
action, increasing the content in TOC, changing the base line (background noise) in spectral analysis,
and produce pyrogens, such as endotoxins.
The bacterial count is reported in colony-forming units per milliliter (CFU/mL) and, in general,
increases with water storage time. The most frequent contaminants are Gram-negative rods,
especially from the genera Alcaligenes, Pseudomonas, Escherichia, Flavobacterium, Klebsiella,
Enterobacter, Aeromonas and Acinectobacter.
The microbiological standard is specified, in parallel to chemical contaminants, and consists of the
absence of total and thermotolerant coliforms (pathogenic microorganisms of fecal origin), as well as
enteroviruses, cysts and oocysts from protozoans, such as Giardia sp and Cryptosporidium sp in a
100 mL sample.
To comply with these limits, treatment stations use disinfection processes with chemical substances
that have chlorine or other oxidants, employed for decades and considered relatively safe for humans.
However, these oxidants may react with the organic material of natural origin and generate secondary
products from disinfection, such as trihalomethanes, chloramines, or also leave residues from the own
disinfectants. Such undesirable products require special attention from legislators and users.
In addition to these two essential groups of contaminants, there are the particulates, comprised of
silica, residues from pipes or colloids and that, in addition to being a risk to the quality of purified
water, may cause clogging and severely harm the purification process, for reducing its performance,
or even cause irreversible damages to equipment. They can be detected by filtration combined with
gravimetry or microscopy. In general, it is not necessary to identify the type of particle, only remove
it.
This chapter addresses some concerns about the main purification systems usually employed in the
production of water for pharmaceutical use, their main applications, monitoring and maintenance. It
also encompasses the purity parameters established for the types of water that are not addressed in
the current legislation.
TYPES OF WATER
Basically, there are three types of water for pharmaceutical use: purified water (PW), water for
injection (WFI), and ultrapure water (UPW), which monographs are included in this Pharmacopoeia.
Official international compendia specify, in addition to them, other types of water, such as: contained
in vials, sterile or bacteriostatic, for irrigation or inhalation. However, all of them have purity
characteristics similar to the fundamental types already mentioned.
In addition to them, there is potable water, which is widely used and has direct application in
pharmaceutical facilities, especially in general cleaning procedures. Thus, the four types of water
below are considered, in relation to their main characteristics and suggestions of application. The
specific monographs, when available, detail the purity parameters established for each type.
Potable water
As a fundamental guideline, the starting point for any process of purification of water for
pharmaceutical purposes is potable water. It is obtained by treatment of water taken from springs,
through adequate processes to meet specifications from the Brazilian legislation related to physical,
chemical, microbiological and radioactive parameters, for a certain standard of potability and,
therefore, has no specific monograph in this compendium.
Potable water is usually employed in the initial steps of cleaning procedures and as a source for
obtaining water of the highest purity grade. It may also be used in the thermal climate control of some
apparatuses and in the synthesis of intermediate ingredients.
The strict control and the maintenance of compliance with water potability parameters are
fundamental, critical and of responsibility from the user of the purification system that will be fed.
The control must be periodical to ensure that the purification system used is adequate for the
conditions of the feed source and that there was no change in the quality of the water provided.
However, most applications require additional potable water treatments, whether through distillation,
deionization, ion exchange, reverse osmosis, isolated or coupled, or another adequate process to
produce purified water, free from interference of contaminants that may affect the quality of the
medicines produced.
Purified water is produced from potable water and must meet the specifications established on the
respective monograph. It does not have any other substance added. It is obtained by a combination of
purification systems in a logical sequence, such as: multiple distillation; ion exchange; reverse
osmosis; electrodeionization; ultrafiltration; or another process capable of meeting, with the desired
efficiency, the limits specified for different contaminants.
Depending on the application, it may be sterilized, without necessarily achieving the limit of bacterial
endotoxins established for Water for injection.
It needs monitoring on the count of total viable aerobic organisms, in production and storage, since it
has no added growth inhibitor. As a minimum, it is characterized by a conductivity of no more than
1.3 µS/cm at 25.0 °C (resistivity > 1.0 MW-cm) and TOC ≤ 0.50 mg/L and total bacterial count ≤
100 CFU/mL, unless specified otherwise. The entire system for obtaining, storing and distributing
must be duly validated and monitored for conductivity and microbial count parameters.
Even if a maximum microbial count of 100 CFU/mL is specified in the monograph, each facility must
establish its alert or action limit, if the specific characteristics of use are more restrictive.
Ultrapure water has low ion concentration, low microbial burden, and low TOC level. This type of
water is required in more demanding applications, especially in test laboratories, for dilution of the
reference substances, in quality control, and in the final cleaning of equipment and utensils used in
processes that come into direct contact with the sample that requires water with this level of purity.
It is ideal for analysis methods that require minimum interference and maximum precision and
accuracy. The use of ultrapure water in quantitative analysis of low analyte contents is essential for
obtaining precise analytical results. Other examples of application of ultrapure water are: analysis of
residues, such as traces of mineral elements, endotoxins, preparations of calibrators, controls,
chemical reference substance, atomic absorption spectrometry in general, ICP/IOS, ICP/MS, mass
spectrometry, enzyme procedures, gas chromatography, high-performance liquid chromatography
(determination of residues in ppm or ppb), methods in molecular biology and with cell culture, etc. It
must be used at the moment it is produced, or in the same day of collection.
The laboratory must use the same type of water required for final reading of analysis in the preparation
of samples, when obtaining the standard curve, controls, preparation of solutions, blanks, final
material washing, and in all glassware that will come into direct contact with the sample, whenever
appropriate.
Ultrapure water is characterized by a maximum conductivity of not more than 0.055 µS/cm at 25.0
°C (resistivity > 18.0 MW-cm), TOC ≤ 0.50 mg/L, endotoxins < 0.25 EU/mL (when high biological
quality is required) and total bacterial count ≤ 10 CFU/100 mL.
Water for injection is used as excipient in the preparation of parenteral pharmaceutical products of
small and large volume, in the manufacturing of active ingredients of parenteral use, sterile products,
other products that require control of endotoxins and are not submitted to a later step of removal. It
is also used in cleaning and preparation of processes, equipment and components that come into
contact with drugs and sterile medicines during their production.
The purification process of first choice is distillation, in an equipment with internal walls made of
appropriate metal, such as AISI 316L stainless steel, neutral glass or quartz. Alternatively, WFI can
be obtained by a process equivalent to distillation or higher for removal of chemical contaminants
and microorganisms, provided that validated and monitored for the parameters established. The feed
water must be, as a minimum, potable and, in general, will need to be pre-treated to feed the
equipment. The process is thus specified due to the robustness such equipment presents concerning
operation and performance.
Water for injection must comply with the physicochemical tests established for purified water, as well
as with tests on total bacterial count ≤ 10 CFU/100 mL and bacterial endotoxins, which value must
be lower than 0.25 EU/mL.
Some quality parameters and suggestions for applications are registered on Table 1, for each type of
water for pharmaceutical use.
Designs, installations and operations of systems for production of purified water (PW), ultrapure
water (UPW) and water for injection (WFI) have similar components, controls and procedures. The
difference is in the presence of the parameter bacterial endotoxins on water for injection and in their
methods of preparation, specifically in the final stage. These similarities of quality parameters allow
to establish a common base for the design of systems targeted at obtaining PW, UPW or WFI, being
differential critical points the degree of control from the system and the final stages of purification
necessary for removing bacteria, bacterial endotoxins and reducing conductivity.
The processes for obtaining employ sequential unit operations – the purification stages – that are
targeted at removing certain contaminants and protecting the subsequent purification stages. Notice
that the final unit operation for obtaining water for injection is limited to distillation or another
equivalent process or higher, in the removal of chemical contaminants, as well as microorganisms
and their components. The distillation technique is renowned for its long history of reliability and can
be validated for production of water for injection. However, other technologies or combination of
technologies may be equally effective and validated for this purpose. Ultrafiltration placed in a
sequence after other chemical contaminant purification technologies may be adequate for the
production of water for injection, if it demonstrates the same effectiveness and reliability of
distillation in the validation.
For producing water for injection, there are new and promising applications that can be validated
thanks to the development of new materials for technologies such as reverse osmosis and
ultrafiltration, that allow operating and sanitizing at a higher temperature, allowing a more effective
microbial reduction.
The project for installing a water purification system must take into account the quality of the supply
water and the desired water at the end, the necessary flow, the distance between production system
and points of use, the layout of tubes and connections, the material employed, technical assistance
and maintenance facilities, and the adequate instruments for monitoring.
The purification technologies are targeted at removing contaminants in different stages of the
purification sequence. The main technologies presented below are in a logical sequential order, but
the selection of which ones will be used and the order they are applied will depend on the quality of
the potable water of admission and the type of water one aims at obtaining.
Pre-filtration
Also known as depth filtration or initial filtration, it is targeted at removing particulate contaminants
in the size range from 5 to 10 μm, essentially to protect subsequent technologies, using sand filters or
combination of filters.
This technology employs the adsorption capacity of vegetable activated charcoal in contact with
organic compounds or contaminants, such as chloramines. Additionally, it removes oxidizing agents
by chemical reduction, especially free chlorine, which affects other membrane-based technologies,
such as reverse osmosis or ultrafiltration.
The removal of sanitizing agents favors bacterial growth and formation of biofilm, which implies the
need for sanitization of the activated charcoal, with direct vapor or hot water, for example, and for
control of particles and microbial count of its effluent.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.5-01
The use of chemical additives refers to the ones targeted at adjusting the pH or removing carbonates
and ammonia, for protection of other technologies, such as reverse osmosis.
As chemical additives, ozone, commonly used in the control of microorganisms, and metabisulfite,
applied as reducer agent for free chlorine, may be used as substitutes to vegetable activated charcoal.
Chemical additives are necessarily removed in some later stage of purification and cannot leave
residue in the final water.
In cases where the feed water is “hard”, it is necessary to use softeners. This technology employs
regenerable ion exchange resins, which capture calcium and magnesium ions and release sodium ions
in water. Softening is used in the protection of technologies sensitive to incrustation, such as reverse
osmosis.
It is necessary to control the microbial count, with frequent regeneration, recirculation or other forms
of reduction of microbial count, to avoid the formation of biofilm.
Deionization and continuous electrodeionization are effective technologies for removal of dissolved
inorganic salts. Deionization systems, also known as conventional deionization, produce purified
water for routine use, through specific ion exchange resins for cations or for anions. They are organic
polymers, generally sulfonated, in the form of small particles. Cationic resins capture ions releasing
the ion H+ in water, and anionic resins release OH-. They are regenerable with acids and bases,
respectively. This process alone does produce high purity water, due to leak of small fragments of
resin, facility of microbial growth, and low removal of organics.
Continuous electrodeionization systems combine cationic and anionic resins with semipermeable
membranes and the application of an electric field, promoting the continuous removal of ions, that is,
without the need to stop for regeneration. In both cases, it is necessary to have control over the
generation of particles resulting from successive regenerations, as well as microorganisms. This can
be done by controlling regenerations, in the case of deionization, using water recirculation and
applying UV radiation for control of microorganisms in the outlet, which effectiveness must be
proven.
Reverse osmosis
Reverse osmosis is a purification technology based on semipermeable membranes and with special
properties for removal of ions, microorganisms and bacterial endotoxins. It removes 90% to 99% of
most contaminants. However, different factors, such as pH, differential pressure along the membrane,
temperature, type of polymer of the membrane, and the construction of the reverse osmosis cartridge
may significantly affect this separation.
Reverse osmosis membranes must be duly control for the formation of incrustations coming from
calcium salts, magnesium salts and other salts, and of biofilm, a critical source of microbial
contamination and endotoxins. For this reason, it is mandatory to install a pre-treatment system before
reverse osmosis that removes particles and oxidizing agents and, in parallel, the system sanitization
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.5-01
must be conducted periodically. This practice helps increase the work life of membranes and reduces
the frequency of their regeneration.
There are double pass reverse osmosis systems, where water purified by the first step feeds the second
step, increasing and complementing the purification.
Ultrafiltration
Ultrafiltration is frequently used in systems of water for pharmaceutical use for removal of
endotoxins. The ultrafiltration is conducted using a special membrane with the property of retaining
molecules according to their molecular mass and stereochemistry. The range used for particle
separation is named Molecular Weight Cutoff, characterized by the size of molecular mass. Filters in
the range of 10.000 Da, which retain molecules with molecular mass of 10,000 Da or higher are used
in the removal of endotoxins.
