THE USE OF SYNTHETIC, NON-HORMONAL 21 -AMINOSTEROIDS, DERIVATIVES. METABOLITES AND PRECURSORS THEREOF IN THE TREATMENT OF VIRAL INFECTIONS
The present invention relates to the field of medicine generally, in particular to the treatment of infections, particularly viral infections.
The invention relates in particular to compositions and methods for the treatment of hepatitis viral infection, particularly hepatitis C (HCV) infection, formerly referred to as blood- borne non-A, non-B hepatitis virus (NANBV) infection. The synthetic, non-hormonal 21 - aminosteroids, derivatives, metabolites and precursors thereof outlined herein demonstrate the added ability of inhibiting hepatitis viral replication. The present invention ' is directed to therapeutic applications for synthetic, non-hormonal 21 -aminosteroids for their previously unappreciated, anti- hepatitis viral properties and their other therapeutic properties disclosed herein.
The acquired immune deficiency syndrome AIDS is a disease characterized by the loss of cell-mediated immunity. It is attributable to a virus that belongs to the family of retroviruses very prevalent in the animal kingdom and is called human immunodeficiency virus (HIV) . Disturbances of the entire immunodefense mechanisms result from the HIV infection, because above all the T4 or helper cells of the T system of the specific immunodefense are prevented from carrying out their role in the regulation of the immunoresponse. The HIV- induced T4 reduction results in the development of frequent and eventually fatal opportunistic infections caused by pathogenic organisms such as viruses, bacteria, protozoa's or fungi, normally harmless if there is a normal balance between the different T cell populations. It is thought that the immune dysregulation observed in individuals infected with HIV during progression to AIDS is accounted for by a shift from a T helper 1 (Th 1 ) to a less protective Th2-type cytokinin profile. It is the imbalance between the Th1 and Th2 that allows diseases that would ordinarily be contained or eliminated to progress sometimes lethally. There are urgent reasons for the development of more efficacious and safer treatments of viral and retroviral infections, as the number of patients infected with HIV or AIDS virus has significantly increased in recent years.
Anti-viral agents that inhibit replication of viruses have been known since the mid 1 980's. Hundreds of drugs are now available for inhibiting the replication of the HIV virus, however, their side effects are often so severe that treatment must be halted and HIV resistant strains quickly develop . Furthermore, conventional anti-HIV agents do not provide sufficient effect. There is a need for new, less toxic and more effective treatments that work against HIV. These new therapies would preferably be virus non-specific so as to prevent the promotion of resistant strains.
HCV is a transmissible disease distinguishable from other forms of viral- associated liver diseases, including that caused by the known hepatitis viruses, i.e. , hepatitis A virus (HAV), hepatitis B virus (HBV), and delta hepatitis virus (HDV), as well as the hepatitis induced by cytomegalovirus (CMV) or Epstein-Barr virus (EBV) . HCV was first identified in individuals who had received blood transfusions.
Chronic infection with hepatitis C virus is an insidious and slow-progressing disease having a significant impact on the quality of life. It can eventually result in cirrhosis of the liver, decompensated liver disease and/or hepatocelluar carcinoma.
Alpha interferon monotherapy is commonly used to treat chronic hepatitis C infection. However, this treatment is not always effective and sometimes results in intolerable side effects related to the dosage and duration of therapy. Ribavirin has been proposed as a monotherapy treatment for chronic hepatitis C infection (Thomas et al. MSLD Abstracts, Hepatology Vol. 20, NO. 4, Pt 2, Number 440, 1 994). However, this monotherapy treatment has usually been found relatively ineffective and has its own undesirable side effects. Combination therapy of alpha interferon and ribavirin has been proposed (Lai, et al. Symposium to the 9th Biennial Scientific Meeting Asian Pacific Association for the Study of the Liver. 1 994) . Preliminary results suggest that the combination therapy may be more effective than either monotherapy (Hayden F G, Schlepushkin A N. Combined interferon-a2, rimantadine hydrochloride, and ribavirin inhibition of influenza virus replication in vitro . Antimicrob Agents Chemother. 1 984;25:53-57) (Schvarcz R, Ando Y, S'nnerborg A, Weiland 0. Combination treatment with interferon alfa-2b and ribavirin for chronic hepatitis C in patients who have failed to achieve sustained response to interferon alone: Swedish experience. J Hepatology. 1 995;232 (Suppl 2): 17-21 ) (Brouwer J. T, Nevens F, Michielsen P, et al. What options are left when hepatitis C does not respond to interferon? Placebo- controlled Benelux multicentre retreatment trial on ribavirin monotherapy versus combination
with interferon. J Hepatol. 1 994;21 2 (Suppl 1 ) : S1 7. Abstract WP2/08) (Chemello L, Cavalletto L, Bemardinello E, et al. Response to ribavirin, to interferon and to a combination of both in patients with chronic hepatitis C and its relation to HCV genotypes. J Hepatol. 1 994;21 2 (Suppl 1 ) :S 1 2. Abstract GS5/29). However, no one has described methods using alpha interferon and ribavirin which eradicate HCV-RNA in any long-term, effective manner.
There is a definite need for a method for treating chronic hepatitis C infection which eradicates HCV-RNA in a long-term, effective manner. The demand for sensitive, specific methods of treating carriers of HCV and HCV contaminated blood or blood products is significant. Post-transfusion hepatitis (PTH) occurs in approximately 10% of transfused patients, and HCV accounts for up to 90% of these cases. The disease frequently progresses to chronic liver damage (25-55 %).
For the foregoing reasons there is a need to provide a composition for safer, treatments of viral and retroviral infections.
The correlation between synthetic, non-hormonal 21 -aminosteroids, specifically tirilazad mesylate and viral infections was not recognised prior to the work of the applicant. However, a great deal was known about synthetic, non-hormonal 21 -aminosteroids, tirilazad mesylate and viral infections, as separate fields in medicine and physiology. Accordingly the following provides information on each of these topics.
The present' invention relates to synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate that inhibit viral replication. It has been surprisingly found that synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate has potent anti-viral activity. Furthermore, the present invention relates to the metabolic derivatives (or metabolites) of synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate that also have anti-viral activity.
The present invention is directed to a method of treating an individual exposed to or infected with a virus comprising administering to that individual a synthetic, non- hormonal 21 -aminosteroids, preferably tirilazad mesylate, that inhibits, or prevents replication of said virus by interfering with the repliGative or other essential functions of the virus or the host cell.
The inventions objects include the provision of pharmaceutical formulations and synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate, which are suitable for making the formulations. Other objects are to provide methods to make and use the formulations.
In accordance with the present invention, a method is provided to treat or prevent a virus infection comprising administering to a subject an effective amount of one or more synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate.
The present invention also provides the use of one or more synthetic, non- hormonal 21 -aminosteroids, preferably tirilazad mesylate, for the manufacture of a medicament for treatment of a virus infection.
