Mucoadhesive drug delivery systems are widely used for local and/or systemic delivery of medicaments through the mucosal covered organelles. Drug delivery through transmucosal route is a promising area for continued research for achieving controlled release with enhanced bioavailability over longer periods of time, and for drug targeting to various sites in the body. The attractiveness of transmucosal drug delivery systems has led the formulation scientists to research activities for the development of mucoadhesive polymers having the desired characteristics. The review focuses on various developments in mucoadhesive polymers ranging from first generation charged hydrophilic polymers to more specific second generation polymers lectins, thiomers and others. Also enhancement of mucoadhesiveness of polymers incorporated in the drug delivery system has been discussed. Various methods such as addition of mucoadhesive excipient, conjugation, copolymerization, coating, chemical modification, charge induction, or co-mixing could be employed for enhancing the mucoadhesive strength of the polymeric materials.
Key words: Mucoadhesion; drug delivery; lectins; mucoadhesive polymers; thiomers