This technology can be used in a final or intermediate step of the purification system, provided that
validated, and, like reverse osmosis, requires pre-treatment, adequate control of the operating
conditions, and adequate cleaning and sanitization procedures, to maintain the water quality as
established.
This type of filtration employs positive charges on the surface of membranes and is targeted at
reducing the levels of endotoxins that have negative electric nature. It presents marginal capacity for
removal of microorganisms, but its greater efficiency is due to the removal of endotoxins. It has an
important limitation: when the charges are completely neutralized, by saturation due to the capture of
endotoxins, the removal is paralyzed. For this reason, filters with electrostatic charge are extremely
difficult to validate, due to this unpredictability concerning the moment they effectively no longer
retain such contaminants.
This technology uses microporous membranes, with pore size specification of 0.2 or 0.22 μm. They
must be validated for retention, through a bacteriological test, which determines the value of the log
reduction of microorganisms on the membranes. The model used employs a suspension of
Brevundimonas diminuta at 107 CFU/cm2 of filtering area and tests the sterility of the filtrate. Even
if the membrane is specified as 0.2 or 0.22 μm of pore diameter, it will not necessarily be sterilizing
if it does not produce a sterile filtrate through this test, that is, a log reduction value equal to 7. If the
log reduction obtained is not around seven, the membrane can be used to reduce the microbial count,
but must not used to sterilized.
Microfiltration is applied to the filtration of gases or ventilation of storage tanks, to avoid the
contamination of water stored in them. In such cases, hydrophobic membranes are used, for the filter
to operate without condensed water buildup, from air humidity.
UV radiation is used in water purification systems in two wavelengths: 185 nm and 254 nm, which
promote two effects:
• 185 nm and 254 nm – Oxidation of organic compounds and consequent reduction of their
concentration, to achieve the limits from PW, UPW and WFI;
• 254 nm – Germicide action at different points of the purification sequence, to reduce microbial
count.
For the oxidation of organics, the water must be on the final stage of purification, and this removal
will be more effective the lower the contaminant load is. It is necessary to monitor the intensity of the
lamp and consider the depth/thickness of the bed and the water flow at the radiation site.
Distillation
In industrial facilities, there may be simple, multiple effect and vapor compression distiller, which
are generally used for large volume production systems. Feed water for such equipment requires
controls different from the ones used in reverse osmosis. In this case, the concentration of silicates is
critical, like in any vapor generation system. Another important aspect is the possibility of carrying
volatile compounds in the condensate. This is specially important when it comes to organic impurities,
such as trihalomethanes and gases dissolved in water, such as carbon dioxide and ammonia. Thus,
the control of inlet potable water is essential, as mentioned about feed water for purification systems.
Distribution
The distribution system design must take into account the constant recirculation of purified water and
water for injection and the maintenance of temperature of the water stored in the tank. If necessary,
it must have a heat exchanger to provide colder water to the points of use.
Tubes, valves, instruments and other devices must have sanitary construction and finishing, so that
they do not contribute for microbial contamination and are sanitized.
Microbiological retention filters must not be used on the outlet or in the return from distribution
systems, because they are deposits of retained microorganisms and, therefore, a critical source for the
formation of endotoxins. The points of use must be designed in order to avoid dead volumes and
allow water to completely recirculate in them when they are closed.
Sanitization
There are different methods for sanitization of production, storage and distribution systems. The
system construction material must be resistant to the agents employed and the temperature used in
the process is critical. It is common to use temperatures of 80 °C or 65 °C, with continuous water
circulation. However, to prevent the formation of biofilms, a combination of heat and chemical agents
is usually employed in sanitization. The sanitization procedure must be duly validated.
Storage
The storage conditions must be adequate to the water quality. Ultrapure water must not be stored for
a period larger than 24 hours. The fundamental guideline for storage of purified water, ultrapure water
or water for injection is to weight that, the higher the water purification grade, the faster it tends to
recontaminate.
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.5-01
Thus, water must be maintained in constant recirculation, through its distribution system, whenever
applicable. The first portions of water produced by a purification system that has been inactive for
more than four hours must be discarded proportionally to the dead volume of the container. Such
variables must be validated for the specific conditions of each system, and the parameters to be
considered in the validation must also be established.
The reservoir used for its maintenance must be appropriate to the purposes it is targeted at, being
comprised of inert, clean material and not be a source of contamination to the content. The
construction material must present appropriate characteristics and rugosity to prevent the adherence
of residues, formation of biofilm and corrosion by sanitizing agents. Electropolished 316L stainless
steel, with rugosity below 0.5 microRA, is the most frequent choice to meet these requirements. The
reservoir must be protected from improper sources of light and heat, and the geometry must allow its
total drainage from the bottom, without dead volumes.
In particular, but not exclusively, reservoirs of water for injection must be sleeved to maintain the
circulating water at temperature higher than 80 °C, which significantly restricts the bacterial growth.
Validation
The fundamental purpose of validation is to ensure the reliability of a water purification system,
involving acquisition, storage, distribution and quality at the point of use. Validation includes the
project qualification (PQ); facility qualification (FQ); operation qualification (OQ); and performance
qualification (PQ).
The validation plan for a water system involves the following phases:
a) knowing the feed source quality standard;
b) establishing the purified water quality standard;
c) defining the purification technologies and their sequence, from inlet water quality;
d) selecting the construction materials for the production, storage, distribution and monitoring
systems of the points of use;
e) developing protocols for qualification of design, installation, operation and performance;
f) establishing critical parameters, alert and action levels, and periodicity of sanitization and
monitoring;
g) establishing a maintenance plan for validation, which will include mechanisms for control of
changes to the water systems and will provide subsidies for a preventive maintenance program.
Water quality monitoring must encompass all critical and representative points of the system,
according to the planning established, in a consistent and continuous manner. Water quality
monitoring must be conducted through physicochemical and microbiological analysis.
Equipment and apparatuses used in verifications must be capable of providing the reading in the range
required for the purity established. The equipment used must be duly calibrated. The verifications
made must be registered in an adequate form, which includes, as a minimum, the parameter(s)
measured, measurement date, value obtained, acceptance range, and person responsible for the
reading. The personnel who executes this task must know the sampling plan and the methods used,
as well as the alert and action limits established. If the user outsources this control, they must ensure
that the outsourced party meets the requirements and procedures defined.
The data obtained are compared with typical specifications and with alert and action limits. They are
established by the user, based on validation data, history of the purification and distribution system,
and quality requirements for a certain application.
The use must define the alert and action limits, to avoid obtaining a product with quality specification
inferior to the one required for a given application. The alert limit indicates that a deviation in quality
may happen and not necessarily requires a corrective measure. It may be established based on a
statistical analysis of the history of trends, using two standard deviations, for example, or
approximately 70% of the action limit, or 50% of the count of number of viable units, whichever is
lowest. The action limit indicates that the quality deviation exceeded the tolerable parameters and
requires activity interruption for correction. Non-compliant results require extraordinary intervention
at the site, in addition to regular operations, to restore the system so that the quality standard expected
is maintained.
PHYSICOCHEMICAL MONITORING
The physicochemical monitoring follows, especially, the conductivity and total organic carbon, which
can also be monitored in line. These assays cover a large number of inorganic contaminants. If the
sample is not analyzed after the collection, it must be maintained and stored in conditions that
guarantee its integrity and preservation for an adequate period. Depending on the application required,
the critical parameters to be monitored may vary.
MICROBIOLOGICAL MONITORING
The importance of controlling water for pharmaceutical use is in ensuring its quality in order to
comply with the parameters determined in each monograph and avoid contamination carrying to the
products. Thus, it requires strict microbiological quality control, since, due to its intrinsic
characteristics and the processes involved in its production, it is highly susceptible to microbial
contamination.
The target of microbiological control are pathogenic bacteria, with the need for identifying or
selecting certain species of microorganisms that may be harmful to processes and products, such as,
for example, Pseudomonas aeruginosa, Burkholderia cepacia, Escherichia coli and Salmonella sp.
Tests intended for microbiological monitoring of water for pharmaceutical use are described on
Microbiological assays on water for pharmaceutical use (5.5.3.6).
SUBSTANCES
According to the WHO definition, pharmacopeial reference standards (PRef) are products of
recognized uniformity, intended for use in tests where one or more of their properties will be
compared with those of the substance under examination. They have a degree of purity suitable for
their intended use.
The PRef is established and distributed by pharmacopeial authorities, whose value attributed to one
or more of its properties is accepted without the need for comparison with another standard, intended
for use in specific tests described in pharmacopoeial monographs. They include chemical reference
substances, biological products, plant extracts and powders, radiopharmaceuticals, among others. The
most commonly used related expression is: Pharmacopoeial Chemical Reference Substance.
The Chemical Reference Substances from the Brazilian Pharmacopoeia (CRS–BP) are
pharmacopoeial reference standards, which production is under coordination by the Thematic
Technical Committee on Chemical Reference Substance (CTT CRS) from the Brazilian
Pharmacopoeia, in line with guidelines from the Brazilian Pharmacopoeia Commission.
The CRS-BF are established and monitored according to principles from the WHO, with
collaboration from public and private laboratories, through interlaboratory studies that use an
analytical protocol developed and validated in advance, originating a product with high quality, which
value attributed to one or more of its physical and/or chemical properties does not need comparison
with another CRS.
Analytical methods frequently use sophisticated equipment to facilitate the precision and agility of
the procedure used, based on relative measures, that need reference standards for obtaining results.
The CRS-BF are developed to help in the conduction of assays described in monographs from the
BF. Their purity grade may vary according to the assay it is targeted at. The stated value is specific
to the assay described on the BF.
The CRS-BF must be stored and handled adequately in order to obtain reliable results when used.
They must be stored in the original vials, closed and at temperature and humidity conditions according
to specifications included in the label and/or certificate of analysis.
The amounts provided in each vial of CRS-BF are adequate for a certain number of analysis, in order
to avoid issues with excessive exposure of material. However, the amounts and their value are
targeted at stimulating the direct use of CRS-BF, without the need to establish derivate standards.
When drying the material before use is indicated, this procedure will never be conducted in its original
package, but by transferring part of the material to another container. After use, the desiccated
material must not be returned to the original vial, avoiding possible contaminations.
The validity of a certain batch must be monitored by the user through the Brazilian Pharmacopoeia
website, which will inform the batch in force, the removal of batches in use and the availability of
new batches. This website also offers information for acquisition of pharmacopoeial reference
standards.
Coloring agent is any organic or inorganic compound, natural or synthetic, which, regardless of
having pharmacological activity or not, is added to medicines, foods, cosmetics or correlates with the
single purpose of coloring them or changing their original color.
The basic difference between pigments and dyes is in the particle size and solubility in the medium
it is inserted. Pigments, in general, have larger particle size and are insoluble in water, while dyes are
water-soluble molecules. It is possible to state that dyes are employed in solutions, and pigments, in
suspensions. Additionally, pigments have higher chemical and thermal stability than dyes.
The solubility of the dye can be determined by the presence of certain chemical groups in the structure
of the compound, which may cause differentiations between pigments and dyes.
The dyes used are mostly of synthetic origin and can be, in general, classified in one of the seven
chemical groups described below:
• Indigoid Group;
• Xanthine Group;
• Azo Group;
• Nitro Group;
• Triphenylmethane Group;
• Quinolone Group;
• Anthraquinone Group.
Dyes can also be divided into azoic dyes (which have -N=N- groups) and non-azoic dyes (belonging
to a wide range of chemical classes). Most dyes of more frequent use are of the non-azoic type, with
erythrosine, indigo / carmine and quinoline yellow being the three most widely known.
Concerning pigments, two types are used: iron oxide (black, red and yellow), and titanium dioxide,
which is white and also used in tablet coating, to prevent the photodegradation of components from
the formulation that are sensitive to light, or also to obtain opaque capsule shells.