The present invention further provides the use of a composition comprising one or more synthetic, non-hormonal 21 -aminosteroids, for the manufacture of a medicament for treatment of a patient suffering from a virus infection.
The present invention also provides synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate for use in a method of treatment of a virus infection, said method comprising administering one or more synthetic, non-hormonal 24-aminosteroids to a subject.
According to one aspect of the invention, there is provided a substance or composition for use in a method of treatment of a viral infection, to prevent a future viral infection and/or to combat the effects of a present or future virus infection, said substance or composition comprising at least one synthetic, non-hormonal 21 -aminosteroid, and said method comprising administering to a patient in need thereof a prophylactically or therapeutically effective amount thereof.
According to another aspect of the invention, there is provided use of at least one synthetic, non-hormonal 21 -aminosteroid in the manufacture of a medicament to treat a viral infection, to prevent a future viral infection and/or to combat the effects of a present or future virus infection.
According to a further aspect of the invention, there is provided a method of regulating a dysregulated immune system, treating a viral infection, preventing a future virus
infection, combatting the effects of a present or future virus infection, or treating AIDS related syndromes, the method comprising administering to a patient in need thereof a prophylactically or therapeutically effective amount of a substance or composition comprising at least one synthetic non-hormonal 21 -aminosteroid.
In accordance with the objects the present invention provides an improved pharmaceutical formulation for use or method in the prophylaxis and therapy of viral infections or a complication or consequence thereof. In particular the invention relates to the use of synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate and their metabolic derivatives in the prophylaxis and therapy of viral infections, viral replication and the development and prevention of a deficiency of the immune system resulting in the development of opportunistic infections and certain cancers. More especially the invention relates to the use of synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate and their metabolic derivatives in the prophylaxis and therapy of viral infections.
Other embodiments provide a pharmaceutical formulation or method to treat a viral infection or to ameliorate one or more symptoms associated with a viral infection comprising administering to an infected patient an effective amount of a compound or a formulation as disclosed herein.
It is an object of the present invention to provide a composition, which includes at least one synthetic, non-hormonal 21 -aminosteroid, preferably tirilazad mesylate for treatment, therapeutic or prophylaxis, against a viral infection. The composition containing at least one synthetic, non-hormonal 21 -aminosteroid, preferably tirilazad mesylate is designed so that upon administration, it has maximum bioavailability.
Accordingly, the synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate disclosed herein provide a pharmaceutical formulation or a method for treating a viral infection; for use in treating any infection, preventing a future infection and/or minimizing the effects of a future infection by a viral infection; said method comprising administering to a patient in need thereof a prophylactically or therapeutically effective amount of a composition comprising at least one synthetic, non-hormonal 21 -aminosteroid, preferably tirilazad mesylate.
The present invention is directed towards providing an improved pharmaceutical formulation or method in the prophylaxis and therapy of retroviral infections or a complication
or consequence thereof. In particular the invention relates to the use of synthetic, non- hormonal 21 -aminosteroids in the prophylaxis and therapy of viral infections, viral replication and the development and prevention of a deficiency of the immune system resulting in the development of opportunistic infections and certain cancers. More especially the invention relates to the use of synthetic, non-hormonal 21 -aminosteroids in the prophylaxis and therapy of viral infections, an example of which is the retrovirus, thought to be responsible for the Acquired Immune Deficiency Syndrome (AIDS) and AIDS related syndromes, believed to result from infection from the Human Immunodeficiency Virus (HIV), antibodies to which are found in almost all individuals diagnosed with AIDS.
It is an object of the present invention to provide a composition, which includes at least one synthetic, non-hormonal 21 -aminosteroid for treatment, therapeutic or ' prophylaxis, against a viral infection. The composition containing at least one synthetic non- hormonal 21 -aminosteroid is designed so that upon administration, it has maximum bioavailability. This satisfies the need for a non-specific, antiviral treatment' with immune modulatory properties.
The embodiments of the present invention provide an effective antiviral agent with enhanced solubility and maximal bioavailability by specifically designing the delivery system. This is effected by specifically choosing the carrier system for the synthetic non- hormonal 21 -aminosteroids.
It is an object of the present invention to provide a composition that potentiates or intensifies the effectiveness of the immune system. This immune potentiating capability can be exploited to therapeutic advantage in numerous specific ways, in particular to treat infections, regardless of etiology, for example viral, bacterial, or fungal.
The present invention is further directed to a pharmaceutical formulation or method in the prophylaxis and therapy against AIDS related syndromes such as cachexia and/or wasting syndrome.
According to the present invention there is provided a pharmaceutical formulation or a method of treatment for treating a viral infection; for regulating the immune system; for use in normalizing the balance of Th1 /Th2 immune system; for use in treating any infection, preventing a future infection and/or minimizing or combatting the effects of a future
infection by a virus; for treating an immune disorder, said method comprising administering to a patient in need thereof a prophylactically or therapeutically effective amount of a composition comprising at least one synthetic, non-hormonal 21 -aminosteroid.
The advantage of this is that an effective anti-viral therapy is provided that has minimal risk of conferring resistance.
In another embodiment the synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate are delivered to infected cells by incorporating the synthetic, non- hormonal 21 -aminosteroids, preferably tirilazad mesylate into liposomes or carbohydrate vehicles. The liposomes or carbohydrate vehicles can be specifically targeted to infected viral cells by placing viral directed antibodies on the surface of these liposomes or vesicles.
In one embodiment of the invention the synthetic non-hormonal 21 - aminosteroid is selected from the group consisting of: tirilazad (( 1 6-alpha)-21 -[4-(2,6-di-1 - pyrrolidinyl-4-pyrimidinyl)-1 -piperazinyl]-1 6-methylpregna-1 ,4,9( 1 1 )-triene-3,20-dione); 5- alpha-tirilazad (21 -4-2,6-bis(1 -pyrrolidinyl)-4-pyrimidinyl-1 -piperazinyl-1 6-alpha-met hyl-5- alpha-pregna-1 ,9( 1 1 )-diene-3,20-dione and the 5-beta-isomer (5-beta-tirilazad) (21 -4-2,6- bis( 1 -pyrrolidinyl)-4-pyrimidinyl-1 -piperazinyl-1 6-aIpha-methyl-5-beta-pregna-1 ,9( 1 1 )-diene- 3,20-dione) ; 6-alpha-hydroxy -tirilazad (6-alpha-hydroxy-21 -4-2,6-bis(1 -pyrrolidinyI)-4- pyrimidinyl-1 -piperazinyl-1 6-alpha-methylpregna-1 ,4,9(1 1 )-triene-3,20-dione) and 6-beta- hydroxytirilazad (6-beta-hydroxy-21 -4-2,6-bis( 1 -pyrrolidinyl)-4-pyrimidinyl-i -piperaziny 1-1 6- alpha-methylpregna-1 ,4,9( 1 1 )-triene-3,20-dione and pharmaceutically acceptable salts thereof or their metabolites.
