REVIEW ON: BUCCAL BIOADHESIVE DRUG DELIVERY SYSTEM

The oral route is most ancient as well as preferred by the patient being convenient to take. However, per oral administration of drugs has shortcomings such as hepatic first-pass metabolism and enzymatic degradation within the GI tract which comprehend a hindrance to the absorption of peptides and proteins group of drug. On the contrary of per oral route, mucosal layer (nasal, rectal, vaginal, ocular and oral cavity) are often considered as potential sites for drug administration and having distinct advantages for systemic drug delivery. These advantages include possible liver bypass effect, avoidance of presystemic elimination within the GI tract with improved absorption and hence better bioavailability. Although, the mucosal surface as a site for drug delivery has certain drawback too as the lack of dosage form retention at the site of absorption. Consequently, the concept of bioadhesive polymers has extensively been employed in the development of transmucosal drug delivery systems. If these polymers are then incorporated into buccal formulations, drug absorption by buccal mucosa layers may be enhanced or the drug may be released for extended period of time as per the formulation design at a particular site. This review describes historical background of muco-adhesive system, different polymers used, permeation enhancers’, theory and mechanism of muco-adhesion, in vitro and in vivo methods of bioadhesion.