Dyes can be classified, according to the Food and Drug Administration (FDA), into:
• dyes designated as Food, Drug and Cosmetics (FD&C) can be employed in foods, medicines and
cosmetic products;
• dyes designated as Drugs and Cosmetics (D&C) are authorized for use in medicines and cosmetics;
• D&C dyes of external use have their employment restricted to medicines and cosmetics applied
externally;
Coloring agents included on the table below (Table 1) or a mixture of these agents can be added to
medicines targeted at application via oral, rectal, vaginal or cutaneous route in cases and in amounts
compatible with good pharmaceutical manufacturing practices.
The coloring agents employed must meet the requirements described in the respective monographs.
This table also identifies dyes for use in correlates such as: contact lenses, general surgery sutures,
sutures for ophthalmic surgery, intraocular lenses (for haptic coloring), bone cement, and gelatinous
contact lenses (to identify left or right size).
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
Curcumin (1E,6E)-1,7-bis
Turmeric
Yellow curcumin 458-37-7 yellow; (4-hydroxy-3-methoxyphenyl) 75300 73615 E100 Used on foods.
oleoresin
turmeric hepta-1,6-diene-3,5- dione
Used in medicines administered orally (not
iron oxides obtained by
exceeding the daily dose of 5 mg of Fe) and
synthesis, including they
yellow iron yellow iron yellow iron topical use.
Yellow 51274-00-1 hydrated forms or combinations 77492 731.200 E172
oxide oxide oxide Not permitted in the eye area, in medical
of more than one of these
devices, and in injectable pharmaceutical
oxides
dosage forms.
7,8-dimethyl-10-[(2S,3S,4R)-
vitamin B2 2,3,4, 5- tetrahydroxypentyl]
Yellow riboflavin 83-88-5 riboflavin N/C 73.450 E101 Used on foods.
lactoflavin benzo[G]pteridine-
2,4-dione
Used on foods, cosmetics and medicines of
trisodium (4E)-5-oxo- internal and external use.
tartrazine
1-(4- sulfonatophenyl)- Not permitted in medical devices and in
yellow; FD&C
Yellow tartrazine 1934-21-0 4-[(4-sulfonatophenyl) 1910 741.705 E102 injectable pharmaceutical dosage forms.
yellow 5 yellow #5
hydrazinylidene] pyrazole-3- Products for human use by oral, nasal, rectal
INS 102
carboxylate or vaginal route, or for use in the eye area,
must specifically state the dye on the label.
aluminum;
tartrazine 4-[[3-carboxy-5-oxo- Used on foods, cosmetics and medicines of
yellow 1-(4- sulfophenyl)-4H- internal and external use.
FD&C
tartrazine, aluminum pyrazol-4-YL]diazenyl] Not permitted in medical devices and in
yellow #5
Yellow aluminum 12225-21-7 lake; yellow 5 benzenesulfonate; 19140:1 741.705 E102 injectable pharmaceutical dosage forms.
aluminum
lake aluminum 4-[[3-carboxy-5-oxo- Products for human use by oral, nasal, rectal
lake
lake 1-(4-sulfophenyl)- or vaginal route, or for use in the eye area,
INS 103 4H-pyrazol-4-YL]diazenyl] must specifically state the dye on the label.
benzenesulfonate
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
disodium 2-[[4-[ethyl-
[(3-
Used on foods (including nutritional
sulfonatophenyl)methyl]amino]
supplements), cosmetics and medicines in
blue n. 1 FD&C blue phenyl]- [4-[ethyl-[(3-
Blue Brilliant blue 3844-45-9 42090 741.101 E133 general, including the eye area.
INS 133 #1 sulfonatophenyl)methyl]azaniu
Use not permitted in medical devices and in
mylidene] cyclohexa-2,5-dien-
injectable pharmaceutical dosage forms.
1-ylidene]methyl]
benzenesulfonate
3-[[ethyl-[4-[[4-[ethyl-
[(3- Used on foods (including nutritional
brilliant blue n. 1 FD&C blue
sulfophenyl)methyl]amino]phe supplements), cosmetics and medicines in
blue, aluminum #1
Blue 68921-42-6 nyl]-(2-sulfophenyl) 42090:2 741.101 E133 general, including the eye area.
aluminum lake aluminum
methylidene] cyclohexa-2,5- Use not permitted in medical devices and in
lake INS 133 lake
dien-1-ylidene]azaniumyl] injectable pharmaceutical dosage forms.
methyl] benzenesulfonate
Used on foods, cosmetics and medicines
administered by oral route.
blue n. 2;
disodium (2E)-3-oxo-2- It may be used for coloring nylon and surgical
indigotin;
indigotin FD&C blue (3-oxo-5-sulfonato- 73015/ 74.1102 sutures in general surgery, bone cements,
Blue 860-22-0 indigo E132
blue #2 1H-indol-2-ylidene)- 75781 74.3102 subject to the following restrictions: the
carmine;
1H-indole-5-sulfonate amount of color additive must not exceed 1%
INS 132
in weight of the suture thread; not be absorbed
by surrounding tissues.
Used on foods, cosmetics and medicines
indigotin blue n. 2 FD&C blue aluminum (2E)-3-oxo-2-
administered by oral route.
blue, aluminum #2 (3-oxo-5-sulfo-1H-indol-
Blue 16521-38-3 73015 741.102 E132 It may be used for coloring bone cement,
aluminum lake aluminum 2-ylidene)-1H-indole-
provided it does not exceed 0.1% in weight of
lake INS 132 lake 5-sulfonic acid
bone cement.
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
ethanaminium, Used on foods and in radiographic study of
N-[4-[[4- structures from the lymphatic system
(diethylamino)phenyl](5- (lymphangiography study).
patent blue, patent V blue; hydroxy-2,4- It may cause skin sensitivity, rash, pruritus,
Blue 3536-49-0 acid blue 3 42051 E131
calcium salt acid blue 3; disulfophenyl)methylene]- nausea, decrease blood pressure, cause
2,5-cyclohexadien-1-ylidene]- tremors and respiratory issues.
N-ethyl-, inner salt, calcium salt Not permitted for children.
(2:1) Prohibited in the USA, Norway and Australia.
acid blue 1;
food blue 3;
ethanaminium, N-[4-[[4-
Permitted exclusively in products that do not
(diethylamino)phenyl] (2,4-
carmine blue; come into contact with mucous membranes in
patent blue, disulfophenyl) methylene]-2,5-
Blue 129-17-9 patent blue acid blue 1 42045 E131 regular or predictable conditions of use.
sodium salt cyclohexadien-1- ylidene]-N-
VS Not permitted for children.
ethyl-, inner salt, sodium salt
Prohibited in the USA, Norway and Australia.
(1:1)
methylthion
methylthioni methylene inium 3,7-bis(dimethylamino) Used in medicines, including bacteriological
Blue 61-73-4 52015
ne chloride blue chloride; phenothiazin-5-ium chloride dye, indicated in contrast.
basic blue 9
Used on medicines
calcium calcium calcium Use not permitted in the eye area, in medical
White 471-34-1 calcium carbonate 77220 731.070 N/C
carbonate carbonate carbonate devices, and in injectable pharmaceutical
dosage forms.
Used on medicines for external (including the
eye area) and internal use (excluding the eye
titanium titanium titanium
White 13463-67-7 dioxotitanium 77891 731.575 E171 area).
dioxide dioxide dioxide
Use not permitted in medical devices and in
injectable pharmaceutical dosage forms.
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
Used on medicines for external (including the
(2E,4E,6E,8E,10E,12E,14E,16
eye area) and internal use (excluding the eye
Z,18E)- 4,8,13,17-tetramethyli
Orange annatto 1393-63-1 orange n. 4 annatto 75120 731.030 E160B area).
cosa-2,4,6,8,10,12,14,16,18-
Use not permitted in medical devices and in
nonaenedioic acid
injectable pharmaceutical dosage forms.
1,3,3-trimethyl-2-
Used on medicines for external (including the
[(1E,3E,5E,7E,9E,11E,13E,15E
eye area) and internal use (excluding the eye
Beta beta- ,17E)- 3,7,12,16-tetramethyl-
Orange 7235-40-7 orange food 5 40800 731.095 E160E area).
carotene carotene 18-(2,6,6-trimethylcyclohexen-
Use not permitted in medical devices and in
1-yl)octadeca-1,3,5,7,9,11,13,
injectable pharmaceutical dosage forms.
15,17-nonaenyl] cyclohexene
(2E,4E,6E,8E,10E,12E,
Used on medicines for external (including the
14E,16E)- 2,6,11,15-
all-trans- eye area) and internal use (excluding the eye
beta-apo- tetramethyl-17-(2,6,6-
Orange 1107-26-2 INS 160E beta-apo-8'- 40820 N/C E160E area).
8'carotenal trimethylcyclohexen-1-yl)
carotenal Use not permitted in medical devices and in
heptadeca-2,4,6,8,10,12,14,
injectable pharmaceutical dosage forms.
16-octaenal
Used in cosmetics (in lipsticks no more than
5% per weight of final product) and medicines
sodium 4-[(2E)-2-
of external and topical use (not exceeding the
Persian D&C (2-oxonaphthalen-1-
Orange solar orange 633-96-5 15510 741.255 N/C daily dose of 5 mg), dentifrices and
orange orange # 5 ylidene)hydrazinyl]
mouthwashes.
benzenesulfonate
Not permitted in medical devices and in
injectable pharmaceutical dosage forms.
Used in medicines of topical use and oral
administration.
natural brown Not permitted for children.
Brown caramel 8028-89-5 caramel NA - - E150A
10 Use not permitted in the eye area, in medical
devices, and in injectable pharmaceutical
dosage forms.
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
Used in medicines of topical use and
iron oxides obtained by
administered orally (not exceeding the daily
synthesis, including they
black iron black iron black iron dose of 5 mg of Fe).
Black 12227-89-3 hydrated forms or combinations 77499 731.200 E172
oxide oxide oxide Use not permitted in the eye area, in medical
of more than one of these
devices, and in injectable pharmaceutical
oxides
dosage forms.
chlorophyll mixture of chlorophylls A and
Green chlorophyll 1406-65-1 chlorophyll 75810 N/C E 140(1) Used on medicines and cosmetics.
INS 140I B
magnesium; 3-[18-
(dioxidomethylidene)-
8-ethenyl-13-ethyl-3,7,
chlorophylli chlorophylli
Green 15611-43-5 INS 140II 12,17-tetramethyl-20-(2-oxido- 75810 N/C E140(II) Used on medicines and cosmetics.
n ns
2-oxoethyl)-2,3-
dihydroporphyrin-23-id-2-
yl]propanoate; hydron
Used on cosmetics and medicines (including
the eye area).
It may be used for coloring nylon 66 and 6
disodium 5-methyl-2-[[4-(4- from surgical sutures in general surgery,
Brilliant D&C green methyl-2- sulfonatoanilino)- subject to the following restrictions: the
Green 4403-90-1 Alizarin green 61570 741.205 N/C
green #5 9,10-dioxoanthracen-1- amount of color additive must not exceed
yl]amino] benzenesulfonate 0.6% in weight of the suture thread; not be
absorbed by surrounding tissues.
Use not permitted in injectable pharmaceutical
dosage forms.
ethyl-[4-[ [4-[ethyl-
[(3-sulfophenyl)
Used on foods and medicines of external use
methyl]amino]phenyl]-
FD&C (including the eye area).
Green fast green 2353-45-9 food green 3 (4-hydroxy-2- 42053 741.203 N/C
green # 3 Use not permitted in surgical sutures and in
sulfophenyl)methylidene]-1-
injectable pharmaceutical dosage forms.
cyclohexa-2,5-dienylidene]-(3-
sulfophenyl)methyl] azanium
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
Used on cosmetics and medicines of external
use (including the eye area).
Used in simple, synthetic and absorbable
surgical sutures.
Use not permitted in injectable pharmaceutical
dosage forms.
1,4-bis(4-
Soluble Anthraquinon D&C green 74.1206 Used in contact lenses; polyethylene
Green 128-80-3 methylanilino)anthracene-9,10- 61565 N/C
green e green #6 74.3206 terephthalate surgical sutures, including
dione
sutures for ophthalmic use; polyglycolic acid
surgical sutures with diameters lower than the
diameter USP 8-0, including sutures for
ophthalmic use; poly sutures (co-trimethylene
glycolic acid carbonate) in general sutures,
and intraocular lenses for support haptics.
