Abstract
The buccal mucosa has been investigated for the local drug therapy and the systemic delivery of potent peptides, proteins, and other small drug molecules that are subjected to hepatic metabolism and enzymatic degradation in the gastrointestinal tract. Being non-invasive, this route is more feasible for the delivery of therapeutic entities than that of invasive or parenteral drug administration. However, the mucosa of oral cavity represents a major barrier to drug penetration. In addition, the presence of several enzymes in saliva, salivary flow, discomfort feelings after administration of dosage forms, and bitter taste of the drugs have limited the drug delivery via the buccal cavity. Thus, extensive studies have been conducted to develop novel pharmaceutical formulations for effective buccal drug delivery. Various buccal dosage forms such as tablets, gels, and patches/films are now commercially available and have demonstrated high patient compliance. Recently, several manufacturing companies have launched new buccal drug delivery systems such as aerosol, sprays, and particulate systems and they have actively been investigated by numerous pharmaceutical scientists. If the successful development of such systems could be achieved, buccal drug delivery systems would be one of the most promising technology in the near future. In this review, we described the recent development of buccal dosage forms, anatomy of buccal mucosa, drug transport mechanisms, and formulation strategies to enhance the drug permeation through the buccal mucosa.