EP1327674B1 - Use of a detergent concentrate and method for cleaning surgical instruments - Google Patents

Abstract

Detergent concentrate contains not less than 10 weight percent (wt.%) alkanolamine(s), not less than 3 wt.% chelant(s) and enzyme(s).

Description

The invention relates to a use for cleaning and / or disinfecting medical instruments and / or apparatus as well as corresponding cleaning methods.

Surgical instruments as well as other medical devices are usually cleaned in the hospital using alkaline detergents and then disinfected chemically or thermally. Such strong alkaline agents can be aggressive to sensitive surfaces. Surgical instruments contaminated with blood are often stored immediately after use, for example, in an aldehyde-containing disinfectant solution and initially remain there until they are cleared for cleaning in the dishwasher. The blood is coagulated by the disinfectant and the protein components contained in the blood denatured by the aldehydic disinfectant. Such particularly stubborn blood residues are often only to be removed by alkaline-active chlorine-containing cleaning agents. The oxidizing Aktivchlorkomponente causes the decomposition of the denatured protein components. Other constituents of disinfectants such as, for example, iodine can form residues that are difficult to remove.

The alkaline-active chlorine-containing cleaners have the disadvantages that they contain hazardous substances requiring labeling, that in their handling special precautions to protect the operator are required and that they represent an undesirable environmental impact in the wastewater.

Out US-A-4,243,546 . EP-A-0 481 663 and EP-A-0 730 024 enzyme-containing detergents are known, which in particular can degrade blood proteins enzymatically.

EP-A-1 021 519 discloses an enzyme-free detergent concentrate for cleaning surgical instruments. As a disadvantage of the enzymatic cleanser is mentioned there that the enzyme activity can subside upon prolonged storage.

The invention has for its object to provide a use of a cleaning concentrate, which has a good cleaning effect against occurring in hospital mixed impurities such as coagulated blood and disinfectant residues and the build-up of residual impurities such as protein or limescale on the cleaned instruments and the dishwasher used itself counteracts.

1. a) mindestens 11 Gew.-% wenigstens eines Alkanolamins,
2. b) 3 bis 10 Gew.-% wenigstens einer Aminopolycarbonsäure und/oder deren Salze als Komplexbildners,
3. c) wenigstens ein Enzym.

und wobei das Reinigungsmittelkonzentrat in gebrauchsfertig verdünnter wässriger Lösung einen pH-Wert von 9 bis 11 aufweist.Therefore, an object of the invention is the use of a detergent concentrate for the mechanical and / or disinfection of medical and / or surgical instruments and / or apparatus, wherein the detergent concentrate contains:

1. a) at least 11% by weight of at least one alkanolamine,
2. b) 3 to 10% by weight of at least one aminopolycarboxylic acid and / or salts thereof as complexing agent,
3. c) at least one enzyme.

and wherein the detergent concentrate in ready-to-use dilute aqueous solution has a pH of 9 to 11.

1. a) Aufbringen einer 0,5 bis 100%igen wäßrigen Lösung eines obengenannten Reinigungsmittelkonzentrats,
2. b) Einwirkenlassen der Lösung bei einer Temperatur von Raumtemperatur bis zur Siedetemperatur der Lösung,
3. c) Nachspülen.

Another object of the invention is a method for cleaning medical and / or surgical instruments and / or apparatus with the following steps:

1. a) application of a 0.5 to 100% strength aqueous solution of an abovementioned cleaning agent concentrate,
2. b) exposing the solution to a temperature of from room temperature to the boiling point of the solution,
3. c) Rinse.

The invention is based on the surprising finding that the combination of alkanolamine, complexing agent and enzyme results in a storage-stable cleaning agent concentrate which can remove dried, preheated or denatured blood residues of surgical instruments by automated cleaning, for example. The iodine residues often originating from disinfectants or their reaction products with blood constituents are also removed. A particular advantage of the invention is that the structure of protein and / or alkaline earth salt deposits or mixtures thereof is avoided on instruments and the interior of the dishwasher; Such deposits build up when using detergent concentrates The prior art often after many rinse cycles on and can not or only with difficulty be removed. The detergent concentrate surprisingly avoids such a deposit formation or removes existing deposits from cleaning processes of the prior art again.