Used on cosmetics and medicines of external
use. No more than 0.01% of the weight of the
Solvent Pyranine D&C green Trisodium 8-hydroxypyrene- final product.
Green 6358-69-6 59040 741.208 N/C
green green #8 1,3,6-trisulfonate Use not permitted in the eye area, in medical
devices, and injectable pharmaceutical dosage
forms.
It may cause asthma, eczema, hyperactivity,
allergic reactions and/or intolerance, rashes,
amaranth;
trisodium (4Z)-3-oxo-4- especially in asthmatic individuals or with
D&C red 2;
Bordeaux S [(4-sulfonatonaphthalen-1- intolerance to aspirin.
Red amaranth 915-67-3 acid red 27, 16185 N/C E123
INS 123 yl)hydrazinylidene] Not permitted for children.
trisodium
naphthalene-2,7-disulfonate Prohibited in Norway, United States, Russia
salt
and Austria. Very restricted use (foods) in
France and Italy.
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
amaranth
aluminum
It may cause asthma, eczema, hyperactivity,
lake;
allergic reactions and/or intolerance, rashes,
pigment red
especially in asthmatic individuals or with
193; aluminum; trisodium (4Z)-3-
amaranth, Bordeaux S intolerance to aspirin.
acid red 27 oxo-4-[(4- sulfonatonaphthalen-
Red aluminum 12227-62-2 aluminum 16185:1 N/C E123 Not permitted for children.
aluminum 1-yl)hydrazinylidene]
lake lake Prohibited in Norway, United States, Russia
lake; FD naphthalene-2,7-disulfonate
and Austria. Very restricted use (foods) in
and C red
France and Italy.
no. 2
Used on foods.
aluminum
lake
It may cause eczema, allergic reactions and/or
intolerance, rashes, especially in individuals
disodium (3Z)-4-oxo-3-[(4-
with intolerance to aspirin.
sulfonatonaphthalen-1-yl)
Red azorubine 3567-69-9 carmoisine carmoisine 14720 N/C E122 Not permitted for children.
hydrazinylidene]naphthalene-1-
Prohibited in Japan, Norway, Sweden and the
sulfonate
United States.
Used on foods.
It may cause eczema, allergic reactions and/or
intolerance, rashes, especially in individuals
azorubine, carmoisine, carmoisine disodium salt of
with intolerance to aspirin.
Red aluminum 84041-67-8 aluminum aluminum 2-(4’-sulfo-1’-naphthyl-azo)- 14720 N/C E122
Not permitted for children.
lake lake lake 1-naphthol-4-sulfonic acid
Prohibited in Japan, Norway, Sweden and the
United States.
Used on foods (including nutritional
erythrosine;
supplements), cosmetics and medicines of oral
red n. 3; FD&C red disodium 2-(2,4,5,7-tetraiodo-
administration.
Red erythrosine 16423-68-0 sodium #3 3-oxido-6-oxoxanthen-9-yl) 45430 741.303 E127
Use not permitted in the eye area, in medical
erythrosine. erythrosine benzoate
devices, and in injectable pharmaceutical
INS 127
dosage forms.
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
erythrosine,
dialuminum; 1’,3’,6’,8’-
aluminum Used on foods (including nutritional
tetraiodo-3-oxospyro[2-
lake, red n. 3 FD&C red supplements), cosmetics and medicines of oral
erythrosine, benzofuran-1,9'-xanthene]-
aluminum #3 administration.
Red aluminum 12227-78-0 2',7'-diolate; 1’,3’,6‘,8’- 45430 741.303 E127
lake; sodium aluminum Use not permitted in the eye area, in medical
lake tetraiodo-3- oxospyro[2-
erythrosine lake devices, and in injectable pharmaceutical
benzofuran-1,9’- xanthene]-
aluminum dosage forms.
2',7'-diolate
lake INS 127
iron oxides obtained by Used in medicines administered orally or of
synthesis, including they topical use (not exceeding the daily dose of 5
red iron red iron
Red 1309-37-1 red iron oxide hydrated forms or combinations 77491 731.200 E172 mg of Fe). Not permitted in the eye area, in
oxide oxide
of more than one of these medical devices, and in injectable
oxides pharmaceutical dosage forms.
Used on cosmetics and medicines of external
calcium (4Z)-3-oxo-4-[(1-
use.
red pigment D&C red # sulfonatonaphthalen-2-yl) 74.1334
Red 74336-37-1 red 34 15880 N/C Not permitted in the eye area, in medical
63 34 hydrazinylidene]naphthalene-2- 74.2334
devices, and in injectable pharmaceutical
carboxylate
dosage forms.
Used on foods, cosmetics and medicines of
disodium (3E)-3-[(2,4-
external use.
ponceau red FD&C red # dimethyl-5-sulfonatophenyl) 74.1304
Red 4548-53-2 red 4 14700 N/C Not permitted in the eye area, in medical
SX 4 hydrazinylidene]-4- 74.2304
devices, and in injectable pharmaceutical
oxonaphthalene-1-sulfonate
dosage forms.
disodium 2’,4’,5’,7’-
Used on cosmetics and medicines in general.
red phloxine D&C red tetrabromo-4,5,6,7- tetrachlor- 74.1327
Red red 27 13473-26-2 45410:2 N/C Not permitted in the eye area, in medical
O #27 O-3-oxospiro [2-benzofuran- 74.2327
devices and in pharmaceutical dosage forms.
1,9'-xanthene]-3',6'-diolate
D&C red
(2Z)-6-chloro-2-(6-chloro-4-
#30; Used on cosmetics and medicines in general.
methyl-3-oxo-1-benzothiophen- 74.1330
Red red 30 2379-74-0 red 30 indanthren 73360 N/C Not permitted in the eye area, in medical
2-ylidene)-4-methyl-1- 74.2330
brilliant devices and in pharmaceutical dosage forms.
benzothiophen-3-one
pink R
Red red 33 3567-66-6 Hispanic red D&C red disodium (3E)- 17200 74.1333 N/C Used in cosmetics (in lipsticks no more than
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
#33 5-amino-4-oxo-3- 74.2333 3% per weight of final product) and medicines
(phenylhydrazinylidene) of external and topical use (not exceeding the
naphthalene-2,7-disulfonate daily dose of 0.75 mg), dentifrices and
mouthwashes.
Not permitted in medical devices and in
injectable pharmaceutical dosage forms.
disodium (5E)-5-[(2-methoxy- Used on foods (including nutritional
FD&C red n. 74.340
FD&C red 5-methyl-4-sulfonatophenyl) supplements), cosmetics and medicines in
Red red 40 25956-17-6 40; Allura red 16035 74.1340 E129
#40 hydrazinylidene]-6- general. Not permitted in medical devices and
AC INS 129 74.2340
oxonaphthalene-2-sulfonate in injectable pharmaceutical dosage forms.
red 40 aluminum lake or calcium and
aluminum FD&C red aluminum lake, in substrate of Used on foods (including nutritional
red 40, 74.340
lake; Allura #40 disodium salt of 6-hydroxy-5- supplements), cosmetics and medicines in
Red aluminum 68583-95-9 16035:1 74.1340 E129
red AC aluminum (2-methoxy-5-methyl-4- general. Not permitted in medical devices and
lake 74.2340
aluminum lake sulfophenyl) azo-2- in injectable pharmaceutical dosage forms.
lake naphthalenesulfonic acid
Used on cosmetics and medicines in general.
In medicines, the combination of D&C RED #
red 7 calcium D&C red #7 calcium (4Z)-4-[(4-methyl-2-
6 and D&C RED # 7 must not be larger than 5
red 7, lake; lithol calcium sulfonatophenyl) 74.1307
Red 09/04/5281 15850:1 N/C mg/daily dose of medicine.
calcium lake rubine red lake; D&C hydrazinylidene]-3- 74.2307
Not permitted in the eye area, in medical
calcium lake red #7 oxonaphthalene-2-carboxylate
devices, and in injectable pharmaceutical
dosage forms.
(2S)-4-[2-[(2S)-2-carboxy-6-
hydroxy-5- [(2S,3R,4S,5S,6R)-
beet red; 3,4,5-trihydroxy-6-
Beet red, beet powder Used on foods.
Red 7659-95-2 betanin (hydroxymethyl)oxan-2-yl]oxy- N/C N/C E162
betanin beetroot red Not permitted for children.
INS 162 2,3-dihydroindol-1-yl] ethenyl]-
2,3-dihydropyridine-2,6-
dicarboxylic acid
cochineal 3,5,6,8-tetrahydroxy-1-methyl-
cochineal carmine; Carmine 9,10-dioxo-7-[3,4,5-trihydroxy-
Red 1260-17-9 75470 731.100 E120 Used on medicines in general.
red carmine; cochineal 6-(hydroxymethyl)-oxan-2-
natural red 4 yl]anthracene-2- carboxylic
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
INS 120 acid)
Used on cosmetics and medicines in general.
2’,4’,5’,7’-tetrabromo-3’,6’-
D&C red # 74.1321 Not permitted in the eye area, in medical
Red Eosin red 62342-51-2 red 21 dihydroxyspiro [2-benzofuran- 45380:2 N/C
21 74.2321 devices and in injectable pharmaceutical
3,9’-xanthene]-1-one
dosage forms.
Used on cosmetics and medicines in general.
disodium 2-(2,4,5,7-
pure eosin D&C red # 74.1322 Not permitted in the eye area, in medical
Red 95917-83-2 red 22 tetrabromo-3-oxido-6- 45380 N/C
red 22 74.2322 devices, and in injectable pharmaceutical
oxoxanthen-9-yl)benzoate
dosage forms.
Used in cosmetics and medicines of internal
and external use, except mouthwashes and
dentifrices. Provided that the amounts do not
exceed 1.7 mg/daily dose of the drug for
(1Z)-1-[(2-chloro-4- continuous use in less than 1 year.
Permanent D&C red # 74.1336
Red 70632-40-5 red 36 nitrophenyl)hydrazinylidene] 12085 N/C For medicines of continuous use for more than
red 36 74.2336
naphthalen-2-one 1 year, the amounts must not exceed 1.0
mg/daily dose of the medicine prescribed.
Not permitted in the eye area, in medical
devices, and in injectable pharmaceutical
dosage forms.
Used on medicines and foods.
It may cause eczema, allergic reactions and/or
trisodium (8Z)-7-oxo-8-[(4-
ponceau 4R; intolerance, rashes, especially in individuals
ponceau red sulfonatonaphthalen-1-yl)
Red 2611-82-7 red 2 ponceau 4R 16255 N/C E124 with intolerance to aspirin.
4R hydrazinylidene]naphthalene-
INS 124 Not permitted for children.
1,3-disulfonate
Prohibited in Norway and in the United
States.
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
Used on medicines and foods.
ponceau 4R aluminum lake or calcium and It may cause eczema, allergic reactions and/or
ponceau red
aluminum ponceau 4R aluminum lake, in substrate of intolerance, rashes, especially in individuals
4R,
Red 15876-47-8 lake; red 2 aluminum trisodium salt of 1-(4’-sulfo-1’- 16255 N/C E124 with intolerance to aspirin.
aluminum
aluminum lake naphthyl-azo)-2-naphthol-6,8- Not permitted for children.
lake
lake disulfonic acid Prohibited in Norway and in the United
States.
Used on cosmetics and medicines in general.
In medicines, the combination of D&C RED #
disodium (4E)-4-[(4-methyl-2-
6 and D&C RED # 7 must not be larger than 5
D&C red # sulfonatophenyl) 74.1306
Red Ruby red 5858-81-1 red 6 15850 N/C mg / daily dose of medicine.
6 hydrazinylidene]-3- 74.2306
Not permitted in the eye area, in surgical
oxonaphthalene-2-carboxylate
sutures and in injectable pharmaceutical
dosage forms.
74.1317 Used on cosmetics, medicines of external use
(1Z)-1-[(4-
D&C red # 74.2317 and contact lenses.
Red Scarlet red 85-86-9 red 17 phenyldiazenylphenyl)hydrazin 26100 N/C
17 74.3317 Not permitted for injectable pharmaceutical
ylidene] naphthalen-2-one
74.3230 dosage forms. Used in contact lenses.
Reference
Name in Color Reference
Color Dye CAS Synonym Description (IUPAC) European Uses, restrictions and requirements
English Index 21 CFR
Union
Used on cosmetics, medicines of external use.
