Evaluation method to measure integrity of oral mucosa epithelium for permeation studies

Abstract

In vitro permeation studies are commonly performed to evaluate topical formulations aiming at skin or mucosal applications. Pig tissues are typically used as barriers for these experiments due to its similarities to human tissues. Considering topical application at oral mucosa, pig esophageal or buccal epithelium are the most used barrier models. However, preparation method, storage conditions and evaluation of integrity of such tissues are poorly described in the literature. Thus, the aims of the present study are: to stablish an evaluation method to determine pig esophageal and buccal mucosa epithelium integrity by using resistivity measures; to compare their integrity prepared by two different methods described; to compare their fresh permeability to that of frozen tissues in order to confirm their interchangeability for in vitro permeation studies as well as to confirm their integrity after freezing. Pig esophageal and buccal epithelium will be prepared by two different methods and will be placed in Franz type diffusion cells filled with artificial saliva. An electrode made of Ag/AgCl will be placed into each compartment, in contact to a signal generator and a multimeter. Data will be evaluated for distribution and homogeneity and will be submitted to proper statistical tests, with significance level of 5%.