In another embodiment the synthetic non-hormonal 21 -aminosteroid is tirilazad, while in a preferred embodiment, tirilazad mesylate.
In a preferred embodiment of the invention conditions for administration are to give synthetic non-hormonal 21 -aminosteroids orally or parenterally, e.g. IV (that is by injection, infusion or continuous drip) or IM or rectally by suppository. Females may be given higher doses than males since, on the average, they may metabolize aminosteroids more rapidly than males.
In another embodiment it may be preferable to co-administer an inhibitor of 21 -
aminosteroid metabolism, such as ketoconazole, naragin or TAO (triacetyloleandomycin) prior to or concurrently with aminosteroid administration to raise the blood level of the 21 - aminosteroids and/or certain of its metabolites. Because females metabolize aminosteroids more rapidly than males, administration of an inhibitor of 21 -aminosteroid metabolism can raise blood levels in females to that of males.
In another embodiment a method of treatment is provided comprising administering a first composition comprising at least one 21 -aminosteroid-metabolism inhibitor, later followed by a second composition comprising at least one synthetic non- hormonal 21 -aminosteroid, during the treatment protocol.
In another embodiment the composition further includes a pharmaceutically ■ acceptable carrier, which in one embodiment is a cyclodextrin, alpha-cyclodextrin, beta- cyclodextrin, (beta-hydroxypropylcyclodextrin) gamma-cyclodextrin and In another embodiment is vitamin E oil.
In another embodiment the composition further includes a halogen salt. In another embodiment, the synthetic non-hormonal 21 -aminosteroids are halogenated.
In accordance with the present invention, production and/or activity of neutrophils and/or monocytes is enhanced in patients to whom A) a halogenated salt of a 21 - aminosteroid and/or B) a halogen salt plus the synthetic non-hormonal 21 -aminosteroid is administered. Much better results are obtained when there is an adequate supply of myeloperoxidase in the patient being treated. Myeloperoxidase is present within neutrophils in the form of crystallised granules myeloperoxidase, unless the neutrophils have become "degranulated ". Degranulated neutrophils contain a reduced amount of granules of myeloperoxidase, or contain no granules of myeloperoxidase, as a result of several mechanisms, many of which relate to conditions against which the present invention is directed. Patients having low counts of neutrophils, and/or having a large portion of their neutrophil count degranulated will have low myeloperoxidase index (MPXI). Such patients are immunosuppressed and have limited capability to remove opportunistic infections caused by pathogenic organisms such as viruses, bacteria, protozoa's or fungi. Additionally, neutrophils have a lifetime of about 2 or 3 days, so it preferred that their supply be replenished on a regular basis to achieve the full benefits of the aspects of the present invention, which require myeloperoxidase present in the patient. According to the present
invention, a supply of myeloperoxidase is provided by stimulating production of fresh neutrophils, which will contain granules of myeloperoxidase and other anti-microbial enzymes.
The importance of myeloperoxidase according to one aspect of the present invention is that it can react with hydrogen peroxide (H202) and halogen to generate hypohalogenous acid, e.g . , hypobromous acid (HOBr) . The selected halogen can be selected from the group consisting of chlorine, bromine, fluorine and iodine.
. Halogenated salts or halogenated 21 -aminosteroids can provide the halogen needed in the reaction described in the preceding paragraph. Hypohalogenous acid is a potent sterilant, which is effective for eradicating the deleterious agent or agents in the circulatory system, thereby providing benefits to the patient, e.g. , reducing viral quantitative culture measurement in plasma and serum.
Furthermore, it has been found that hypohalogenous acid is very toxic, such that it could not be administered to a patient in amounts sufficient to provide the desired effects without being unduly toxic. The reason for this is that the hypohalogenous acid has a very short half-life. The advantage of administering a pharmaceutical formulation containing a halogenated salt of at least one synthetic non-hormonal 21 -aminosteroid or a halogen salt plus at least one the synthetic non-hormonal 21 -aminosteroid with a suitable carrier is three fold:
1 . The 21 -aminosteroid eliminates the virus by a specific anti-viral mechanism, together with producing immunomodulation.
2. The halogen is released locally, where it combines with hydrogen peroxide to produce the sterilant hypohalogenous acid, which reduces viral levels by an alternative mechanism. Because of the local interaction that occurs at very low concentrations, the hypohalogenous acid does not have toxic effect.
3. The 21 -aminosteroid has immuno upregulatory properties, for example NK, and/or dendritic.
The compounds of the invention can be formulated and administered as free bases or in the form of their pharmaceutically acceptable salts for purposes of stability, convenience of crystallisation, increased solubility, and the like.
One useful property of the synthetic, non-hormonal 21 -aminosteroids,
preferably tirilazad mesylate and their metabolites is their anti-viral activity, which is manifested, pursuant to one aspect of the present invention, in a broad-spectrum anti-viral activity. Accordingly, the present invention contemplates administering daily to a subject an amount of at least one synthetic, non-hormonal 21 -aminosteroids, preferably tirilazad mesylate that is clinically effective in treating or preventing a viral infection, which the subject suffers or is at risk from infection. Illustrative viruses against which the invention can be applied are the virus of the genus hepatitis, including that caused by the known hepatitis viruses, i.e. , hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV) and delta hepatitis virus (HDV), as well as the hepatitis induced by cytomegalovirus (CMV) or Epstein- Barr virus (EBV), pestiviruses (also known as mucosal disease viruses, such as bovine virus diarrhea virus BVDV, hog cholera virus, and sheep border disease), among other viruses.
In one embodiment of the invention the viral infection is a retrovirus, in another embodiment, the retroviral infection is HIV or AIDS virus, Herpes virus, cytomegalovirus, or an animal virus, and in an additional embodiment the viral infection is a iipid envelope virus.
In another embodiment, the pharmaceutical formulation is used to treat AIDS related syndromes, including cachexia and/or wasting syndrome.