Used in absorbable synthetic sutures for use in
general and ophthalmic surgery; Haptic media
from polymethyl metacrylate intraocular
lenses.
Not permitted in the eye area and in injectable
pharmaceutical dosage forms.
Used for synthetic surgical sutures of
copolymers with 90% glycolide and 10% L-
lactide in general and ophthalmic surgeries;
1-hydroxy-4-(4- 74.1602 synthetic polydioxanone surgical suture in
Alizarin D&C violet
Violet 81-48-1 violet 2 methylanilino)anthracene-9,10- 60725 74.2602 N/C general and ophthalmic surgeries; synthetic
violet #2
dione 74.3602 absorbable sutures of polyglecaprone 25 (Ɛ-
caprolactone/glycolide polymers) in general
surgeries; poly(Ɛ-caprolactone) absorbable
surgical sutures in general surgeries;
tripolymer absorbable sutures in glycolide
carbonate / dioxanone / trimethyl-ethylene in
general surgeries; surgical glycolide
homopolymer sutures in general surgeries;
intraocular lenses for support haptics; and
absorbable meniscus implants made of
poly(L-lactic) acid.
INTRODUCTION
The intended goal with this chapter is to present basic and necessary information for interpretation of
monographs on the main gases and mixtures used in Health Services, gases that comprise the mixtures
used in clinical tests, and gases used in the preservation of biological material.
This chapter encompasses gases classified by ANVISA as medicines and other gases used in Health
Services and in clinical laboratories.
Gases used in Health Services may be stored compressed under pressure; liquefied under high
pressure (saturated vapor pressure); liquefied at low pressure (cryogenic gases); or produced in the
site of consumption.
Medicinal gases are comprised of active substances or a mixture of active substances and gas
excipients.
The mixtures may consist of two or more substances or an active substance diluted in an excipient
gas. The percentage formula (v/v) is obtained from standard temperature and pressure (STP)
conditions. The density or compressibility factor for each gas under standard conditions (21 °C, 1
atm) are obtained from scientific data.
The monographs described the methods for analysis and the reference standards for quality assurance
of the product manufactured, and include details on physical state, molecular mass, CAS (Chemical
Abstracts Service) registration number, DCB (Brazilian Common Denomination) of minimum purity,
impurities and physical and organoleptic characteristics for each gas, storage and labeling.
Note – Medical compressed air or oxygen 93% v/v coming from compression systems or oxygen
concentrator systems, when produced in situ in Health Service centers, must follow the analysis
methods specified in their respective monographs.
USES
Medicinal gases described in this chapter represent the main gases available in the market.
In medical practice, the use of oxygen is aimed at keeping the patient respiration in condition of
saturation in arterial blood equal or superior to 90% v/v. In situations when oxygen is administered
diluted in another gas, its minimum concentration in the mixture must be 21% v/v. Medical oxygen
is usually especially in intensive care and in anesthetic procedures, as ventilatory support for patients
with respiratory failure of different clinical origins. In acute respiratory emergency situations, it
allows the cardiopulmonary reanimation of patients. In residential use, it is employed in oxygen
therapy, in case of pulmonary diseases. Oxygen is also used in hyperbaric therapy and as vehicle in
the administration of medicines by nebulization or inhalation.
Nitrous oxide is used in medicine and in odontology as an analgesic gas and, when associated to other
anesthetic agents in anesthesia procedures, as an anesthetic of regular potency. It must not be
administered at high concentrations (above 79% v/v) to patients, due to the risk of hypoxia. Nitrous
oxide, in mixtures with different concentrations, is always diluted with medical oxygen. The main
applications of medical nitrous oxide are in inhalation anesthesia procedures, always along with other
volatile anesthetics, in odontology procedures as a mild analgesic, and as an assistant in the control
of stress level in patients.
Carbon dioxide is used in the medical area especially in endoscopic surgeries, where it works as an
insufflator, such as in exploratory laparoscopy, for example. In situations where the gas is mixed with
oxygen and nitrogen, an atmosphere close to physiological is produced, applied in the creation of
anaerobic and aerobic atmospheres, for microorganism cultures. Mixtures of carbon dioxide with
nitrogen, or with nitrogen and oxygen, or pure carbon dioxide gas are used for calibration of blood
analysis and pulmonary diffusion devices.
Medical air (synthetic and compressed) is used as a source of fresh air in inhalation anesthetic
procedures and as ventilatory support to patients with respiratory failure of different origins and
clinical situations, associated or not to oxygen. It may be used for nebulization of patients, as a vehicle
for medicines in bronchial asthmatic episodes. In hyperbaric therapy, it is used as large chamber
filling gas, to create environments where patients are submitted to above-atmospheric pressures. It is
also used as gas for moving different types of pneumatic devices in Health Services.
Medical nitrogen has application in the medical practice in gaseous state and in cryogenic liquid state.
In gaseous state, it is used as impulsion agent for pneumatic devices in orthopedic, neurological and
other surgeries. As a cryogenic liquid, it is used in processes for freezing blood derivatives, cells and
embryos, bone marrow and in the preservation of organs. It can also be used in surgical techniques
named cryosurgeries, for example, in surgical treatment of infectious dermatoses.
With this mixture, the main goal is to reduce the stress level of the patient and, consequently, increase
the tolerance to pain. The mixture of compressed gas v/v 50% N2O + 50% O2 is used in analgesia
procedures, such as: orthopedic trauma; burns; esthetic and pediatric treatments. This mixture must
not be used in equipment and mixers for analgesia procedures, such as pure medical nitrous oxide or
pure medical oxygen.
MANUFACTURING METHODS
The fractional distillation process is started with the capture of atmospheric air in large volumes,
passing through two filters in air gas plants, named ASU – Air Separation Unit. The first filter, named
pre-filter, retains larger particles, while the second filter, of the pocket type, retains smaller particles.
After being filtered, the atmospheric air is suctioned by the main compressor. This air, after
compression, is sent to the purification system, where contaminants, such as CO2, H2O, THC (Total
Hydrocarbon Content), are eliminated. After purification, the compressed air goes through the heat
exchanger, which is comprised of two stages, where it is cooled to low temperatures and sent to the
high-pressure distillation column. In the distillation column, the air is cooled at low temperatures,
allowing the separation of nitrogen in form of gas that goes up through separation trays and, when
reaching the top of the column, one part is recycled and the other enters the condenser. In it, on its
turn, one part returns to the reflux column, the other part is sent to the fixed liquid nitrogen cryogenic
tank.
For obtaining oxygen, a remaining part of the nitrogen distillation is used. Oxygen is transferred from
the high pressure column to the low pressure column, causing a new liquefaction. The liquid oxygen
obtained in the lower extremity of the low-pressure column, is sent to the fixed liquid oxygen
cryogenic tank. Basically, there are no residues in the separation process, even if one of the gases is
released to the atmosphere and will automatically reintegrate the air composition. Note: If the
atmospheric air distillation process continues, the next product to be obtained is argon.
Through liquefaction of atmospheric air. After being filtered, the atmospheric air is suctioned by
the main air compressor. The compressed air is sent to the purification system, where contaminants,
such as CO2, H2O, THC (Total Hydrocarbon Content), for example, are eliminated. After purification,
compressed air goes through the main heat exchanger, where it is cooled down to low temperatures.
Atmospheric air in cryogenic form is sent to suction by compressor. This air obtained after the
compressor outlet is used for packaging in medical compressed air cylinders.
Through compressors. Atmospheric air can be compressed through pumps and compressors. The
compressed atmospheric air is obtained from compressors where the atmospheric air is suctioned and
compressed. The suction points must be out of contaminated places, such as combustion sources,
vehicle exhaust pipes, hospital garbage, or environments with outlet discharge of air conditioning
ducts and other discharge points. It is necessary to invest in compressors, filters, dryers and other
equipment that will provide adequate quality to use.
The process of manufacturing synthetic air for medicinal use is comprised of a binary mixture of
medical-grade oxygen and nitrogen. Oxygen is introduced in the cylinders and, then, nitrogen is
added. The introduction of nitrogen and then oxygen does not change or modify the final composition,
and its final concentration must be in compliance with the monograph on this compendium.
The manufacturing of medical nitrous oxide, also known as dinitrogen oxide, dinitrogen monoxide
or as laughing gas, occurs from the thermal decomposition of ammonium nitrate. Ammonium nitrate
is transported in two ways: in solid scales packaged in
natural fiber bags, or transported already in liquid form at temperature of 80 °C, in specific trucks.
Solid scales or the product in liquid form are transferred to reactors where the thermal decomposition
is held, occurring around 250 °C and, consequently, nitrous oxide and water are separated from the
other components, according to Equation 1.
Nitrous oxide is purified with potassium permanganate, sulfuric acid and sodium hydroxide. Purified
nitrous oxide is stored in fixed tanks from where they are transferred to tanker trucks, or then used
for packaging in cylinders, both targeted at final application.
The process for obtaining medical carbon dioxide, also known as carbon anhydride or carbonic gas,
can be executed from fermentation in sugar-alcohol industries, of from the combustion of materials,
or even as a byproduct of different chemical processes. According to the process for obtaining medical
carbon dioxide, there are different types of impurities, for example high content of hydrocarbons in a
combustion process and high content of nitrogen oxides in a fermentation process. The purification
of carbon dioxide for medicinal use is carried out during the acquisition process.
It is a compressed, homogenized gas mixture, packaged under high pressure. The process for
manufacturing the binary mixture for medicinal use is carried out by adding medical oxygen to
medical nitrous oxide. Medical nitrous oxide is initially introduced into the cylinder, followed by the
addition of medical oxygen. Introducing medical oxygen and then medical nitrous oxide does not
change or modify the final composition, but the final pressure of the mixture will be reduced due to
the critical pressure of nitrous oxide.
Oxygen 93% v/v for hospital use can be obtained by an oxygen concentrator system (OCS). In this
system, the oxygen concentrator is installed in the Health Service facilities and allows oxygen
concentration by submitting atmospheric air to a molecular sieve under low pressure. The process
retains nitrogen from air, which will be discarded, and allows oxygen, at the nominal concentration
of 93% v/v, to cross the adsorbent bed (molecular sieve) as a product. For use in Health Services, it
is mandatory to monitor the concentration of oxygen (through oxygen analyzers) during the
procedures.
For medicinal gases, there are several recommendations for appropriate handling, in order to ensure
safety in product use. There are specific recommendations that vary according to the type of
packaging and type of medicinal gas.
Cylinders for medicinal gases, for being a narrow and heavy cylindrical container, must always be
used in vertical position, duly fastened or over supports on their base. An exception is permitted to
cylinders targeted for transportation, which have lower dimensions and weights.
Medicinal gases packaged in cylinders are usually maintained under high pressure, requiring
additional care when opening the valve or connecting accessories. Medicinal gas may also be in liquid
form, usually in vacuum insulated cryogenic tanks. In this case, such gases may be at a cryogenic
temperature below -185 °C. Gases packaged in this liquid form may burn skin and other body organs
when in direct contact.
Depending on the type of gas, they may be highly combustible, asphyxiating or toxic. It is
recommended that the environment for using medicinal gases has good natural ventilation or a good
ambient air renovation system.
All safety recommendations, concerning the adequate handling of medicinal gases, must be verified
in the Chemical Material Safety Data Sheet (MSDS), in safety labels and in the hazard symbols made
available by the manufacturers in compliance with requisites from Associação Brasileira de Normas
Técnicas – ABNT NBR 14725 – Chemical Products – information about health, safety and
environment.
Monographs on medicinal gases from the Brazilian Pharmacopoeia require the standards used for
analytical determinations to be certified reference materials (CRM), with stated metrological
traceability. These CRM are produced by metrology institutes from several countries or
organizations, Brazilian or from other countries, acknowledged as certified reference material
producers. In the absence of such CRM, other reference materials (RM) produced according to norms
and guides internationally known, such as ISO 17034 – General requirements for the competence of
reference material producers, can be used.
STORAGE FORMS
Medicinal gases are, for the most part, stored in cylinders under pressure or in cryogenic tanks.
Packaging or filling
Operation that allows storing medicinal gases in cylinders and medical cryogenic liquids in mobile
cryogenic tanks.
