ABSTRACT

In recent years, proteins and peptides are emerging as a major class of therapeutic agents. Pharmaceutical scientists are faced with the challenges of selection of a suitable route of drug delivery and formulation of these bioengineered drugs. Excellent accessibility to the buccal mucosa makes application of the dosage form painless, precisely located, and easily removable without discomfort at the end of the application period. The oral cavity consists of a pair of buccal mucosae. The epithelium consists of approximately 40 to 50 layers of stratified squamous epithelial cells. The epithelial cells originate from a layer of basal cells, which are cuboidal in shape, undergo continuous mitosis, and move to the surface. Keratinization and composition, although not major factors, of the various oral mucosae affect systemic mucosal drug delivery. Additional factors such as absorptive membrane thickness, blood supply, blood/lymph drainage, cell renewal rate, and enzyme content will also govern the rate and extent of drug absorption into the systemic circulation.