In Vivo and In Vitro Models for Assessing Drug Absorption Across the Buccal Mucosa

Abstract

The buccal mucosa serves as an attractive site for the systemic delivery of many drugs, including peptides and proteins, because of its inherent permeability and the avoidance of intestinal and hepatic first-pass effects. In order to assess the potential of the buccal mucosa to act as a site of drug absorption in preclinical drug discovery and development, various models have been used. This chapter focuses on the in vivo and in vitro methods that are available to assess buccal mucosal drug absorption, with an emphasis on the advantages and limitations associated with each of the models available and the issues associated with choice of animal tissue used in preclinical drug absorption studies. Most of our work in this field has been performed using porcine buccal mucosa in modified Ussing chambers, and the reader is referred to the appendix (available online) for a comprehensive protocol on this technique.