Additionally, the present invention is also broadly directed at the use of the pharmaceutical formulation in the treatment (i.e. , in the sense of treating an existing infection, preventing a future infection, minimizing the effect of a future infection and/or enhancing the performance of a vaccine) of all infections which are not retroviral infections and can also cause dysregulation of the immune system, treatment resulting in the regulation of the immune system , several representative examples of which include one or more kind of Mycoplasma, and/or one or more diseases caused by Mycoplasmas and/or one or more of the following infections: hairy leukoplakia, oral candidosis, mouth ulcerations aphthous/herpatic/bacterial, fungal Candida, squamous oral carcinoma, Kaposi's sarcoma oral lesions, periodontitis, necrotizing gingivitis, human papilloma virus, rhinovirus and arboviral molluscum contagiosum, orafacial herpes zoster, Epstein barr virus, rotaviruses, togaviruses, including alpha viruses (also known as arboviruses, group A), filoviruses such as marburg and ebola viruses, flaviviruses (also known as arboviruses, group B, such as yellow fever, as well as hepatitis C and hepatitis G), rubiviruses (also known as rubella viruses e.g., human rubella virus), pestiviruses (also known as mucosal disease viruses, such as bovine virus diarrhorea virus BVDV, hog cholera virus, and sheep border disease), as well as any other non-retroviral
viral induced infections. Thus virus infections that may be treated include but are not limited to HIV, SIV, FIV, FELV, SHIV, Kaposi's Sarcom-associated herpes virus and other herpes viruses (e. g . HSV-1 , HSV-2, human herpes virus 6 (HHV-6) and HHV-8), the viruses associated with hepatitis (HAV, HBV, hepatitis C virus [HCV]), and human cytomegalovirus, togaviruses and flaviviruses, e.g., California encephalitis virus, St. Louis encephalitis virus, western equine encephalitis virus, eastern equine encephalitis virus, Colorado tick fever virus, LaCrosse encephalitis virus, Japanese encephalitis virus, yellow fever virus, Venezuelan equine encephalitis virus, Murray valley fever virus, tick-borne encephalitis virus, GB virus A, GB virus B, GB virus C, Dengue virus 1 , Dengue virus 2, Dengue virus 3, Dengue virus 4, Semliki Forest virus, Sinbis virus, Filoviruses, e.g. Marburg or Ebola virus, picornaviruses, rhinoviruses, coronaviruses, respiratory syncytial viruses, polioviruses, parainfluenza viruses and influenza viruses ( including type A, type B, and type C. The pharmaceutical formulation is also useful to ameliorate one or more symptoms associated with viral infections, e.g ., fever, pain or fatigue.
Pursuant to a preferred embodiment of the invention, an effective amount of synthetic, non-hormonal 21 -aminosteroid, as defined herein, is thus administered such as to produce a circulating concentration of the synthetic, non-hormonal 21 -aminosteroid and/or their metabolites sufficient to reduce viral loads as monitored by, e.g., viral titer methods or by PCR.
Treatment according to the present invention can be effected when the subject is a neonate. Administration is carried out prior to delivery of the neonate and/or during delivery of the neonate.
The synthetic, non-hormonal 21 -aminosteroids according to the present invention can be administered to a patient in any of a wide range of routes. Thus, with regard to the types of formulations in which the active compounds according to the present invention can be administered, as well as any additives can be included with the active compounds in the formulations, and the possible routes of administration, it is well known to those of skill in the art that such formulations can be provided in a wide variety of types, and it is within the skill of the ordinary artisans to select a specific formulation and route of administration and then test suitability for use. By way of example but not limitation, suitable routes include enteric, parenterai, topical, oral, rectal, nasal or vaginal routes. Parenteral routes include subcutaneous, intramuscular, intravenous, intraperitoneal, intradermal and sublingual administration. Also,
compositions may be implanted into a patient or injected using a drug delivery system.
The pharmaceutical formulation according to the present invention may be administered locally or systemically. By systemic administration is meant any mode or route of administration that results in effective amounts of active ingredient appearing in the blood or at a site remote from the route of administration of the active ingredient.
Further, the pharmaceutical formulation according to the present invention may be administered intermittently. The advantage of this is that it allows the patient to suspend therapy for periods, without the worry of inactivity of the drug resulting from the development of a resistant strain.
The pharmaceutical formulation according to the invention may be formulated for enteral, parenteral or topical administration. Indeed all three types of formulations may be used simultaneously to achieve systemic administration of the active ingredient. '
In one embodiment of the invention, the synthetic, non-hormonal 21 -aminosteroid is micronized. In accordance with the present invention, the expression "micronized" means that the compound has been micronized in accordance with any process for micronizing, a number of which are known in the art. The micronized particles preferably include a percentage of particles, which are of a diameter, which is about 10 microns, or less, preferably, 5 microns or less, For example, in a preferred aspect of the invention, at least 80% of the particles in a formulation of micronized particles have a diameter of less than 5 microns. An alternative to micronizing a compound is to solubilize the compound and put it into liposomes of appropriate size. The manufacture of liposomes and the insertion of active ingredients into such liposomes are well known in the art.
For oral administration, the synthetic, non-hormonal 21 -aminosteroids can be formulated into solid or liquid preparations. Suitable formulations for oral administration include hard or soft gelatin capsules, dragees, pills, tablets, including soft-coated tablets, troches, lozenges, melts, powders, micronized particles, non-micronized particles, solutions, emulsions,
' elixrs, suspensions, syrups or inhalations and controlled release forms thereof.
One of the preferred formulations of the present invention is that the compound is enterically coated and is administered orally. In another embodiment, the compound is
administered sub-lingually.
In one embodiment of the invention the enteric coating is made of a polymer, preferably selected from the group consisting of polydactic-glycolic acid) polyester, cellulose acetate phthalate, hydroxypropyl-methyl cellulose phthalate poly(butyl methacrylate), (2-dimethyl aminoethyl) methacrylate, and methyl methacrylate.
Solid dosage forms in addition to those formulated for oral administration include rectal suppositories.
According to a further aspect of the invention the compound is formulated in a liposome.
In another embodiment of the invention, liposomes are provided carrying the synthetic, non-hormonal 21 -aminosteroids targeted to virus-infected cells by putting antibodies to the viral antigens on their surfaces. The advantage of this is that the liposome can selectively target virus-infected cells.
In another embodiment of the present invention, liposomes are provided carrying high concentrations of at least one synthetic, non-hormonal 21 -aminosteroid to infected cells.
Suitable injectable solutions include intravenous, subcutaneous and intramuscular injectable solutions. Examples of injectable forms include solutions, suspensions and emulsions. Typically the compound(s) is injected in association with a pharmaceutical carrier such as normal saline, Ringers solution, dextrose solution and other aqueous carriers known in the art. Appropriate non-aqueous carriers may also be used and examples include cyclodextrin, preferably hydroxypropyl beta cyclodextrin, mixed oils (vitamin E oil), polyethylene glycol and ethyl oleate. A preferred carrier is cyclodextrin in water.
Frequently, it is desirable to include additives in the carrier such as buffers and preservatives or other substances to enhance isotonicity and chemical stability.
The synthetic, non-hormonal 21 -aminosteroids can also be administered topically. Suitable formulations for topical administration include creams, gels, jellies, mucliages, pastes and ointments. The compounds may be formulated for transdermal administration, for example in the form of transdermal patches so as to achieve systemic
administration.
The synthetic, non-hormonal 21 -aminosteroids may also be administered in the form of an implant.
The synthetic, non-hormonal 21 -aminosteroids may also be administered in the form of an infusion solution or as a nasal inhalation or spray.