They are usually made of metallic material, such as, for example, carbon steel or aluminum, without
seams or splices, and equipped with valves on top. Such valves may have connections with
differentiated threads for each type gas, to prevent the undue application of gas. The threads in these
connections have different diameters and steps, are internal or external, to the left or to the right to
minimize the possibility of connecting gases incompatible with the application.
Cylinders for gases have different sizes and support different levels of pressure, which determine the
capacity of storing gas in the compressed form. Usually, pure gas is stored in cylinders in a range
between 125 and 200 bar; however, this may vary in narrower or wider ranges for some specific
applications. In cylinders for gases, there may be medicinal gases in compressed form, under high
pressure, or in liquefied form, where the product is packaged as liquid and consumed in gaseous form.
The construction of cylinders follows the international norms DOT 3AA, DOT 3A and the Brazilian
norms ABNT EB 1199, ABNT EB 926 and others, offering safety to people who handle them
according to the correct safety procedures.
Knowledge about the information stamped on the cylinder dome is also important, as registered on
Figure 1.
(1) Valve; (1a) Valve handwheel; (1b) CGA connection; (1c) Safety device; (2) Cylinder cap; (3) Neck; (4) Cylinder
manufacturing specification; (5) Serial number; (6) Manufacturer’s DOT registration number; (7) Hydraulic capacity; (8)
Cylinder tare; (9) Manufacturer’s symbol; (10) Date of latest hydrostatic pressure test; (11) Certifier entity code; (12)
Manufacturing process; (13) Maximum service pressure
The valve is the least robust part of the set. For this reason, when the cylinder is not in use, it is
recommended to keep it with the cap or another protection device for protecting the valve in case the
cylinder falls or there are other unexpected events. On Figure 2 there is an example of a cylinder
valve used for medicinal gases.
SPRING
PACKING
NUT
HANDWHEEL
PACKING
UPPER
LOWER STEM
STEM
SEAT OUTLET
RUPTURE
DISC
INLET
Cryogenic tanks
Cryogenic tanks store medicinal gases in liquid form at extremely low temperatures. These tanks are
comprised of two chambers, one inside the other, usually in carbon steel or stainless steel. These
chambers are insulated from each other by vacuum and specific coatings, to preserve the product
under cryogenic temperature. The goal of storing medicinal gas in liquid form is to increase its
autonomy, since the use for human treatments is always under gaseous form.
In some situations, medicinal gas is used in liquid for, such as, for example, for dripping nitrogen for
dermatological treatments or for storing liquid nitrogen for maintaining long-preservation biological
samples.
Cryogenic tanks can be of the fixed or stationary type. Fixed cryogenic tanks are installed in health
service centers and replenished with medicinal gases by tanker trucks. The replenishment of mobile
cryogenic tanks, with medicinal gases in liquid form, is not made in the Health Service center, because
they are replaced after consumption.
Safety device
Medicinal gases stored in the forms described earlier must be in equipment with safety devices that
allow relieving the gas pressure, if there is an increase above expected, thus avoiding serious
accidents. The relief or rupture pressure of these devices is calculated due to characteristics of the gas
and cylinder in question. Basically, there are four types of safety devices:
Fusible plug. Contains an alloy with low melting point that, in case of cylinder heating, allows the
passage of gas.
Rupture disc. It is a metallic disc calculated to break at a certain pressure and allow total depletion
of the cylinder or tank.
Spring cage. Allows pressure relief and closes automatically when the cylinder or tank pressure
decreases.
FORMS OF TRANSPORTATION
Medicinal gases, packaged in cylinders or mobile cryogenic tanks, are transported in trucks that
ensure good ventilation, to prevent gas confinements due to safety issues, in vertical position and
properly fastened, since the gas containers, in case of fall, may cause severe accidents.
Liquefied medicinal gases are transported in tanker trucks, which are comprised of two chambers,
one inside the other, insulated by vacuum and other coatings that ensure the maintenance of
temperature at cryogenic levels. With medicinal gases transported in this manner, the fixed cryogenic
tanks installed in heath service centers are supplied.
The transportation of medicinal gases must comply with rules on transportation of hazardous
chemical products, according to resolutions from ANTT – National Road Transportation Agency,
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.8-00
since medicinal gases are also classified as hazardous chemical products and the delivery vehicles
must be appropriate and have the due safety identifications. Therefore, medicinal gases can only be
transported in duly suitable vehicles.
Some precautions that must be taken in the transportation of gas cylinders are listed below:
• when handling cylinders, hands and gloves must be maintained free from oil or grease;
• protect cylinders against shock. Do not let them fall and suffer impacts;
• always transport cylinders with the valve protection device;
• never use them as rolls or supports, even empty;
• do not lift or transport cylinders with steel cables adapted to the valve and/or cap;
• check, beforehand, if all valves are completely closed and if there are no leaks;
• disconnect from the cylinders all devices (regulators, hoses) before their transportation;
• all cylinders must be adequately fastened to the vehicles, always in vertical position.
It is also worth highlighting that the technical and scientific aspects presented in this chapter are in
line with the ones adopted internationally, as well as with the technical regulation in force in Brazil
concerning the themes addressed. In this context, it is important to stress that the actions for
registration and post-registration of medicines are the responsibility of the relevant sanitary authority.
BIOWAIVER
The BCS was proposed by Amidon et al in 1995 and consists of four classes according to
characteristics of solubility and permeability of the API (Box 1).
An API is considered highly soluble when its higher dose administered orally as an immediate-release
pharmaceutical dosage form (maximum dose per administration described in the package insert) is
completely dissolved in up to 250 mL of each of the buffer solutions used within the physiological
pH range (1.2 to 6.8), at (37 ± 1) °C. Active pharmaceutical ingredients of high permeability are those
which extension of absorption in humans is equal or superior to 85%.
EQUILIBRIUM SOLUBILITY
The equilibrium solubility of an API is a type of dynamic balance that occurs when the API in solid
state is in equilibrium with its solution. It may be obtained by determining the concentration of API
in a saturated solution, after a certain time and by stirring.
In the context of biowaiver, according to the BCS, the method of orbital agitation in vial (shake flask
method) is established for determining the API solubility.
In the method of orbital agitation in vial, better known as “shake flask”, the equilibrium solubility is
assessed through addition of excess of API to have its solubility determined in buffered aqueous
solutions with pH between 1.2 and 6.8. The API must be added to the aqueous solution and submitted
to agitation at controlled speed and temperatures. After achieving the equilibrium state of the
saturated solution, the equilibrium solubility can be determined. To confirm the equilibrium was
achieved between phases, the solubility must be constant in determinations made at consecutive
times. During the experiments, do not take aliquots of buffer solution that, when added, exceed 10%
of the total volume of the solution, because there may be dilution after the volume taken is
replenished. This procedure is necessary for maintaining the system hydrodynamics and the amount
of API above the saturation point.
For solubility studies, some rules must be followed: high purity of solvents; temperature maintained
at 37 °C throughout the experiment; the saturation must be achieved; and the method for
quantification of analyte in the saturated solution must be validated. Immediately after collecting the
aliquot of medium containing the analyte, the filtration is necessary, making sure that the API is not
adsorbed by the filtration system components.
For active pharmaceutical ingredients known to have high solubility (classes I and III from BCS), it
may be necessary to have a large amount of API to observe the formation of undissolved solid. In
these cases, to avoid using a large amount of API, it is acceptable to demonstrate that the maximum
dose of API per administration described in the package insert dissolves in up to 250 mL of the three
buffer solutions in the physiological pH range established.
Experimental part
Equipment: shaker with orbital movement, by bearings and eccentric shaft, with temperature control
adjusted to 37.0 °C and variation of no more than 1.0 °C.
Buffer solutions: for determining the equilibrium solubility, it is necessary to use: 0.1 M HCl solution
or simulated enzyme-free gastric fluid pH 1.2; 0.05 M acetate buffer solution pH 4.5 and phosphate
buffer solution pH 6.8 or simulated enzyme-free intestinal fluid pH 6.8 described on Reagents (14).
If the buffer solutions described are not adequate due to
physical or chemical nature, other buffer solutions may be used maintaining the pH values specified,
provided that technically justified.
PROCEDURE
Definition of amount of API and time for the experiment (preliminary assay)
From the API solubility data available on literature, weigh an excess of no less than 10% in mass and
transfer to an Erlenmeyer flask containing the adequate volume of buffer solutions pH 1.2; 4.5 and
6.8. Check for the presence of undissolved solid.
In case of absence of solubility data in literature, weigh a sufficient amount to check for the presence
of undissolved solid. Homogenize and measure the pH value and, if there is a change in relation to
the pH value of the buffer solution without the API, use a solution which buffer capacity maintains
the pH value specified for the medium. Cover the Erlenmeyer flask and adapt it to the orbital shaker.
Adjust the temperature to (37.0 ± 1.0) °C and the agitation speed to between 50 and 150 rpm. The
agitation speed must be established according to the volume of medium, in order to favor the balance
between phases, but avoiding the formation of vortex. When taking aliquots and replenishing the
solution, prevent the sum of volumes replenished from exceeding 10% from the total medium. After
this procedure, filter the aliquot and quantify the API.
Determine the amount of API dissolved with time and plot a chart, which will present an ascending
line followed by a plateau, which will indicate the equilibrium between the API dissolved and the
saturated solution. The determination of solubility must be made in time and with the amount of API
used to reach the plateau defined in this assay. Measure the pH value of buffer solutions after defining
the time to achieve equilibrium.
Weigh, accurately, at minimum in triplicate, for each pH condition to be assessed, an amount of API
no less than 10% above the mass determined during the preliminary assay and transfer to an
Erlenmeyer flask with an adequate volume of buffer solutions at pH 1.2; 4.5 and 6.8. Homogenize
and measure the pH value. Take an aliquot and quantify the API. Adapt the Erlenmeyer flasks to the
orbital shaker, adjust the temperature to (37.0 ± 1.0) °C and the agitation speed. Collect an aliquot of
the supernatant solution at the previously determined time, in which the balance was established.
Filter and quantify the API through a method previously validated and indicative of stability. Record
the pH of the solution at the end of the experiment. There must not be a variation superior to 0.1 unit
between the pH measured in the beginning and at the end of the test. The medium pH must not be
adjusted during the procedure, since it may displace the dissociation equilibrium, changing the
solubility.
Calculations
Determine the solubility in mg/mL. Calculate the relative standard deviation (RSD) between the
solubility results obtained. The RSD results must be of no more than 5% between replicates of each
assay condition.
For classification of API concerning solubility, according to the BCS, it is necessary to calculate the
ratio between the maximum dose API by single administration described on the package insert
This translation does not replace the portuguese version.
Brazilian Pharmacopoeia, 6th edition IG8.9-00
(em mg) and its solubility (in mg/mL). With results below or equal to 250 mL, the API is classified
as having high solubility. Results higher than 250 mL indicate that the API has low solubility.
The analytical method must be validated for quantification of API in the three mediums used. For
such, it is necessary to observe the suitability of results from the following validation parameters:
linearity, precision, accuracy, limit of quantification and selectivity. It is also necessary to confirm
that the method proposed is capable of quantifying the API regardless of possible degradation
products originated during the experiments.
ASSAYS
The use of microbiological assays is very important in the quality control for products and
pharmaceutical ingredients, since microbial contamination may cause changes to their physical and
chemical properties and affect the product quality and the consumer safety.
Despite being efficient, simple and having low cost, traditional microbiological assays present some
limitations, such as delayed result, low selectivity of culture medium, and variability of biological
response from microorganisms.
In the attempt to overcome the deficiencies presented in traditional tests, alternative microbiological
assays have been developed. These tests may provide an improvement in the quality of tests, higher
sensitivity and faster results, allowing corrective actions to be taken early.
There are major advantages with the application of these tests, but it is necessary to have adequate
understanding of their potential for application and a prior and judicious validation duly documented.
In alternative tests, there are specific principles and knowledge requiring adequate qualification from
the professionals who will apply them. When selecting the test, it is necessary to consider its
applicability and the compatibility with the product to be analyzed.
This chapter has the purpose of presenting the main alternative microbiological assays, their
applications and general criteria for validation. The intention is not to recommend the assay to be
used nor to present an exhaustive list, but to help in the selection and validation process.
TYPES OF TESTS
The alternative microbiological tests may be grouped into quantitative, qualitative and identification.
