ORAL CAVITY AS A SITE FOR BIOADHESIVE DRUG-DELIVERY

Accessibility of the oral cavity makes it a potentially attractive route for drug delivery. However, rapid removal of conventional delivery systems, primarily through copious salivary flow, and the relative impermeability of the buccal tissue are clear impediments to successful use of this route. Bioadhesive polymers can overcome the removal issue and can be coupled with penetration enhancers to generate a novel and successful delivery system for both local and systemic drug delivery. The present review examines factors influencing the disposition of drugs and delivery systems in the oral cavity as well as pertinent biological barriers. It also provides the theoretical and practical basis of bioadhesives in oral mucosal drug delivery systems, as well as the limited studies on penetration enhancers for this tissue. Finally, future trends are discussed.