Acyclovir is an anti-viral, which has been used in the treatment of vaginal disorder. Acyclovir is almost completely absorbed after oral administration but has low bioavailability of about 10-15% because of first pass metabolism. As first pass metabolism removes approximately 85-90% of the drug, so for clinical efficacy of the drug it should be frequently administered. Hence an attempt has been made to produce sustained release dosage form of the acyclovir which can be specifically employed for the treatment of vaginal disordered by Herpes simplex virus. The Mucoadhesive tablets of acyclovir has been prepared by direct compression methods and evaluated for various parameter such as thickness, friability, hardness, drug content, weight variation, swelling index, surface pH, bioadhesive force, bioadhesive time, drug release etc. The kinetic data was applied to the optimized formulations. So formulation of acyclovir in a vaginal mucoadhesive tablet dosage form will decrease the frequency of administration, which can lead to an improvement in patient adherence and thereby improving its clinical efficacy.

Mucoadhesive drug delivery systems are delivery systems which utilize the property of bioadhesion of certain polymers which become adhesive on hydration and hence can be used for targeting a drug to a particular region of the body for extended periods of time. Many of these delivery routes, particularly those through the nasal, ocular, reproductive and gastrointestinal system, involve contact with mucosal surfaces. The gastrointestinal route has been particularly popular among medical staff and patients alike. Although convenient, unfortunately, this route can be very inefficient for a number of reasons, including too rapid transit of the drug-containing delivery system past the optimum site for absorption, which is normally the small intestine and to a lesser degree the stomach and colon. Mucoadhesive formulations use polymers as the adhesive component. Mucoadhesive drug delivery systems are available in the form of tablets, films, patches, and gels for oral, buccal, nasal, ocular, vaginal, rectal and topical routes for both systemic and local effects. This review article represents the various aspects of vaginal drug delivery system, bioadhesion mechanism, Theory of bioadhesion, factors affecting bioadhesion, various types of vaginal formulation etc.