Essential for this success is the combination of alkanolamine, complexing agent and enzyme. It is surprising that a storage-stable, enzyme-containing cleaning agent concentrate can be produced with the complexing agent content of at least 3% by weight required according to the invention. In the prior art, it is believed that calcium ions must be present to stabilize enzyme preparations. Since complexing agents and in particular chelating agents complex alkaline earth metal ions, it is actually to be expected that the addition of a correspondingly large proportion of the complexing agent impairs the stability of the enzyme composition. Surprisingly, this is not the case.

The enzymes contained in the concentrate may in particular be amylases or proteases. Proteolytic enzymes are preferred. The amount of these proteolytic enzymes is preferably between 0.005 and 0.1 Anson units per g of concentrate.

The alkanolamine content according to the invention is preferably between 11 and 40 wt .-%, further 11 and 20 wt .-%, more preferably 11 and 15 wt .-%.

wobei R₁ eine Hydroxyalkylgruppe mit 1 bis 6 C-Atomen darstellt und wobei R₂ und R₃ unabhängig voneinander die genannte Hydroxyalkylgruppe oder Wasserstoff darstellen.The alkanolamines used preferably have the structure:

wherein R _{1 represents} a hydroxyalkyl group having 1 to 6 C atoms, and wherein R ₂ and R ₃ independently represent said hydroxyalkyl group or hydrogen.

Particular preference is given to mono-, di- and / or triethanolamine.

The content of aminopolycarboxylic acid and / or its salts as complexing agent is preferably between 4 and 8 wt .-%, more preferably between 5 and 7 wt .-%.

The complexing agents serve to soften the water and can improve the cleaning action against lime soaps by complexing alkaline earth ions.

The concentrate may contain nitrilotriacetic acid and / or a salt of this acid, more preferably its trisodium salt. Surprisingly, this addition of NTA causes particularly good removal of lime soap even at low pH values in the range from 6 to 9. The addition of NTA is also advantageous if the concentrate is to be prepared with a solution containing very mineral (hard) water to a ready-to-use solution.

The detergent concentrate has in ready to use dilute aqueous solution to a pH of 9 to 11, preferably 9.5 to 10.5. Ready-to-use dilution means according to the invention a 0.5-100% strength aqueous solution of the cleaning agent concentrate. If pH values of a dilute solution of the cleaning agent concentrate are measured in the context of the present application, demineralized water (demineralized water) is used as the solvent. If the concentrate is made into a ready-to-use solution with ordinary tap water, slightly different pH values may result, depending on the nature of this water.

The adjustment of the pH to the stated range is preferably carried out by addition of acids and / or suitable buffer systems. Preferably, the addition of at least one organic acid is selected from the group consisting of mono-, di- or tricarboxylic acids having 2 to 6 carbon atoms. Among these acids are preferably citric acid, tartaric acid, Malic acid, lactic acid, glycolic acid, glyoxylic acid, succinic acid, adipic acid and glutaric acid. Citric acid is particularly preferred. The acids are added to the concentrate preferably in an amount of 0.5 to 15% by weight, more preferably 2 to 10% by weight. Some of these organic acids mentioned such as citric acid are simultaneously complexing agents in the context of the invention.

The corrosive effect of complexing agents such as NTA on anodized aluminum surfaces and the like can be reduced or completely avoided by adding at least one mono- and / or diester of phosphoric acid with aliphatic alcohols of chain length C ₁ to C ₂₂ and / or aliphatic diols and / or aliphatic polyols of chain length C ₂ to C ₂₂ . Particularly preferred is a diester of phosphoric acid with butanol on the one hand and ethylene glycol on the other. This ester is commercially available under the name Hordaphos® MDGB. According to the invention, this gives a good cleaning effect even when using hard water and still a gentle action on exloxierte aluminum surfaces.

Conventional preservatives may be added to the concentrate, for example p-hydroxybenzoic acid or its methyl ester, 5-bromo-5-nitro-1,3-dioxane, salicylic acid, 2-naphthyl-mN-dimethylthiocarbanilate, 5-chloro-5-methyl-4 -isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one and mixtures of the latter two compounds. A preferred preservative is p-hydroxybenzoic acid or its methyl ester. With the help of these preservatives microbial and fungal infestation of the detergent concentrate can be avoided.

If necessary, conversion aids (solubilizers) may be added, such as, for example, sodium cumene sulfonate, sodium toluene sulfonate, sodium xylene sulfonate, urea, glycols, in particular polypropylene glycols and polyethylene glycols, methylacetamide and fatty alcohols, such as cetyl alcohol.

