DRUG-DELIVERY USING BUCCAL-ADHESIVE SYSTEMS

The buccal mucosa has been investigated for local drug therapy and the systemic delivery of therapeutic peptides and other drugs that are subjected to first-pass metabolism or are unstable within the rest of the gastrointestinal tract. The mucosa of the oral cavity presents a formidable barrier to drug penetration, and one method of optimising drug delivery is by the use of adhesive dosage forms. Mucosal-adhesive materials are hydrophilic macromolecules containing numerous hydrogen-bond-forming groups. They have been called ''wet'' adhesives in that they require moisture to become adhesive and this may be supplied by the saliva; the latter may also act as the dissolution medium. Various buccal-adhesive formulations have been investigated with a view to delivering drugs locally or systemically. If the buccal route is to be used for the systemic delivery of large macromolecules, then a penetration enhancer incorporated into an adhesive dosage form may be a possible approach.