In another embodiment it may also be preferable to co-administer with at least one additional conventional anti-viral agent. Examples of anti-virals include, but are not limited to nucleoside analogues (AZT; ddC; ddl; d4T; 3TC; BW 1 592; PMEA/bis-POM PMEA; dOTC; DAPD); non-nucleoside reverse transcriptase inhibitors (delavirdine; DMP 266; HBY097; loviride; nevirapine, emivirine; AG 1 549; PNU 142721 ; Calanolide A; DPC961 ); protease inhibitors (ABT- 378; ritonavir; nelfinavir; BW 141 ; KNI-272; indinavir; saquinavir; L-756,423; DMP-450; BMS- 232630); ALX40-4C; hydroxyurea; lobucavir; pentafuside; T-1 249; PRO 542; FP-21 399; AMD 31 00; HE-2000 and peptide T.
Further examples of anti-virals include, but are not limited to Abacavir; Acemannan; Acyclovir; Acyclovir Sodium; Adefovir; Alovudine; Alvircept Sudotox; Amantadine Hydrochloride; Aranotin; Arildone; Atevirdine Mesylate; Avridine; Cidofovir; Cipamfylline; Coviracil; Cytarabine Hydrochloride; Delavirdine Mesylate; Desciclovir; Didanosine; Disoxaril; Edoxudine; Emivirine; Emtricitabine; Enviradene; Enviroxime; Epivir; Famciclovir; Famotine Hydrochloride; Fiacitabine; Fialuridine; Fosarilate; Foscamet Sodium; Fosfonet Sodium; Ganciclovir; Ganciclovir Sodium; Idoxuridine; Indinavir; Kethoxal; ' Lamivudine; Lobucavir; Lodenosine; Lopinavir, Memotine Hydrochloride; Methisazone; Nelfinavir; Nevirapine; Penciclovir; Pirodavir; Ribavirin; Rimantadine Hydrochloride; Saquinavir Mesylate; Ritonavir; Somantadine Hydrochloride; Sorivudine; Statolon; Stavudine; Tenofovir; Tilorone Hydrochloride; Trifluridine; Valacyclovir Hydrochloride; Vidarabine; Vidarabine Phosphate; Vidarabine Sodium Phosphate; Tipranavir, Viroxime; Zalcitabine; Zidovudine; Zinviroxime and Interferons ( ,β,γ).
The components of any of the pharmaceutical formulations disclosed herein can be administered simultaneously (in a combination formulation), essentially simultaneously (e.g., administration of each compound a few minutes or a few hours apart), or can be administered sequentially, e.g. , several days apart, or more than a week apart. For example, a compound of the present invention, and at least one synthetic, non-hormonal 21 -aminosteroid (and/or an anti-
viral agent) can be administered together, or essentially simultaneously, e.g. , administration of each compound a few minutes or a few hours apart, or can be administered sequentially, e.g . , several days apart, or more than a week apart. All such variations in administration of the combination therapy are encompassed within the scope of the invention.
In another embodiment, the composition is incorporated in a pharmaceutically acceptable carrier, diluents, vehicles and the like for systemic administration by feeding. An example of such a carrier is cyclodextrin, (alpha-cyclodextrin, beta-cyclodextrin (preferably beta-hydroxypropylcyclodextrin) and gamma-cyclodextrin.
With regard to dosage and duration of treatment according to any aspect of the present invention, it is recognized that the ability of an artisan skilled in pharmaceutical • administration of drugs to determine suitable dosages depending on many inter-related factors is well known, and skilled artisans are readily able to monitor patients to determine whether treatment should be started, continued, discontinued or resumed at any given time. For example, dosages of the compounds are suitably determined depending on the individual cases taking symptoms, age and sex of the subject and the like into consideration. The amount of the compound to be incorporated into the pharmaceutical composition of the invention varies with dosage route, solubility of the compound, administration route, administration scheme and the like. An effective amount for a particular patient may vary depending on factors such as the condition being treated, the overall health of the patient and the method, route and dose of administration. The clinician using parameters known in the art makes determination of the appropriate dose. Generally, the dose begins with an amount somewhat less than the optimum' dose and it is increased by small increments thereafter until the desired or optimum effect is achieved. Suitable dosages can be determined by further taking into account relevant disclosure in the known art.
In general, the amount of compound delivered to the patient is sufficient to achieve a plasma concentration of from about 3 to 10 μg/ml to about 5000 μg/ml of plasma, typically about 3 to about 50 μg/ml or about 5 to about 25 μg/ml. However, when liposomes targeted to viral infected cells are used to administer the synthetic, non-hormonal 21 - aminosteroids, high doses of 25 mg/ml are used. The effective amount is optionally administered in a dosage ranging between 10 μg/kg and about 20,000 μg/kg of body weight of the patient. Unit dosages for any of the conditions described in the disclosure will typically comprise about 1 -1 000 mg/day of a synthetic, non-hormonal 21 -aminosteroid often about
5 to 500 mg/day, ideally 400 mg/day with an optimal blood plasma concentration of 60 μM in the blood all day. Preferable doses are 1 .5 mg/kg , every 6 hours with i.v. infusion over 1 0- 30 mins for 8 to 1 0 days. Preferable pediatric doses range from 0.001 to 1 00 mg/kg/day, with optimal doses in the range of 1 .5 mg/kg/day.
Administration of the synthetic, non-hormonal 21 -aminosteroids has a direct anti- viral effect, as reported herein.
Further, the invention provides use of the composition in the manufacture of a medicament for use in the prophylaxis or therapy of a viral infection or a complication or consequence thereof.
The components of any of the combination therapies disclosed herein can be administered simultaneously (in a combination formulation), essentially simultaneously (e.g. administration of each compound a few minutes or a few hours apart) or can be administered sequentially (e. g . several days apart or more than one week apart) . All such variations in administration of the combination therapy are encompassed within the scope of the invention.
Further, the invention provides use of the composition in veterinary medicine, prophylactically and therapeutically in animal populations that are subject to a viral infection that also compromises immune response and cause infection.
In another embodiment, the subject is a mammal.
In one embodiment, the viral infection is a hepatitis viral infection selected from a HAV, HBV, HCV, HDV, EBV, CMV, BVDV, hog cholera virus, and sheep border disease virus infection.
Further, the invention provides use of the composition in the manufacture of a medicament for use in the prophylaxis or therapy of a viral infection or a complication or consequence thereof.
Additionally, the invention provides use of the composition to provide protection against virus infections in immunocompromised animals and humans. These compositions may be used prophylactically or therapeutically to protect animals or patients from the
consequences of infection by pathogenic viruses.
Further, the invention provides use of the composition in veterinary medicine, prophylactically and therapeutically in animal populations that are subject to viral infection that compromises immune response and cause infection.
Additionally, the invention provides use of the composition in the treatment of immunocompromised AIDS patients or those infected with a retrovirus such as HIV virus showing the AI DS related complex (ARC) .
The present invention further provides a method of treatment or a pharmaceutical composition to regulate the immune system, treat an immune disorder, normalize the balance of Th1 /Th2 immune system, prophylactically or therapeutically treat a viral infection, preventing a future infection, protecting those at risk of encountering the virus and/or minimizing the effect of a future infection, the method comprising administering to a patient in need thereof a prophylactically or therapeutically effective amount of a composition comprising at least one 21 -aminosteroid-metabolism inhibitor and at least one synthetic non-hormonal 21 -aminosteroid .