The list of possible ingredients is not exhaustive. In addition, wetting agents, emulsifiers, antifoaming agents or the like may be added, for example. For example, the addition of N-acylglutamate as wetting agent is advantageous. Conventional ionic, nonionic or amphoteric surfactants may also be added.

The machine cleaning takes place without human intervention during an automatic program sequence, in particular in a conventional instrument dishwasher. The term "cleaning and / or disinfection" is intended to express that the concentrate can be used both in the combination of cleaning and disinfection in a single process step as well as in program sequences in which a cleaning step is followed by a separate disinfection step. In this case, the concentrate is usable in both of these steps.

In the inventive method for cleaning medical and / or surgical instruments and / or apparatus The application of the aqueous solution of the cleaning agent concentrate is preferably done by spraying, but may, for example, be done by dipping or pouring. The concentrate can be sprayed in a very high concentration, possibly pure, as a fine mist and initially act in this high concentration or pure. Subsequently, if necessary, additional water can be applied to the instruments to be cleaned and the so diluted cleaning solution is circulated and applied, for example. By spraying again on the instruments to be cleaned.

The action defined in step b) may, after application of the cleaning solution, be applied at rest, i. without continuous application or spraying or mechanical agitation or agitation of the cleaning solution. Thus, for example, in particular highly concentrated cleaning solution can be sprayed on first, after spraying it is then allowed to act. However, the exposure period may also include sections in which the cleaning solution is continuously re-applied to the instruments and / or mechanically circulated or moved in any other way. Also advantageous is a combination of these two types of action, ie first, in particular, a highly concentrated cleaner solution at rest and then diluting the cleaner with water under continuous circulation and re-spraying.

The aqueous solution of the cleaning concentrate is advantageously applied as 0.5 to 20%, preferably as 0.5 to 10%, more preferably as 1 to 5% aqueous solution. During the exposure period, the solution of the concentrate can be further diluted by additional water but should not fall below a minimum concentration of 0.5%. It should be noted that all percentages are by weight.

The exposure in step b) is preferably carried out at room temperature to 55 ° C, more preferably at 35 - 50 ° C, particularly preferably at 40 - 50 ° C. Einwirktemperaturen of just over 40 ° C have been found to be particularly advantageous because on the one hand a good cleaning effect is achieved and on the other hand, the instruments to be cleaned are spared.

Advantageously, the exposure time in step b) is 2 s to 30 min, preferably 10 s to 10 min, more preferably 30 s to 5 min.

The list of procedural steps is not exhaustive. It may be provided additional pre- or Nachspülschritte, even more cleaning steps can be provided one behind the other. Furthermore, an additional disinfection step, which, for example, can be carried out by chemical disinfectants, is preferred. Particularly preferred is the implementation of a thermal disinfection. This can be done as a downstream step, for example. With deionized water at 85 ° C to 95 ° C, preferably 93 ° C. This water can be used simultaneously for rinsing according to step c), so that rinsing and thermal disinfection are combined with each other in this way. However, instead of using fresh water, the thermodisinfection step can also be carried out with the cleaning solution of step b) heated to the corresponding temperature.

Possibly. If so-called cycle belt washing machines are used, it is also possible to carry out several cleaning steps in succession with the cleaning agent concentrate according to the invention. It is, for example, possible to use in a cleaning step an ultrasonic immersion bath which is filled with an aqueous solution of the cleaning agent concentrate according to the invention.

The invention achieves a good cleaning effect, especially in areas of surgical instruments that are difficult to access, for example in the area of the joints of scissors.

The invention will be explained below with reference to exemplary embodiments.

example 1

A detergent concentrate according to the invention is prepared on the basis of the information in the following table. The amounts of the starting materials to be used are given in parts by weight. Triethanolamine 85% 15.0 Hordaphos® MDGB ¹ 1.0 citric acid 1.2 NTA trisodium salt 40% aqueous solution 15.0 Noramer® 2000 ² 0.4 Esperane 8.0 L 1.0 p-hydroxybenzoate 0.5 N-acyl glutamate 0.4 Water (desalted) 65.0 pH of the concentrate 9.7 pH of a 1% aqueous solution (in deionized water) 9.9 ¹ Diester of phosphoric acid with butanol and ethylene glycol ² complexing agents based on carboxylate / sulfonate-acrylic copolymers, Norso Haas SA, Verneuil, En Halatte, France

Example 2

In a single-tank dishwasher, the instruments to be cleaned are first pre-rinsed with cold water for 2 minutes at room temperature. Subsequently, the dishwasher is filled with cold water and the detergent concentrate according to Example 1 in a concentration of 5 ml / l added. The cleaning solution is heated to 50 ° C and held for 5 minutes at this temperature. During this time, the cleaning solution is circulated by flushing the instruments.

