Review on Mucoadhesive Drug Delivery System with Special Emphasis on Buccal Route: An Important Tool in Designing of Novel Controlled Drug Delivery System for the Effective Delivery of Pharmaceuticals

Since, the last four decades, the concept of mucoadhesion has achieved a much valuable interest in the various fields of pharmaceutics. There are many advantages of mucoadhesive buccal drug delivery system that made this a novel drug delivery system for the local as well as systemic delivery of various drugs. The main advantage of this drug delivery system is that it prolongs the residence time of the dosage form at the site of application. Due to the high blood supply and relatively high permeability of the buccal mucosa, the buccal cavity is the best option for both local as well as systemic delivery of various drugs. The term bioadhesion can be defined as a phenomenon of interfacial molecular attractive forces in the midst layer of surface of a biological membrane and the natural or synthetic polymers, which allows the polymer to adhere the surface of that membrane for an extended as well as prolonged period of time. In this review we have discussed the various types of mucoadhesive dosage forms along with a brief knowledge about the various types of mucoadhesive polymers. The buccal mucoadhesive dosage forms can be either of matrix or of reservoir types. The main advantage of this route for drug delivery is that, the delivery by this route by passes the first pass metabolism of various drugs that are prone to the their hepatic first pass metabolism. This review provides the brief knowledge about the oral mucosal drug delivery by discussing briefly the structural features of mucosa, mechanism of bioadhesion, various theories of bioadhesion, general considerations in design of mucoadhesive buccal dosage forms, permeation enhancers, and the various evaluation methods along with the literature survey of the buccal mucoadhesive drug delivery system.