COMPARATIVE PERMEABILITY OF HUMAN VAGINAL AND BUCCAL MUCOSA TO WATER

There is currently a resurgence of interest in the oral mucosa as a ro ute for drug delivery. The relative scarcity of human oral mucosa for in vitro permeability studies, and the fact that vaginal mucosa is his tologically similar and more abundant than the former, caused us to co mpare these 2 tissues with respect to their barrier properties to wate r. Specimens of fresh, clinically-healthy human Vaginal and buccal muc osa from non-smokers were taken from excised tissue obtained during Va ginal hysterectomies and Various oral surgical procedures. Biopsies fr om each specimen were mounted in flow-through diffusion cells and thei r permeability to tritiated water determined using a continuous flow-t hrough perfusion system. Specimens were examined histologically before and after permeability experiments and similarities between vaginal a nd buccal tissues verified. No statistically significant differences b etween mean steady state flux Values (10-16 h) for vaginal and buccal mucosa, respectively, were found. Human vaginal mucosa is therefore as permeable as buccal mucosa to water, and these results warrant furthe r investigation with other compounds to establish whether vaginal muco sa may be a useful model for buccal mucosa for drug permeability studi es.