Tissue-based in vitro and ex vivo models for buccal permeability studies

The oral route is the most commonly used route for drug delivery but it has some well-known limitations that have motivated the search for alternative administration routes. Thus, the buccal route has been the focus of study. Buccal drug delivery avoids the first-pass effect, presystemic elimination by the gastrointestinal tract, and adverse drug reactions. Also, because buccal administration is easily performed, it may be a good alternative to oral drug administration without compromising compliance with treatment. Therefore, buccal permeability models are essential to determine important permeation parameters, but not all models are adequate to mimic the complex human buccal mucosa. Although the oral mucosa of several animals has been tested, oral tissue from pigs is most extensively used for in vitro drug permeability studies owing to similarities with human oral mucosa. Thus, this chapter aims to provide technical guidance regarding procedures for performing buccal permeability studies using porcine buccal mucosa as a model.