Diffusion in a realistic simulated model for the stratum corneum

Abstract

The outermost layer of mammalian skin, called the stratum corneum (SC), constitutes a self-healing barrier against moisture loss and ingress of foreign substances. The SC comprises flat “bricks” (50-100 micron wide and 1 micron thick corneocytes largely filled with keratins) held together by a “mortar” of 6-10 layers of lipids (100 nm thick). The corneocytes are hydrophilic, while the lipid matrix is hydrophobic. The ability and way of a chemical to pass the SC is a key point for risk assessment and development of cosmetics.