Claims for Patent: 5,536,743

Summary for Patent: 5,536,743

Title:	Intravaginal treatment of vaginal infections with buffered metronidazole compositions
Abstract:	A non-flowing composition and method for treatment of bacterial vaginosis are disclosed. An afflicted vagina is treated with a therapeutically effective but relatively low dose of metronidazole in a composition that includes a buffer system maintaining the composition at a pH value in the range of about 3.75 to about 4.25. The composition can also be used for prophylactic purposes.
Inventor(s):	Borgman; Robert J. (Mundelein, IL)
Assignee:	Curatek Pharmaceuticals Limited Partnership (Elk Grove Village, IL)
Application Number:	08/295,242
Patent Claims:	1. A buffered non-flowing composition suitable for the treatment of bacterial vaginosis which contains metronidazole in a treatment amount of about 375 mg or less wherein the metronidazole is present in a concentration of at least about 0.1 weight percent, based on the weight of the composition, and the metronidazole is the sole active ingredient together with a buffer system in a physiologically tolerable medium; said buffer system being capable of providing a buffered pH value for the composition in the range of about 3.75 to about 4.25. 2. The composition of claim 1 wherein said buffered pH value is about 4. 3. The composition of claim 1 wherein said physiologically tolerable medium is an oil within which said buffer system and said metronidazole are suspended and/or dissolved. 4. The composition of claim 1 which is an emulsion selected from the group consisting of water-in-oil emulsions and oil-in-water emulsions. 5. The composition of claim 1 which is anhydrous but water soluble. 6. The composition of claim 1 in a gel dosage form. 7. The composition of claim 1 in a suppository dosage form. 8. The composition of claim 1 in a cream dosage form. 9. The composition of claim 1 in a foam dosage form. 10. The composition of claim 1 in the form of a unit dose containing metronidazole in an amount in the range of about 20 to about 100 milligrams. 11. The composition of claim 1 in the form of a unit dose containing metronidazole in an amount in the range of about 20 to about 40 milligrams. 12. The composition of claim 1 in the form of a unit dose containing metronidazole in an amount of about 37.5 milligrams. 13. The composition of claim 1 which has a viscosity at least sufficient to maintain said composition in a substantially non-flowable state at ambient conditions. 14. The composition of claim 1 wherein said composition contains about 0.75 weight percent metronidazole, based on the total weight of the composition. 15. The composition of claim 1 wherein the concentration of metronidazole is in the range of about 0.25 percent to about 1 percent by weight, based on the total weight of the composition. 16. The composition of claim 1 wherein the concentration of metronidazole is in the range of about 0.1 percent to about 2 percent by weight, based on the total weight of the composition. 17. A gel composition suitable for intravaginal treatment of bacterial vaginosis comprising metronidazole as the sole active ingredient in a treatment amount of about 375 mg or less wherein the metronidazole is present in a concentration of at least about 0.1 weight percent based on the weight of the composition and the metronidazole is dispersed in a buffered gelled hydrophilic and water-dispersible polyacrylic acid polymer having free carboxylic acid groups and a molecular weight in the range of about 1,250,000 to about 4,000,000 daltons; sufficient base to cause said composition to have a pH in the range of about 3.75 to about 4.25; and an aqueous solvent for said metronidazole and said base. 18. The composition of claim 17 wherein the concentration of metronidazole is about 0.75 percent by weight based on the total weight of the composition. 19. The composition of claim 17 wherein the concentration of metronidazole is in the range of about 0.25 percent to about 1 percent by weight based on the total weight of the composition. 20. The composition of claim 17 wherein the pH value of the composition is about 4. 21. The composition of claim 17 wherein said polymer is present in a range of about 0.2 percent to about 7 percent by weight based on the total weight of said composition. 22. The composition of claim 17 wherein said polymer is present in a range of about 0.5 percent to about 2.5 percent by weight based on the total weight of said composition. 23. The composition of claim 17 wherein said polymer is present in an amount of about 2 percent by weight based on the total weight of said composition. 24. The composition of claim 17 wherein said gel composition further includes a solubilizer. 25. The composition of claim 24 wherein said solubilizer is propylene glycol and is present in an amount in the range of about 2 percent to about 5 percent by weight, based on the total weight of said composition. 26. The composition of claim 25 wherein said propylene glycol is present in an amount of about 3 percent by weight, based on the total weight of said composition. 27. The composition of claim 17 wherein said gel composition further includes a preservative. 28. The composition of claim 27 wherein said preservative includes at least one paraben. 29. The composition of claim 28 wherein said preservative consists essentially of methyl paraben present in an amount of about 0.08 weight percent and propyl paraben present in an amount of about 0.02 weight percent, based on the total weight of said composition. 30. The composition of claim 17 wherein said gel composition further includes ethylenediaminetetra acetic acid in an amount in the range of about 0.01 percent to about 0.1 percent by weight, based on the total weight of said composition. 31. The composition of claim 17 in the form of a unit dose which contains about 20 to about 40 milligrams of said metronidazole. 32. The composition of claim 17 in the form of a unit dose which contains about 37.5 milligrams of metronidazole. 33. A gel composition suitable for intravaginal treatment of bacterial vaginosis which contains metronidazole as the sole pharmacologically active ingredient dispersed in an aqueous buffered gel of a hydrophilic and water-dispersible polyacrylic acid polymer having free carboxylic acid groups and a molecular weight in the range of about 1,250,000 to about 4,000,000 daltons; said metronidazole being present in the composition in a treatment amount of about 375 mg or less and a concentration of about 0.75 percent, based on the total weight of the composition, and said composition containing sufficient sodium hydroxide to cause the composition to have a pH value of about 4. 