SUMMARY
The main aim of pharmaceutical research is steadily shifted from the development of new chemical entities to the development of novel drug delivery system of existing drug molecule to maximize their effectiveness in terms of therapeutic action, patent protection, patient compliance and reduced adverse effects. In the recent years the interest is growing to develop a drug delivery system with the use of a mucoadhesive polymer that will attach to related tissue or to the surface coating of the tissue for targeting various absorptive mucosa such as ocular, nasal, pulmonary, buccal, vaginal, etc. This system of drug delivery is called mucoadhesive drug delivery system. The buccal region of oral cavity is an attractive target for administration of drug of choice. Buccal drug delivery involves the administration of desired drug through the buccal mucosal lining of the oral cavity. Other than the common advantages of novel drug delivery systems, buccal mucosa has several specific advantages like, faster and richer blood flow, lesser thickness of the buccal mucosa and increased permeability, low enzymatic activity in the buccal mucosa and versatility in designing unidirectional release systems to overcome the first-pass metabolism and subsequent low bioavailability of the drug. Key words: Buccal mucosa, mucoadhesion, permeation enhancers, novel drug delivery, buccal adhesive polymers