Cancer is an example of diagnosis where treatment often results in the production of an immune disorder, and it would be appropriate to administer one of the pharmaceutical formulations described in the present invention.
Additionally, the present invention further provides a method of treatment or a pharmaceutical formulation, for use in a treatment protocol to regulate the immune system, treat an immune disorder, normalize the balance of Th1 /Th2 immune system, prophylactically or therapeutically treat a viral infection, preventing a future infection, protecting those at risk of encountering the virus and/or minimizing the effect of a future infection, the method comprising administering to a patient in need thereof a prophylactically or therapeutically effective amount of a first composition comprising at least one 21 -aminosteroid metabolism inhibitor, later followed by a second composition comprising at least one 21 -aminosteroid, during the treatment protocol.
Further, the invention provides a pharmaceutical formulation for regulating a dysregulated immune system comprising administering to a patient in need thereof a
prophylactically or therapeutically effective amount of a composition comprising at least one synthetic non-hormonal 21 -aminosteroid.
EXAMPLES
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, practice the present invention to its fullest extent. The following detailed examples describe how to test the various compounds of this invention and/or perform the various processes of the invention and are to be construed as merely illustrative, and not limitations of the preceding disclosure in any way whatsoever. Those skilled in the art will promptly recognize appropriate variations from the procedures.
These and other features and advantages of the present invention will be more clearly understood with reference to the following description of some embodiments thereof and with reference to the following tables and the accompanying drawings in' which: -
Fig. 1 Demonstrates the anti-viral effect compared to the cytotoxicity of a batch of tirilazad mesylate Fig. 2 Demonstrates the anti-viral effect compared to the cytotoxicity of another batch of tirilazad mesylate Fig. 3 Demonstrates the anti-viral effect compared to the cytotoxicity of an additional batch of tirilazad mesylate Fig. 4 Demonstrates the anti-viral effect compared to the cytotoxicity of a batch of ribavirin Fig. 5 Demonstrates the anti-viral effect compared to the cytotoxicity of another batch of ribavirin
Example 1
Protocol for the Evaluation of Compounds against Bovine Viral Diarrhea Virus in vitro.
A plaque inhibition assay procedure was employed to evaluate compounds for antiviral activity against bovine viral diarrhea virus (BVDV) , strain D/8 in Madin-Darby bovine kidney (MDBK) cells. The cells were pregrown in 1 2-well tissue culture plates using Eagle's
Minimum Essential Medium (EMEM supplemented with 1 0 % heat inactivated fetal bovine serum (FBS), L-glutamine and gentamicin. Antiviral assays were designed to test six concentrations of each compound in triplicate against the challenge virus. The virus was diluted in EMEM without serum and an inoculum of 0.5 ml per well was adsorbed for 4 hours. Cell control cultures were sham inoculated with 0.5 ml EMEM without serum. After virus adsorption, the inoculum was removed and 1 .0 ml of the appropriate drug dilution in EMEM + 1 0 % heat inactivated FBS + 0. 1 % DMSO was added. Cell and virus controls were refed with medium alone. The plates were incubated at 37°C in a humified atmosphere containing 5 % C02 until plaques were formed (Day 3) . The cultures were fixed with 10 % formalin and stained with methylene blue. Plaques were counted with the aid of a dissection microscope. Plaque reduction was determined by comparing the mean plaque count of drug treated cultures with the mean plaque number in the untreated virus infected control cultures and expressed in percent.
NOTE: BVDV is used as a surrogate virus for human Hepatitis C virus.
The results in Example 1 summarised in Table 1 and figures 1 to 5 demonstrate that the therapeutic index of tirilazad mesylate is superior to ribavirin in the BVDV model of Hepatitis C virus.
Table 1 Summary of a comparison between ribavirin and tirilazad mesylate on anti-viral effect (MDBK/BVDV EC50 μg/ml) , cytotoxicity (MDBK TC50 μg/ml) and therapeutic Index)
Figures 1 to 5 are based on the data contained in the following Tables 2 to 6 respectively.
TABLE 2
IN VITRO ANTIVIRAL RESULTS
XTT ASSAY
TIRILAZAD MESYLATE DRUG AVS TIRILAZAD MESYLATE
10
B C
D E F G
fox-cell toxϊcity control VC-virus contra BOLD-highest drug cons values shown are optical densities
VIRUS BVDV
CELLS MDBK
REAGENT 0,176
VIRUS CONTROL 0,152
CELL CONTROL 1,078
TIRILAZAD MESYLATE ANTIVIRAL TEST VALUES CYTOTOXICITY TEST VALUES
ROW ON CONC. • MEAN % RED. IN MEAN % CELL COLORIMETRIC
PLATE /G/Ynll O.D. VIRAL CPE O.D. VIABILITY CONTROL
BASED ON low B 0,00032 0,007 1% 1,099 100% 0,022
VALUES OF C 0,001 -,025 0% 1,093 100% 0,009
COLUMNS 7 D 0,0032 -,085 0% 1,336 100% 0,008 through 12 E 0,01 • -,045 0% 1,357 100% 0,009
(RIGHT SIDE F 0,032 -,076 0% 1,135 100% 0,011
OF PLATE) G 0,1 -,022 0% 1,134 100% 0,011
BASED ON B 0,32 0,067 7% 1,241 100% 0,019
VALUES OF C 1 0,091 10% 1,306 100% 0,013
COLUMNS 1 D 3,2 0,004 0% 1,386 100% 0,016 through 6 E 10 0,966 100% 1,092 100% 0,015
(LEFT SIDE F 32 0,326 35% 0,407 38% 0,025
OF PLATE high G 100 0,063 7% 0,175 16% 0,039
TABLE 3
IN VITRO ANTIVIRAL RESULTS
XTT ASSAY
TIRILAZAD MESYLATEDRUG AVS TIRILAZAD MESYLATE
B C D E F G
tox-cell toxlclty CC-cell toxicity VC-virus control BOLD-highest drug cons values shown are optical densities
