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 su bjected to first-pass metabolism or are unstable within the rest of th e gastrointestinal tract. The mucosa of the oral cavity presents a for midable barrier to drug penetration, and one method of optimising drug delivery is by the use of adhesive dosage forms. Mucosal-adhesive mat erials are hydrophilic macromolecules containing numerous hydrogen-bon d-forming groups. They have been called ''wet'' adhesives in that they require moisture to become adhesive and this may be supplied by the s aliva; the latter may also act as the dissolution medium. Various bucc al-adhesive formulations have been investigated with a view to deliver ing drugs locally or systemically. If the buccal route is to be used f or the systemic delivery of large macromolecules, then a penetration e nhancer incorporated into an adhesive dosage form may be a possible ap proach.