Permeation of topically applied caffeine through human skin – a comparison of <i>in vivo</i> and <i>in vitro</i> data

Abstract

The combination of FCT with the Franz diffusion cell represents a valuable method to investigate follicular penetration in vitro. Nevertheless, in vivo experiments should not be abandoned as in vitro, structural changes of skin occur and blood flow and metabolism are absent, probably accounting for reduced penetration rates in vitro.