Bioadhesive Polymers for Drug Delivery Applications

The bioadhesive polymers applicable in drug delivery systems are considered in this chapter. The limitations encountered with conventional drug delivery systems are tackled through bioadhesive/mucoadhesive drug delivery systems which curtail drug dosing frequencies, offering extended and consistent drug release with better drug bioavailability. In bioadhesive drug delivery, a polymeric drug carrier is trapped to epithelial tissue while mucoadhesion entails the sticking of a polymeric drug carrier to mucous membranes. Epithelial tissues or mucous membranes are components of various parts of the body and constitute potential sites for bonding of a bioadhesive/mucoadhesive drug carriers and have become necessary in the application of bioadhesive/mucoadhesive drug delivery systems. These mode of drug deliveries have become valuable in handling drugs that are not flexible in oral or other conventional mode of administration especially those that are acid degradable or experience the first-pass metabolic pathway. The capability of a dosage form to fit into the bioadhesive/mucoadhesive drug delivery systems is based on several factors, including the nature of the mucosal tissue and the physicochemical behaviour of the polymeric formulation. This chapter reviews several aspects of bioadhesion/mucoadhesion, their mechanisms, bioadhesive/ mucoadhesive polymers, factors affecting them and their classification among others.