34. A method for treating bacterial vaginosis in a human patient which comprises introducing into the vagina of a patient in need of such treatment a non-flowing composition which contains metronidazole as the sole active ingredient in a treatment amount of about 375 mg or less together with a buffer system in a physiologically tolerable medium; said buffer system being capable of providing a buffered pH value in the range of about 3.75 to about 4.25, and said composition being introduced into the vagina at least once a day for a time period of at least one day. 35. The method of claim 34 wherein the concentration of metronidazole in said composition is at least about 0.1 weight percent on a total composition weight basis. 36. The method of claim 34 wherein said introducing is carried out one to three times daily over a time period of three to ten days, the total daily dose thus delivered being in the range of about 100 to about 375 milligrams of metronidazole. 37. The method of claim 34 wherein said physiologically tolerable medium comprises an oil within which said metronidazole and said buffer system are suspended and/or dissolved. 38. The method of claim 34 wherein the total dose of metronidazole administered to the patient is in the range of about 185 to about 375 milligrams. 39. A method for treating bacterial vaginosis in a human patient which comprises introducing into the vagina of a patient in need of such treatment a non-flowing composition which contains in the range of about 0.1 to about 2 weight percent, based on the total weight of the composition, of metronidazole as the sole active ingredient; said composition having a buffered pH value in the range of about 3.75 to about 4.25 and being introduced into the vagina in an amount sufficient to deliver a total amount of metronidazole in the range of about 100 milligrams to about 375 milligrams during the course of the treatment. 40. The method of claim 39 wherein the composition contains metronidazole in the range of about 0.25 to about 1 weight percent, based on the total weight of the composition. 41. The method of claim 39 wherein the composition contains about 0.75 weight percent metronidazole, based on the total weight of the composition. 42. The method of claim 39 wherein said composition is buffered to a pH value of about 4. 43. The method of claim 39 wherein the concentration of metronidazole in said composition is about 0.75 weight percent on a total composition weight basis, and is administered in an amount of about 37.5 milligrams per dose. 44. The method of claim 43 wherein metronidazole is administered one to three times daily. 45. A method for the treatment of bacterial vaginosis in a human patient which comprises introducing into the vagina of a patient in need of such treatment a buffered aqueous gel which contains in the range of about 0.1 to about 2 weight percent, based on the total weight of the composition, of metronidazole as the sole active ingredient wherein the treatment amount of metronidazole is about 375 mg or less and a buffer system providing a buffered pH in the range of about 3.75 to about 4.25. 46. The method of claim 45 wherein the pH value of the composition is about 4. 47. The method of claim 45 wherein the composition contains metronidazole in the range of about 0.25 to about 1 weight percent, based on the total weight of the composition. 48. The method of claim 45 wherein the concentration of said metronidazole in said gel composition is about 0.75 percent by weight based on the total weight of said composition. 49. The method of claim 45 wherein said therapeutically effective amount is about 20 to about 40 milligrams of said metronidazole per dose. 50. The method of claim 45 wherein said therapeutically effective amount is about 37.5 milligrams of metronidazole per dose. 51. A method for treating bacterial vaginosis in a human patient which comprises introducing into the vagina of a patient in need of such treatment about 5 grams of a buffered aqueous gel which contains about 0.75 weight percent, based on the total weight of the composition, of metronidazole as the sole pharmacologically active ingredient and at a pH value of about 4 once or twice daily for a time period of five days wherein the treatment amount of metronidazole is about 375 mg or less. 52. An article of manufacture comprising a packaging material and contained therein a pharmaceutical agent consisting essentially of metronidazole and a buffer system in a physiologically tolerable medium; said buffer system being capable of providing a buffered pH value in the range of about 3.75 to about 4.25; said pharmaceutical agent being effective for ameliorating the symptoms of bacterial vaginosis; and said packaging material comprising a label which indicates that said pharmaceutical agent can be used for ameliorating the symptoms of bacterial vaginosis in a treatment amount of about 375 mg or less. 53. The article of manufacture in accordance with claim 52 wherein said buffered pH value is about 4, the physiologically tolerable medium is an aqueous gel containing about 0.75 weight percent metronidazole, and said label indicates intravaginal administration twice daily for 5 days. 54. The article of manufacture in accordance with claim 52 wherein said buffered pH value is about 4, the physiologically tolerable medium is an aqueous gel containing about 0.75 weight percent metronidazole, and said label indicates intravaginal administration once a day for 5 days. 55. A method for preventing bacterial vaginosis which comprises intravaginal administration to a human female patient susceptible to bacterial vaginosis a prophylactic amount of a non-flowing composition which contains metronidazole as the sole active ingredient; said composition having a pH value in the range of about 3.75 to about 4.25 and containing metronidazole at a concentration of at least about 0.1 weight percent, based on the weight of the composition wherein the amount of metronidazole administered during each such prophylasix is about 375 mg or less. 56. The method of claim 55 wherein the metronidazole concentration is in the range of about 0.1 to about 2 weight percent, based on the weight of the composition. 57. The method of claim 55 wherein the metronidazole concentration is in the range of about 0.25 to about 1 weight percent, based on the weight of the composition. 58. The method of claim 55 wherein the metronidazole concentration is about 0.75 weight percent, based on the weight of the composition. 59. The method of claim 55 wherein the amount of metronidazole administered is in the range of about 20 milligrams to about 80 milligrams twice a week on non-consecutive days. 60. The method of claim 55 wherein the amount of metronidazole administered is in the range of about 30 to about 40 milligrams twice a week on non-consecutive days.