Mucoadhesive Drug Delivery Systems

Mucoadhesive systems are new drug delivery mechanisms that are considered highlyfavorable in recent years due to the ability to stick and stay on the mucus andrelease their drug content in a sustained manner. Drug delivery through the mucosa is agood route for a large population of patients especially for those with swallowing problems.This route has important advantages over the oral route, including bypassing hepaticfirst pass metabolism and avoiding the drug degradation within the gastrointestinal tract.Mucoadhesive dosage forms can be prepared in various forms, such as tablet, gel, oral film,spray, viscous solution and micro/nanoparticle, and can be used in drug delivery throughthe oral, intestine, ocular, nasal, vaginal, and other mucosal routes. The most importantcomponent of these systems is the polymer. Mucoadhesive polymers, in addition to actingas the mainstay of these formulations, also control the release and penetration of the drug,thereby contributing to the therapeutic benefits of these systems. Hence, mucoadhesivecharacteristics include factors related to bioadhesive polymers and the medium in whichthe polymers reside. In this article, the mucoadhesive systems; various types of dosageforms; mechanism and theories of mucoadhesion and factors affecting mucoadhesion arediscussed.