In Vitro Models for Investigations of Buccal Drug Permeation and Metabolism

Abstract

Buccal drug delivery across mucosal lining of the cheek offers a clear advantage over the peroral dosing route by avoidance of intestinal and hepatic first-pass metabolism. However, despite offering the possibility of improved systemic drug delivery, buccal administration has been utilized for relatively few pharmaceutical products so far. One of the reasons is costly preclinical development, which includes laborious pharmacokinetic evaluation in animal models. Utilization of in vitro methodology can greatly aid in early development by offering a significant increase in the number of compounds and/or formulations that can be evaluated for their potential for buccal absorp- tion. Currently, in vitro models used for the assessment of buccal drug delivery utilize freshly isolated animal buccal mucosa as well as human buccal tissue cultures. This chapter describes the different in vitro techniques used for the evaluation of buccal drug absorption and indicates their advantages and disad- vantages.