Quantitative tests are those used when there is the goal of determining the amount of microorganisms
in a sample. With qualitative tests, the presence or absence of microorganisms is presented. On the
other hand, identification tests are used with the goal of characterizing the microorganism present.
MAIN METHODS
Methods based on growth
The alternative microbiological methods based on growth technologies are different from
conventional methods since they use biochemical or physiological parameters or artifacts from them
for detection of microbial growth. One of the advantages of these methods in comparison with
traditional methods is the ability to process simultaneously a large number of samples and obtain
results in a lower time. Examples of alternative microbiological method based on growth
technologies:
Electrochemical methods Microorganisms that multiply in a specific culture medium produce highly
charged ionic metabolites, from weakly charged organic nutrients, leading to modification of
electrical properties of these media. Such changes in impedance (measured by conductance or
capacitance) are monitored with electrodes in contact with the culture medium. The measurable
endpoint is the necessary time to detect a change in the initial impedance, being inversely proportional
to the size of the inoculum. For molds and yeasts, which produce only small changes in electric
impedance, making an indirect conductance measurement is common, using a potassium hydroxide
reservoir. The direct capacitance measurement can also be made. The automated detection with
generation of electronic data and mapping of impedance variation reflects the microorganism growth
curve, allowing to reduce the test duration to 48 hours.
Bioluminescence. Adenosine triphosphate (ATP) is present in all living cells and its detection is an
indicator of the presence of viable microorganisms. The test consists of extracting ATP from
microbial cells, followed by the quantitative or qualitative test using the enzyme system
luciferin/luciferase, and measuring the light generated by a luminometer, or a camera with coupled
charging device The relative light (measured in relative light units – RLU) is directly proportional to
the amount of ATP present in the atmosphere and depends on factors such as sensitivity of reagents
and number of microorganisms present. In the case of a reduced number of microorganisms in the
sample, that is, less than 102 – 103, there may be the need for a system pre-incubation step. It may
also be necessary to enhance the sample preparation steps to reduce the presence of non-microbial
ATP, employing, for example, a sample pre-treatment with enzymes apyrase or somase. The ideal
extraction of ATP must be fast and active, in order to avoid its degradation, thus ensuring efficient
parameters of sensitivity and reproducibility. Since the reaction that generates bioluminescence is of
enzymatic nature, it is subjected to interferences from products that may inhibit or reduce the
enzymatic activity, and must be investigated during the process validation.
Use of chromogenic substrates. Chromogenic substrates are frequently used to detect the presence
of specific enzymes in the identification of microorganisms, employing manual or automated
methods. Liquid or solid culture media with chromogenic substrates are used to reveal specific
enzyme activities for detection and differentiation of microorganisms. In these particular media,
substrates defined are introduced in the formulation and hydrolyzed by the specific cell enzyme of a
determined bacterium or fungus during growth. These substrates are selected according to the enzyme
activity and are related to the presence of colored indicators. These products allow better
differentiation of colonies in mixed cultures, being easy to use and interpret. Additionally, the
response time is lower, because the growth and identification of the microorganism are simultaneous.
However, the validation of culture media must be made carefully to guarantee a combination of
selectivity, specificity and robustness. The signal quality is based not only on the judicious selection
of enzymes to be assessed, because they may be present in different genera, but also in the
physicochemical characteristics of the medium, such as pH.
Methods based on direct viability measurement are fast and independent from microbial proliferation.
They are based on the use of colorants for biochemical components of microbial cells or fluorescence
obtained by enzyme cleavage of fluorogenic substrates in microorganisms with functional cell walls.
Solid phase cytometry. In solid phase cytometry, a fluorophore viability indicator is used, retained
in the cytoplasm of microorganisms with intact membrane. The conjugated non-fluorescent substrate
requires intracellular enzyme activity to be cleaved and release the fluorescent portion. An automatic
laser reader allows reading fluorescent cells and appropriate software programs allow the
differentiation between viable cells and fluorescent particles. The differentiation between viable and
non-viable cells is based on the presence or absence of esterase activity and in the intact cell
membrane. This technique uses membrane filtration to separate possible microbial contaminants from
filtrable samples and subsequent labeling of cells retained with the viability substrate. This is
hydrolyzed by non-specific esterase enzymes in the cytoplasm of metabolically active
microorganisms, releasing free fluorophore. Before labeling, a counterstain can be added to minimize
the background fluorescence, and a pre-incubation step may be necessary for activation of spores or
recovery of stressed or fastidious microorganisms. The filtering membrane is scanned by a laser
system from the cytometer and the fluorescent light is detected by photomultiplier cells.
Flow cytometry. The flow cytometry allows to detect microorganisms suspended in a liquid medium.
The labeling and detection mechanisms are similar to the solid phase cytometry, but the sample does
not need to be filtered. The microorganisms labeled by the non-fluorescent viability indicator can be
detected in suspension, when passing through a flow cytometer. The sample labeled is injected in a
quartz flow cell and passes through an excitatory laser beam for detection of microorganisms. The
flow cytometry also provides quick results, but is less sensitive than the solid phase cytometry. To
improve the performance, a prior step of incubation in culture medium can be conducted, which
would make the method based on growth.
Direct epifluorescence. In this method, as well as in solid phase cytometry, the samples are filtered
and stained with a fluorescent viability indicator, such as the acridine orange stain or 4’,6-diamidino-
2-phenylindole (DAPI). The microorganisms are detected by epifluorescence microscopy.
Epifluorescence allows the fast detection of microorganisms and its sensitivity depends on the filtered
volume and number of fields examined. Systems with image analysis increase the method usefulness.
The direct epifluorescent filter technique is applicable to liquid products and fluids with low viscosity,
and can also be applicable to particulate products diluted in advance. A modification of this method
employs sampling using adhesive sheet to collect surface cells, staining on the sheet and subsequent
direct observation in epifluorescence microscope.
They encompass methods on which the expression of some cell components provides the indirect
measure of microbial presence. There is a high degree of specificity and they allow quick results. A
high number of cells may be necessary.
Phenotypical
Immunologic. With immunologic methods, microorganisms are detected and quantified through
antigen-antibody interaction. They are useful for the identification of specific microorganisms or
unique cell determinants. The antigen-antibody interaction may be related to phenomena
The ELISA (Enzyme-Linked Immunosorbent Assay) test is a labeling technique to indicate the
presence or absence of an antibody or antigen. In this technique, there is at least one antibody with
specificity for an antigen in particular. The sample with the antigen is immobilized in a solid support
(usually a polystyrene microtitration plate). After the antigen immobilization, the antibody connected
to an enzyme is added and forms a complex with the antigen. Then, an enzyme substrate is added,
producing a visible signal, usually by change of color, that indicates the presence of antigen in the
sample.
The immunologic methods depend on the unique expression of specific identifiers. Therefore, they
do not indicate necessarily the presence of microorganisms. Immunoassays are simple, cheap and can
be used for qualitative and quantitative analysis.
Fatty acid profile. The cellular fatty acid profile is unique and stable, with a high level of
homogeneity and reproducibility within a taxonomic group. The differentiation and identification of
a wide variety of microorganisms can be made through the amount and types of fatty acids extracted
from the microbial sample. Fatty acids from the ramified chain are common in many Gram-positive
bacterial, while Gram-negative bacteria are predominantly comprised of linear chain fatty acids. The
isolate is cultivated in a standard culture medium, and the use of cultures with 22 to 26 hours is
important, to ensure that the cells are in the exponential growth phase. Fatty acids are extracted by
saponification process, followed by methylation to convert them in the respective methyl ester
(FAME – Fatty Acid Methyl Ester), which is extracted from the aqueous phase by the use of organic
solvent, and the resulting extract is analyzed by high-resolution gas chromatography. The profile of
fatty acid methyl esters extracted from a sample is compared with known isolates in a database. This
technique requires a high level of standardization, including culture media, incubation temperature
and operation conditions.
When matter absorbs radiation in the infrared region, there are changes in the vibrational level of
chemical bonds. The wavelengths in which these transitions occur are characteristic to each functional
group. Thus, it is possible to elaborate tables that allow the identification of molecules in samples
which composition is unknown, with the construction of specific databases that allow the
identification of microorganisms. The microorganism researched must be isolated in a cultivation
medium, collected, analyzed in Fourier-transform infrared spectrometer and the spectrum obtained
must be compared with a database for identification.
Mass spectrometry. The mass spectrometry allows the determination and identification of chemical
structures through mass assessment and ionic charge. It is a technique that can be used in the analysis
of biomolecules and large organic molecules, such as DNA, proteins, peptides, sugars and polymers.
and without electric field, to measure their time of flight, proportional to the molecule’s molar mass,
to the detector. The MALDI-TOF technique is used for fast identification of microorganisms that are
treated as complex chemical entities. The microbial culture is placed on a plate well and covered with
solvent matrix. The plate is exposed to laser, causing desorption of ionized cell components, which
travel the tube toward the mass detector. The detection time differs for each molecule and the full
analysis of each microbial cell provides a mass spectrum from the macromolecules. The detector
signal is captured as a single fingerprint for each microorganism. The spectrum obtained is compared
in a database.
Preliminary differentiation tests, such as Gram staining, allow deciding for the adequate use of the
series of biochemical and/or enzymatic reactions. Usually, microbial suspensions are tested using
biochemical test kits. These assays require pure colonies with up to 3 days of cultivation. The system
is easy to operate, but the result interpretation may be subjective. The result can be quick, depending
on the system used and on the microorganism investigated.
Genotypic
Amplification of nucleic acids. The techniques that employ the amplification of nucleic acids may
allow the identification of microorganisms from the exponential increase of a specific fragment of
nucleic acid. Several methods can be employed in the analysis of fragments: size, specific sequence,
reamplification with a second pair of primer, or specific detection by hybridization with fluorescent
probe. The method selection must consider the purpose of the analysis. The use of DNA as marker
may detect non-viable microorganisms that also have DNA, while mRNA is quickly degraded in non-
viable microorganisms, being considered a good marker for viability.
Fingerprints. This technique characterizes and identifies microorganisms in subspecies level, using
fragments of restriction of nucleic acids from bacterial and fungal genomes. From a pure and lysed
culture, the DNA is extracted and fragmented by restriction enzymes. DNA fragments are separated
by size through electrophoresis, viewed and compared with standards obtained from known species.
Ribotyping is a typical example of this technique. There are also methods based on PCR fingerprint
with primers that bond to different sites of the microbial genome, creating amplified fragments with
a characteristic size distribution. For employing this technique, it is necessary to use pure colonies.
The main goal intended with this item is to provide general guidelines for validation of alternative
microbiological methods, to demonstrate the non-inferiority between this and the traditional method.
Before the formal validation, a critical assessment of the alternative method one wants to validate
must be made. Some aspects must be verified, such as the compatibility of the alternative method
with the product and its suitability to routine. Additionally, it is necessary to assess the production
process to identify possible sources of microbial contamination and their microbiological profile. This
assessment must take into account, for example, microorganisms isolated from raw materials, control
in process or in the process development, environmental monitoring, as well as microorganisms of
slow growth and contaminant microorganisms common to the product, reported in literature. This
assessment will be important to determine the most adequate samples and identify the types and
number of microorganisms associated to the process, which must be addressed in the validation of
the new method. Regardless of the new method to be validated, the equipment, when used, including
computer hardware and software, must be qualified/validated according to Good Practices. Some
alternative methods depend on the use of database. The extension of coverage by this database must
be described in the goal intended with the validation. According to the nature of the microbiological
assay, the validation parameters follow Table 1.
The spectrum of microorganisms selected for validation of the alternative method and for
demonstration of non-inferiority in relation to the traditional method must be carefully justified. The
microorganisms described in general methods, specifically on items Microbiological assays for non-
sterile products (5.5.3.1), Table 1, or Microbiological assays for sterile products (5.5.3.2), Table 1,
are a reference to be followed. Additionally, it is recommended to use microbial isolates that are
recurrent to the sample tested.
In the validation of the non-inferiority method, the non-inferiority in relation to the traditional method
must be proven. With this attribute, the purpose is to demonstrate that the alternative method is not
less sensitive and is as effective as the traditional method, considering a tolerance margin established
in advance, named non-inferiority margin.