VIRUS BVDV CELLS MDBK
REAGENT 0,221 VIRUS Toxicity 0,275 CELL CONTROL 1,396 DIFFERENTIAL 1,121
TIRILAZAD MESYLATE ANTIVIRAL TEST VALUES CYTOTOXICITY TEST VALUES
ROW ON CONC. MEAN % RED. IN MEAN % CELL COLORIMETRIC
PLATE (μ G/ml) O.D. VIRAL CPE O.D. VIABILITY CONTROL low B 0,32 -,135 0% 1,398 100% 0,010
C 1 -,161 0% 1,343 96% 0,003
D 3,2 -,113 0% 1,392 100% 0,009
E 10 0,753 67% 1,099 79% 0,002
F 32 0,837 75% 1,013 73% 0,000 high G 100 0,486 43% 0,601 43% 0,000
TABLE 4
IN VITRO ANTIVIRAL RESULTS
XTT ASSAY
TIRILAZAD MESYLATE DRUG AVS TIRILAZAD MESYLATE
1 2 3 4 5 6 7 8 9 10 11 12 reagent background plastic backgrounc i
0,221 0,213 0,219 0,223 0,221 0,227 0,024 0,023 0,024 0,025 0,023 0,023 cc/vc drug TRD12 OLD BATCH expenm tox cc/vc
B 1,891 1,795 0,503 0,382 0,383 1,813 1,536 C 1,764 1,502 0,454 0,497 0,350 1,576 1,497
D 1,809 1,707 0,538 0,595 0,671 1,537 1,662 E 1,578 0,345 1,356 1,289 1,265 1,339 0,668 F 0,347 0,548 1,293 1,249 1,328 1,296 0,518 G 0,600 0,380 0,721 0,683 0,707 0,631 0,517 c Dlorimetric background
0213 0,216 0,228 0,226 0,226 0,230 tox cell toxicity CC cell control VC virus control BOLD highest drug con values shown are optical densities
VIRUS BVDV
CELLS MDBK
REAGENT 0,221
VIRUS CONTROL 0,275
CELL CONTROL 1,396
TIRILAZAD MESYLATE ANTIVIRAL TEST VALUES CYTOTOXICITY TEST VALUES
ROW ON CONC. MEAN % RED. IN MEAN % CELL COLORIMETRIC
PLATE /G/rnl] O.D. VIRAL CPE 0 D. VIABILITY CONTROL low B 0,32 -,082 0% 1,622 100% 0,009
C 1 -,067 0% 1,444 100% 0,005
D 3,2 0,100 9% 1,447 100% 0,006
E 10 0,800 71% 1,231 88% 0,007
F 32 0,799 71% 1,106 79% -,005 high G 100 0,216 19% 0,403 29% -,008
TABLE 5
IN VITRO ANTIVIRAL RESULTS
XTT ASSAY
DRUG RIBAVIRIN DRUG: AVS RIBAVIRIN
1 2 3 4 5 6 7 8 9 10 11 12 reagent background plastic background
0,222 0,223 0,222 0,224 0,220 0,227 0,023 0,024 0,023 0,024 0,024 0,024 tox cc/vc drug TRD12 OLD BATCH expenm tox cc/vc
B 1,729 1,762 0,523 0,503 0,360 1,581 1 ,842 C 1,574 1,396 0,396 0,355 0,389 1,415 1,469 D 1,788 1,672 0,497 0,390 0,636 1,518 1,651 E 1,715 0,363 0,824 0,800 0,759 1,550 0,379 F 0,999 0,393 1,084 1,060 1,093 0,998 0,366 G 0,530 0,353 0,599 0,562 0,578 0,567 0,393 c olorimetric background
0.235 0,223 0,229 0,235 0,228 0,231 tox cell toxicity CC cell control VC virus control BOLD highest drug cons values shown ar*e optical densities
VIRUS BVDV CELLS MDBK
REAGENT 0,223
VIRUS CONTROL 0,152
CELL CONTROL 1,409
DRUG RIBAVIRIN ANTIVIRAL TEST VALUES CYTOTOXICITY TEST VALUES
ROW ON CONC. MEAN % RED. IN MEAN % CELL COLORIMETRIC
PLATE (UG/ml) O.D VIRAL CPE O.D VIABILITY CONTROL low B 0,0781 0,080 6% 1,424 100% 0,008
C 0,25 0,001 0% 1,267 90% 0,005
D 0,781 0,121 10% 1,418 100% 0,012
E 2,5 0,414 33% 1,404 100% 0,006
F 7,81 0,705 56% 0,776 55% 0,000 high G 25 0,193 15% 0,314 22% 0,012
TABLE 6
IN VITRO ANTIVIRAL RESULTS
XTT ASSAY
DRUG RIBAVIRIN DRUG AVS RIBAVIRIN
C D E F G
tox-cell toxicity CC-cell control VC-virus control BOLD-highest drug cons values shown are optical densities
VIRUS BVDV
CELLS MDBK
REAGENT 0,244
VIRUS CONTROL 0,047
CELL CONTROL 1,129
DRUG RIBAVIRIN ANTIVIRAL TEST VALUES CYTOTOXICITY TEST VALUES
ROW ON CONC. MEAN % RED. IN MEAN % CELL COLORIMETRIC
PLATE liuG/ml) O.D. VIRAL CPE O.D. VIABILITY CONTROL low B 0,0781 0,052 5% 1,204 100% -,046
C 0,25 0,081 7% 1,202 100% -,056
D 0,78 0,117 11% 1,318 100% -,054
E 2,5 0,764 71% 1,202 100% -,052
F 7,81 0,504 47% 0,467 41% -,056 high G 25 0,108 10% 0,134 12% -,053
Examples 2 to 8 describe methods of how the tirilazad mesylate can be formulated , so that upon administration, by several routes of administration, there is maximum bioavailability.
Example 2
This example describes how synthetic, non-hormonal 21 -aminosteroid can be prepared with cyclodextrin according to the present invention.
Preparation of tirilazad mesylate or tirilazad in hydroxypropyfbeta-cyc/odextrin (HP-beta-CD) solution
' 1 . Forty five grams of HP-beta-CD is weighed out on an analytical balance, and placed into a clean beaker.
2. To this one litre of sterile physiological saline is added.
3. The resultant mixture is covered and mixed on a stirrer for four hours or overnight, until a clear solution is obtained .
4. Non-micronised tirilazad mesylate or tirilazad is added to this, at a concentration of 20 mg/ml, and is stirred again, until the solution is clear.
5. This is then passed through a 0.2 micron filter to sterilise it, and is then aliquoted into sterile containers.
This formulation is preferably orally administered and is a preferred embodiment.
Example 3
The example describes one method of encapsulating tirilazad mesylate by enterically coating with a cellulose acetate phthalate film. The use of enteric coating targets the release of the composition in the lower gastrointestinal tract. The manufacture of enterically coated capsules, cachets, powders, tablets etc, is well known in the art. The following is provided by way of example:
Cellulose acetate phthalate films
The composition can include at least one synthetic non-hormonal 21 - aminosteroid, i.e. tirilazad mesylate.
Example 4
An alternative method to formulate the compositions is put the synthetic non- hormonal 21 -aminosteroids into liposomes of appropriate size. The manufacture of liposomes and the insertion of active ingredients into such liposomes is well known in the art. The following is provided by way of example.
Preparation of Tirilazad Mesylate in liposomes
400 mg phosphatidyl choline, 1 00 mg cholesterol and 80 mg of tirilazad mesylate is dissolved in a solution of chloroform:methanol (2: 1 , v/v) .
They mixture is then dried by rotary evaporation onto the sides of a round bottomed flask.
