United States Patent:  6,017,521

Assignee:  Columbia Laboratories, Inc. (Aventura, FL)

Filed:  October 16, 1997

The present invention relates to the use of a bioadhesive aqueous composition to control the pH of the vagina to alleviate microorganism growth and feminine odor such as presented by bacterial vaginosis. The composition contemplated herein comprises water and an acidic polymer, specifically one wherein 80% of the monomers contain at least one carboxyl group [--COOH] and wherein the polymer is cross-linked so as to be water-swellable, but water-insoluble. The composition of the present invention is additionally a bioadhesive providing for a long-lasting benefit and control of vaginal pH.

SUMMARY OF THE INVENTION

The present invention provides a composition and method for inducing and maintaining an acidic pH in the vagina in order to control the growth of microorganisms that cause vaginosis and vaginal odor. In accordance with the method, the cells lining the vagina are contacted with an aqueous buffering composition that comprises water, an effective pH buffering amount of a water-swellable but water-insoluble cross-linked bioadhesive polycarboxylic acid polymer and, preferably, a thickening/smoothening amount of a consistency-enhancing agent. The pH buffering polymer is a water-swellable, but water-insoluble, cross-linked carboxy-functional polymer. The polymer is used to contact the cells lining the vagina of a mammal, preferably a human.

The pH buffering polymer preferably contains a plurality of monomers of which at least about 80 percent, and preferably at least about 90 percent, contain at least one carboxyl functionality [--COOH], and a cross-linking agent, present in an amount so as to make the polymer water-swellable but water-insoluble. The consistency-enhancing agent is a water-dispersible, and preferably, a water-soluble, non-ionic or anionic polymer.

As noted above, the pH buffering polymer is water-insoluble, which means that less than 1 percent of it dissolves in water, and water-swellable, which means that it generally can absorb about 40 to about 100 times its weight in water. The polymer of the present invention may be contrasted with the water-swellable polymers, that can absorb considerably in excess of 100 times their weight in water, which are not contemplated by the present invention.

In practice, it is preferred that the dry pH buffering polymer is sized to pass through a No. 400 sieve screen (U.S. Standard Sieve Series). It is also preferred that, when in use, the buffering particles be dispersed in a physiologically tolerable diluent, and particularly, an aqueous diluent. The diluent solution may also contain other ingredients useful for application to the vaginal lining.

One advantage of the present invention is that the active pH buffering component of the composition is a bioadhesive, such that, when applied topically to the cells lining the vagina, the composition will remain in place for up to about 2-3 days, providing for long-lasting treatment. Thus, fewer applications of the pH buffering bioadhesive polymer are required for full efficacy than with previously known topically applied compositions to obtain a satisfactory result.

Another advantage of the present invention is that, even though the compositions are acidic in nature, they are not noticeably irritating to the vaginal mucosa with which they are in contact.

A further advantage is that the need for antibiotics to treat vaginosis is reduced, since the acidic environment established in the vagina by the bioadhesive polymer controls growth of the microorganisms causing vaginosis. Moreover, the acidic environment also produce protonation of the odoriferous amines resulting in the production of non-volatile and non-odoriferous salts of the odor-producing amines in the vagina, thereby decreasing the offensive odor resulting from vaginosis.

A still further advantage is that the polymer of the present invention provides moisturization to the vagina.

Claim 1 of 13 Claims

1. A method of treating bacterial vaginosis comprising (a) topically contacting the luininal surface of vaginal epithclial cells with an effective pH buffering amount of an aqueous compositions comprising water and an effective amout of a water-swellable, but water-insoluble, cross-linked pH buffering bioadhesive polymer wherein at least 80% of the monomers comprising said polymer contain at least one carboxyl group; and (b) maintaining said contact for a time period sufficient to lower the pH of the vagina to an acidic pH, said composition being free of treating agent.

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