After pumping the cleaning solution is rinsed with cold water. Finally, demineralized cold water is allowed to run in and heated to 93 ° C for a 10 minute thermodisinfection. This thermal disinfection is also the final rinse. Finally, it is dried with hot air.

Claims (17)

1. Use of a cleaning agent concentrate for automated cleaning and/or disinfection of medical and/or surgical instruments and/or apparatuses, wherein the cleaning agent concentrate contains:

   a) at least 11% by weight of at least one alkanolamine,

   b) 3 to 10% by weight of at least one aminopolycarboxylic acid and/or salts thereof as complexing agent,

   c) at least one enzyme,

   and wherein the cleaning agent concentrate in an aqueous solution diluted ready-to-use has a pH of 9 to 11.
2. Use of the cleaning agent concentrate according to Claim 1, characterized in that it contains at least one proteolytic enzyme.
3. Use of the cleaning agent concentrate according to Claim 1, characterized in that it contains a proteolytic enzyme in an amount of 0.005 to 0.1 Anson units per g of concentrate.
4. Use of the cleaning agent concentrate according to one of Claims 1 to 3, characterized in that the alkanolamine content is 11 to 40% by weight, preferably 11 to 20% by weight, more preferably 11 to 15% by weight.
5. Use of the cleaning agent concentrate according to one of Claims 1 to 3, characterized in that the alkanolamine has the following structure:

   

   wherein R₁ is a hydroxyalkyl group having 1 to 6 carbon atoms and wherein R₂ and R₃ independently of one another are the said hydroxyalkyl group or hydrogen.
6. Use of the cleaning agent concentrate according to Claim 5, characterized in that it contains mono-, di- and/or triethanolamine.
7. Use of the cleaning agent concentrate according to one of Claims 1 to 6, characterized in that the content of complexing agent is 4 to 8% by weight, more preferably 5 to 7% by weight.
8. Use of the cleaning agent concentrate according to one of Claims 1 to 7, characterized in that it contains NTA and/or NTA salts.
9. Use of the cleaning agent concentrate according to one of Claims 1 to 8, characterized in that in aqueous solution diluted ready-to-use it has a pH of 9.5 to 10.5.
10. Use of the cleaning agent concentrate according to one of Claims 1 to 9, characterized in that it additionally contains at least one organic acid selected from the group consisting of mono-, di- or tricarboxylic acids having 2 to 6 carbon atoms.
11. Use of the cleaning agent concentrate according to Claim 10, characterized in that it contains at least one acid selected from the group consisting of citric acid, tartaric acid, malic acid, lactic acid, glycolic acid, glyoxalic acid, succinic acid, adipic acid and glutaric acid.
12. Use of the cleaning agent concentrate according to one of Claims 1 to 11, characterized in that it additionally contains at least one mono- and/or diester of phosphoric acid with aliphatic alcohols of chain length C₁ to C₂₂ and/or aliphatic diols and/or aliphatic polyols of chain length C₂ to C₂₂.
13. Process for the automated cleaning of medical and/or surgical instruments and/or apparatuses, characterized by the following steps:

    a) application of a 0.5 to 10% strength aqueous solution of a cleaning agent concentrate according to one of Claims 1 to 12,

    b) action of the solution at a temperature of room temperature up to boiling temperature of the solution,

    c) rinsing.
14. Process according to Claim 13, characterized in that the cleaning agent concentrate is applied in step a) as a 1 to 5% strength aqueous solution.
15. Process according to Claim 13 or 14, characterized in that the action in step b) proceeds at room temperature to 55°C, preferably at 35 to 50°C, more preferably at 40 to 50°C.
16. Process according to one of Claims 13 to 15, characterized in that the time of action in step b) is 2 s to 30 min, preferably 10 s to 10 min, more preferably 30 s to 5 min.
17. Process according to one of Claims 13 to 16, characterized in that it additionally comprises a thermal disinfection.