Compositions and methods for enhancing the efficacy of contraceptive microbicides

Abstract

The present disclosure relates to compositions and methods for contraception that also enhance the efficacy of microbicides. Such compositions serve the dual purpose of preventing pregnancy and lessening the risk of spreading sexually transmitted diseases. More specifically, the compositions and methods relate to syngergistic contraceptive microbicide and antiviral compositions comprising a combination of a contraceptive microbicide and an antiviral agent in an acidic carrier that enhances the efficacy of both the contraceptive microbicide and antiviral agent.

What is claimed is: 
     
         1 . A contraceptive microbicide and antiviral composition comprising:
 (a) a contraceptive microbicide comprising:
 (i) a matrix-forming compound; 
 (ii) a bioadhesive compound that may be the same or different from the matrix-forming compound; and 
 (iii) lactic acid; 
   (b) 1-(6-aminopurin-9-yl)propan-2-yloxymethylphosphonic acid or a physiologically functional derivative thereof; and   (c) an aqueous-based pharmaceutically acceptable carrier;   wherein the composition has a pH of 4 or below;   wherein the composition has buffering capabilities and maintains a pH below neutral when contacted with ejaculate;   wherein the the composition is in a nonmatrix state until it comes in contact with ejaculate: and   wherein matrix formation enhances delivery of the 1-(6-aminopurin-9-yl)propan-2-yloxymethylphosphonic acid or a physiologically functional derivative thereof by facilitating prolonged release.   
     
     
         2 . (canceled) 
     
     
         3 . The composition of  claim 1 , wherein the composition further comprises a humectant. 
     
     
         4 . The composition of  claim 1 , wherein the composition further comprises a preservative. 
     
     
         5 . The composition of  claim 1 , wherein the lactic acid is L-lactic acid. 
     
     
         6 . A composition comprising:
 (a) a matrix-forming compound;   (b) a bioadhesive compound that may be the same or different from the matrix-forming compound;   (c) lactic acid;   (d) 1-(6-aminopurin-9-yl)propan-2-yloxymethylphosphonic acid or a physiologically functional derivative thereof; and   (e) an aqueous-based pharmaceutically acceptable carrier;   wherein the composition has a pH of 5.0 or below;   wherein the composition has buffering capabilities and maintains a pH below 5.0 in the presence of normal amounts of ejaculate;   wherein the composition is in a nonmatrix state until it comes in contact with ejaculate; and   wherein matrix formation enhances delivery of the 1-(6-aminopurin-9-yl)propan-2-yloxymethylphosphonic acid or a physiologically functional derivative thereof by facilitating prolonged release.   
     
     
         7 . A method for reducing the risk of spreading a sexually transmitted disease and preventing conception comprising administering an effective amount of the composition according to  claim 1 . 
     
     
         8 . The composition of  claim 6 , wherein the lactic acid is L-lactic acid. 
     
     
         9 . The composition of  claim 6 , wherein the matrix forming compound is selected from the group consisting of: alginic acid, chitosan, gellan gum, and poloxamer. 
     
     
         10 . The composition of  claim 9 , wherein the matrix forming compound is alginic acid. 
     
     
         11 . The composition of  claim 6 , wherein the bioadhesive compound is selected from the group consisting of: xanthan gum, alginic acid, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, chitosan, polycarbophil, and carbopol. 
     
     
         12 . The composition of  claim 11 , wherein the bioadhesive compound is xanthan gum. 
     
     
         13 . A composition comprising:
 (a) a matrix-forming compound selected from the group consisting of: alginic acid, chitosan, gellan gum, and poloxamer;   (b) a bioadhesive compound selected from the group consisting of: xanthan gum, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, chitosan, polycarbophil, and carbopol;   (c) lactic acid;   (d) 1-(6-aminopurin-9-yl)propan-2-yloxymethylphosphonic acid or a physiologically functional derivative thereof; and   (e) an aqueous based pharmaceutically acceptable carrier;   wherein the composition has a pH of 5.0 or below;   wherein the composition maintains a pH of 5.0 or below in the presence of normal amounts of ejaculate;   wherein the composition is in a nonmatrix state until it comes in contact with ejaculate; and   wherein matrix formation enhances delivery of the 1-(6-aminopurin-9-yl)propan-2-yloxymethylphosphonic acid or a physiologically functional derivative thereof by facilitating prolonged release.   
     
     
         14 . The composition of  claim 13 , wherein the matrix-forming compound is alginic acid and the bioadhseive compound is xanthan gum. 
     
     
         15 . The composition of  claim 13 , wherein the lactic acid is L-lactic acid. 
     
     
         16 . A composition comprising:
 (a) a matrix-forming compound consisting of alginic acid;   (b) a bioadhesive compound consisting of xanthan gum;   (c) L-lactic acid;   (d) 1-(6-aminopurin-9-yl)propan-2-yloxymethylphosphonic acid or a physiologically functional derivative thereof; and   (e) water.   
     
     
         17 . The composition of  claim 16 , further comprising a humectant selected from the group consisting of: glycerol, polyethylene glycol, propylene glycol, sorbitol, and tiracetin. 
     
     
         18 . The composition of  claim 16 , further comprising a preservative selected from the group consisting of: benzoic acid, sodium benzoate, methylparaben, ethylparaben, butylparaben, propylparaben, benzyalkonium chloride, phenylmercuric nitrate, and chlorhexidine. 
     
     
         19 . A composition comprising:
 (a) alginic acid;   (b) xanthan gum;   (c) L-lactic acid;   (d) glycerol;   (e) benzoic acid;   (f) citric acid;   (g) potassium bitartrate;   (h) 1-(6-aminopurin-9-yl)propan-2-yloxymethylphosphonic acid or a physiologically functional derivative thereof; and   (i) water.   
     
     
         20 . The composition of  claim 1 , wherein the the lactic acid is L-lactic acid and wherein the matrix forming compound and the bioadhseive compound is alginic acid.