The non-inferiority of an alternative method (A) in relation to the traditional method (T) is established
from the construction of bilateral, CI 95%, or unilateral, IC 97.5%, confidence intervals, where the
upper limit for the difference T – A is smaller than the margin (M).
The null (H0) and alternative (H1) hypotheses, related to non-inferiority studies, are, respectively:
In the demonstration of non-inferiority, the same types of products and the same microbial
suspensions used in the assessment of alternative method must be submitted to the traditional method.
However, it is necessary to pay attention to tests which sample contamination profile is zero. In these
cases, the demonstration of non-inferiority with the use of contaminated samples is more appropriate.
For qualitative tests, the demonstration of non-inferiority must be made for the parameter Limit of
Detection. For quantitative tests, the demonstration must be made for Limit of Detection, Limit of
Quantification, Accuracy and Precision. In the case of identification tests, the demonstration of non-
inferiority must be made for the parameters of Accuracy and Precision.
PARAMETERS
Specificity
The specificity, in the context of non-selective microbiological methods, represents the method’s
capacity to promote a positive response for the different microorganisms one expects to be present in
a sample. When it comes to selective microbiological methods, the demonstration of specificity also
involves obtaining negative results for the microorganisms that are not of interest for the method. In
both cases, when it comes to methods which interpretation of result through direct reading of
microbial growth is not obtained, it is also necessary to demonstrate that components from the matrix,
contaminants or foreign materials are not capable of promoting false positive or false negative results.
For this parameter, it is important to test the highest possible number of microorganisms.
Limit of detection
The limit of detection is the lowest number of microorganisms in a sample that can be detected under
the experimental conditions established. It refers to the number of microorganisms present in the
original sample before any dilution or incubation.
The alternative method and the traditional method must be assessed using an inoculum with a low
concentration of microorganisms. The concentration of this inoculum must be adjusted along the
study so that at least 50% of the results obtained by the traditional method are positive. A minimum
number of five replicates must be used for each concentration selected.
The non-inferiority with the traditional method must be demonstrated through statistical comparison
of the number of positive and negative results obtained between the two methods. The Chi-squared
test can be used for this purpose. The limit of detection achieved must be compatible with the purpose
proposed for the method, such as, for example, there must be significant confidence for a method
proposed for sterility analysis to be capable of detecting 1 CFU in the sample to be tested.
Limit of quantification
The limit of quantification is the lowest number of microorganisms that can be determined with
precision and accuracy under the experimental conditions established. This parameter must be
determined with, at least, five concentrations within the work range for each microorganism and in
five replicates for each concentration. Alternatively, results from linearity and accuracy can be used
and, in this case, the limit of quantification corresponds to the lowest concentration found in the
interval.
Accuracy
Accuracy represents the proximity of results obtained experimentally in relation to the results
expected for microbial dilution used or the ones obtained by the traditional method. Generally, it is
expressed as the percentage of recovery of microorganisms. The accuracy can be demonstrated by
employing microbial suspension with concentration in the upper limit of the work interval defined
for the method. From this suspension, serial dilutions must be prepared covering the entire work
range, which must be overlapped with the one from the traditional method. The original suspension
and its dilutions must comprise the different microbial concentrations. This parameter must be
determined with, at least, five concentrations within the work range for each microorganism and in
five replicates for each concentration. The percentage of recovery of the alternative method must be
located on (100 ± 30)%.
To demonstrate the non-inferiority, in the two methods, it is not necessary to obtain statistically equal
degrees of recovery. The verification that the results obtained with the alternative method meet the
acceptance criterion is sufficient most of the time. However, the results obtained with the alternative
method can be compared with results with the traditional method to determine which one is more
accurate. For this, the data normality must be verified through a statistical test for this purpose. Once
the data normality is found, the Snedecor F-test can be executed to verify the equality of variances.
If they are equal, the comparison of recovery averages can be made by Student’s t-test or by Analysis
of Variance (ANOVA).
Precision
Precision is the degree of concordance between individual test results when the procedure is applied
repeatedly in homogeneous suspensions of microorganisms including the work range. It is usually
expressed as the standard deviation or relative standard deviation (coefficient of variation) of the
results obtained. This parameter can be demonstrated by employing microbial suspension with a
defined concentration and, from it, serial dilutions must be prepared.
The precision must be determined with, at least, two concentrations, one located in the limit of
quantification and the other, in the limit of specification of the product for each microorganism and
in 10 replicates for each concentration. For assessment of intermediate precision, the experiment must
be repeated in a different work day.
For identification tests, the precision must be determined with 10 replicates in different work days.
In general, values lower than 30% for the coefficient of variation demonstrate an acceptable precision
for the methods. However, the non-inferiority between the alternative method and the traditional
method must be demonstrated through an appropriate statistical test.
Linearity
Linearity is the method’s capacity to produce results that are proportional to the concentration of
microorganisms present in the sample within a certain interval.
This parameter must be determined with, at least, five microbial concentrations for each
microorganism and in five replicates for each concentration.
It is necessary to be aware of limitations from existing methods, both for the alternative method and
for the traditional method, so that the concentrations used do not produce overlapped results.
Therefore, adjustments to the number of concentrations can be made if the work limit is restricted.
The linearity assessment can be conducted by calculating the square of the correlation coefficient, r2,
from a linear regression analysis of the data generated. Despite the fact that the correlation coefficient
does not provide an estimate of linearity, it is commonly applied to give an idea of relation. The
alternative method must not have a r2 value lower than 0.95.
Interval
The interval is the range between the lowest and the highest concentration of microorganisms that
have been determined with precision, accuracy and linearity following instructions in the method.
The interval is determined from precision, accuracy and linearity studies.
Robustness
The robustness is the degree of reproducibility of results obtained in the test by analysis of the same
sample with variations of the normal test conditions, such as instruments, reagent lots and
laboratories. It enables establish the method feasibility under deliberate variations in operating
parameters.
MAIN APPLICATIONS
The selection of the alternative microbiological method requires knowledge about its scientific base
and must consider the purpose of the test and its compatibility with the product to be analyzed.
Guidelines/suggestions for applications of the methods available are listed on Table 2.
(SI) UNITS
The international system has seven base units, used as a reference in all measurements and listed on
Table B.1
All other quantities are described as derived quantities and measured as derived units. Table B.2 lists
some of these derived quantities.
Notice that the refractive index and the relative permeability are examples of dimensionless
quantities, for which the SI unit is the number 1 (one), although this unit is not written.
Some derived units receive a special name, which is simply a compact form of expression of
combination of base units that are frequently used. For example, joule, with the symbol J, is by
definition equal to m2 kg s-2. There currently are 22 special names for units approved for used on the
SI, and they are listed on Table B.3.
Although hertz and becquerel are equal to the inverse second, hertz is used only for cyclic phenomena,
and becquerel is used for stochastic processes in radioactive decay.
The Celsius temperature unit is degree Celsius, °C, which is equal in magnitude to kelvin, K, the
thermodynamic temperature unit. The Celsius temperature quantity t is related to the thermodynamic
temperature T by the equation t/oC = T/K – 273.15.
Sievert is also used for the quantities: directional dose equivalent and individual dose equivalent.
The final four special names of units on Table B.3 were adopted specifically to protect measurements
related to human health.
For each quantity, there is only one SI unit (although it may be frequently expressed in different
manners, by the use of special names). However, the same SI unit can be used to express values from
several different quantities (for example, the SI unit for the J/K ratio can be used to express both the
thermal capacity and the entropy values) Therefore, it is important to not use the unit alone to specify
the quantity. This applies both to scientific texts and to measurement instruments (that is, the output
reading of an instrument must indicate the quantity measured and the unit).
Dimensionless quantities, also known as dimension one quantities, are usually defined as the ratio
between two quantities of the same nature (for example, the refractive index is the ratio between two
speeds, and relative permeability is the ratio between the permeability of a dielectric medium and the
permeability of vacuum). Therefore, the unit of a dimensionless quantity is the ratio between two
identical units of the SI, and therefore it is always equal to (1). However, when expressing the values
of dimensionless quantities, the unit 1 (one) is not written.
Table B.4 – Multiples and submultiples from the SI – Prefixes and symbols.
Quantity Unit Symbol Relation with SI
Time Minute min 1 min = 60 s
Hour h 1 h = 3600 s
Day d 1 d = 86400 s
When prefixes are used, the prefix name and the unit name are combined to form a single word and,
similarly, the prefix symbol and the unit symbol are written without spaces, to form a single symbol
that can be raised to any power. For example, it is possible to write: kilometer, km; microvolt, μV;
femtosecond, fs; 50 V/cm = 50 V(10-2 m)-1 = 5000 V/m.
When the base units and the derived units are used without any prefix, the resulting set of units is
considered coherent. The use of a set of coherent units has technical advantages. However, the use of
prefixes is convenient because it avoids the need to employ 10n factors to express values of vary large
or very small quantities. For example, the length of a chemical bond is more conveniently expressed
in nanometers, nm, than in meters, m, and the distance between London and Paris is more
conveniently expressed in kilometers, km, than in meters, m.
Kilogram, kg, is an exception because, although it is a base unit, its name already includes a prefix,
for historical reasons. Multiples and submultiples of kilogram are written by combining prefix with
gram: it is written milligram, mg, not microkilogram, μkg.
Although some non-SI units are still widely used, others, such as minute, time and day, as time units,
will always be used, because they are deeply ingrained in our culture. Others are used for historical
reasons, to meet the needs from groups with special interests, or because there isn’t a convenient SI
alternative.
Scientists must have the freedom to use non-SI units if they consider them more adequate to their
purpose. However, when non-SI units are used, the factor of conversion to SI must always be
included. Some non-SI units are listed on Table B.5, with their factor of conversion to SI.
The unit symbols start with an upper-case letter when the unit is named after a person (for example,
ampere, A; kelvin, K; hertz, Hz; coulomb, C). In the other cases, they always start with a lower-case
letter (for example, meter, m; second, s; mole, mol). The symbol for liter is an exception: the upper-
case letter is used to avoid confusion between the lower-case letter l and the number 1 (one). The
symbol for nautical mile is presented here as M; however, there is no general agreement around any
symbol for nautical mile.
Table B.6 lists other examples of units outside the SI and still being used, but which must be avoided.
When mentioned in a document, it is worth indicating their equivalence to a SI unit.
The unit symbols are printed in roman (upright) font, regardless of the font used in the rest of the text.
They are mathematical entities, not abbreviations. They are never followed by a dot (except at the
end of a sentence) or an “s” to form the plural. It is mandatory to use the correct form for the unit
symbols, as illustrated by examples presented in the full publication by the SI. Sometimes, the unit
symbols may have more than one letter. They are written in lower-case letters, except the first letter
when they are named after a person, which is then written in upper-case. However, when a unit’s
name is written in full, it must start with a lower-case letter (except in the beginning of a sentence),
to differentiate the unit’s name from the person’s name.
When writing the value of a quantity, as the product of a numeric value and a unit, both number and
unit must be treated by the ordinary algebra rules. For example, the equation T = 293 K can be also
written as T/K = 293. This procedure is described as the use of calculation of quantities, or algebra of
quantities. Sometimes, this notation is useful to identify the
header of table columns, or the denomination of chart axes, so that entries on the table or the
identification of points over the axes are simple numbers.
In the formation of products or quotient of units, the normal algebra rules apply. In the formation of
products of units, it is necessary to leave a space between the units (alternatively, it is possible to raise
a multiplication dot on half the row’s height).
In the formation of numbers, the decimal separator can be a dot or a comma, according to the
appropriate circumstances. For documents in English, the dot is usual, but in Brazil and form many
Continental Europe languages and in other countries, the comma is more commonly used.
When the number has many digits, it is usual to group them in blocks of three, before and after the
dot, to facilitate reading. This is not essential, but done frequently, and in general it is very useful.
When this is done, the three-digit groups must be separated by only one narrow space; a dot or a
comma must not be used between them. The uncertainty of the numeric value of a quantity may be
conveniently expressed, making evident the uncertainty of the last significant digits, between
parentheses, after the number. Example: 123 456.789 0
For additional information, please refer to the website of BIPM http://www.bipm.org or the full
Publication of the SI, 8th edition, available on the website http://www.bipm.org/en/si.
CHROMATOGRAPHY
Solvents for chromatography and their characteristics are listed on Table C.1.
ANNEX D – ALCOHOLOMETRY
12B