MUCOADHESIVE DRUG-DELIVERY SYSTEMS

Mucoadhesion in drug delivery systems has recently gained interest amo ng pharmaceutical scientists as a means of promoting dosage form resid ence time as well as improving intimacy of contact with various absorp tive membranes of the biological system. Besides acting as platforms f or sustained-release dosage forms, bioadhesive polymers can themselves exert some control over the rate and amount of drug release, and thus contribute to the therapeutic advantage of such systems. This paper d escribes some aspects of bioadhesion such as mucus layer, mucoadhesion , and theories of bioadhesion to explain the adhesion mechanism. The f actors important to mucoadhesion, the methods used to study bioadhesio n, and bioadhesive polymers are described. The methods that evaluate t he mucoadhesive dosage forms and finally the bioadhesive drug delivery systems designed for several therapeutic purposes are presented.