3. The resultant film is rehydrated by adding 8 mis of 0.9 % w/v sodium chloride solution. 4. The size of the resultant liposomes are measured by photon correlation spectroscopy using a Malvern Zetasizer 3000.
If required, liposomes can be produced below 400 nm by the use of sonication.
Formulations that comprise liposomes can be delivered to a subject by any standard route, e.g. , oral, aerosol or parenteral (e.g., i.v. or i.m.) .
Example 5
By formulating tirilazad mesylate in a suppository formulation, it can be administered rectally. Formulations for rectal administration may be presented as a suppository with a suitable base comprising for example cocoa butter or a salicyclate. The following is included by way of example:
Preparation of Tirilazad Mesylate in Suppository form
1 . Tirilazad mesylate is weighed out accurately, the amount dependant on how many suppositories will be produced. There will be 250 mg per suppository.
2. Tirilazad mesylate is blended with the suppository base, forming an homogenous mixture of the two.
3. The mixture is poured into individual plastic casings, which are sterilely 'sealed, and left to harden. '
The suppository base can be a series of triglycerides derived from edible vegetable oils, which may resemble cocoa butter in their properties. They are extremely stable, uniform in condition, which results in precise melting characteristics and need no special storage conditions. Typical properties may be:
FFA %: 0. 1
Saponificatibn value: 242
Iodine value: 3
Moisture %: 0. 1 Melting Point, closed capillary 35°C
Example 6
Preparation of Tirilazad mesylate for IV administration by attaching to Polyethylene glycol
Another method of administering the synthetic, non-hormonal 21 -aministeroids, is to administer them parenterally. One method of achieving this is by attaching them to a carrier molecule, for example a biocompatible polymer. One of the best biocompatible polymers is polyethylene glycol (PEG) due to its many useful properties including: lack of
toxicity and immunogenicity, nonbiodegradability and ease of excretion from living organisms, increased circulating half-life in blood, potentially increasing bioavailability and potency.
The term PEG means an ethylene glycol polymer that contains about 20 to about 2000000 linked monomers, typically about 50 - 1 000 linked monomers, usually about 1 00 - 300. Polyethylene glycols include PEGs containing various numbers of linked monomers e.g. PEG20, PEG30, PEG40, PEG60, PEG80, PEG 1 00, PEG 1 1 5, PEG200, PEG300, PEG400, PEG500, PEG600, PEG 1 000, PEG 1 500, PEG2000, PEG3350, PEG4000, PEG4600, PEG5000, PEG6000, PEG8000, PEG 1 1 000, PEG 1 2000, PEG2000000 and any mixtures thereof .
Alternatively, the compounds can be mixed with an excipient. The term excipient means a component or an ingredient that is acceptable in the sense of being compatible with the other ingredients of invention compositions or formulations and not overly deleterious to the patient or animal to which the formulation is to be administered. As used herein, excipients are usually liquids, including benzyl benzoate, cottonseed oil, N,IM- dimethylacetamide, an alcohol such as a C2.12 alcohol (e.g. ethanol), glycerol, peanut oil, PEG, vitamin E, poppyseed oil, propylene glycol, safflower oil, sesame oil, soybean oil and vegetable oil. Excipients as used herein will usually exclude chloroform, dioxane and DMSO. Excipients comprise one or more components typically used in the pharmaceutical formulation arts, e.g. fillers, binders, disintegrants and lubricants.
Inventions compositions suitable for parenteral delivery of synthetic non- hormonal 21 -aminosteroids to humans or animals typically comprise two or three or more excipients. Exemplary embodiments include ( 1 ) any two, three or four of propylene glycol, PEG200, PEG300, ethanol and benzyl benzoate and (2) any two, three or four of propylene glycol, PEG100, PEG200, PEG300, PEG400 and benzyl benzoate.
Example 7
Additional preparation of Tirilazad mesylate for IV administration
Each 1 ml of solution contains 1 .5 mg tirilazad mesylate. 1 00 ml solution contains 1 50 mg tirilazad mesylate. The dosage form is, but not limited to, 1 .5 mg/kg every 6 hours with I.V. infusion of tirilazad mesylate over 1 0 to 30 mins for 8 to 1 0 days..
Tirilazad mesylate is administered by peripheral or central intravenous infusion. In order to minimise vein irritation, the tirilazad mesylate is diluted before administration. For peripheral administration, the tirilazad mesylate is diluted one part tirilazad mesylate to 3 parts diluent, depending on fluid restriction requirements. For central vein administration, dilution of tirilazad mesylate with an equal volume of diluent is preferred, however no dilution is required for this route of administration. Lactated Ringers solution should not be used as a diluent due to the potential for precipitation of the admixture. Mixing of tirilazad mesylate with other intravenous medicines or fluids should be avoided .
The following diluents can be used , in which tirilazad mesylate is stable for 48 hours at room temperature:
0.45 % and 0.9 % sodium chloride 0.25 % and 0.5 % dextrose water.
If water is used for injection, a very hypotonic solution is produced. Because of possible microbiological contamination during dilution, the usual recommendation is to use the admixture within 24 hours if refrigerated or within 6 hours if kept at room temperature ( 1 5 to 30°C).
Diluted tirilazad mesylate is compatible with glass vials, polyvinyl chloride (PVC) plastic bags, ethyl vinyl acetate (EVA) bags, or polyefin bags.
Dedicated administration lines are preferred for tirilazad mesylate solutions. If a non-dedicated line must be used it should be flushed out with sodium chloride or dextrose before and after administering tirilazad mesylate.
Example 8
Additional formulation of tirilazad mesylate
' 1 . To a glass vessel add 400 mg of tirilazad mesylate and 2.5 ml of polyethylene glycol
300 and vortex for 1 minute to form a smooth, creamy liquid.
2. Add 2.5 ml of propylene glycol and vortex for 1 minute to form a uniform suspension.
3. Add 0.5 ml of benzyl benzoate and vortex for 1 minute to form a semi-clear liquid.
4. Add 1 .25 ml of absolute ethanol (99.5 %) and vortex to a clear and colourless solution.
5. Make up 1 0 ml with propylene glycol.
6. Store at 1 0-25°C, avoiding heating of any kind.
This formulation is administered into the subcutaneous layer of the skin.
The term "lower gastrointestinal tract" means here the lower part of the small intestine (ileum) and the colon. The term "enteric coating " means here a coating surrounding the core, the solubility of the coating being dependent on the pH in such a manner that it prevents the release of the drug in the stomach but permits the release of the drug at some stage after the formulation has emptied from the stomach.
Pharmaceutically acceptable refers to those properties and/or substances, which are acceptable to the patient from a pharmacological/toxicological point of view including bioavailability and patient acceptance or to the manufacturing chemist from a physical- chemical point of view regarding composition, formulation, stability and isolatability.
The terms "comprise, comprised and comprising" and the terms "include, included and including " are used interchangeably in this specification and are to be afforded the widest interpretation.
The invention is not limited to the embodiments described above, but may be varied in both construction and detail within the scope of the claims.