... that may contact the skin surface. The main lipids comprising the barrier are ceramides, cholesterol and long-chain saturated fatty acids. The ceramides are structurally heterogenous. In the human, there are 9 series of ceramides. Three of these are acylceramides consisting of long ω-hydroxy acids amide...

... a tight and effective barrier to the passage of water through the tissue, (b) the presence of corneodesmosome-bound and ceramide-hydrophobed corneocytes which influence the tortuosity of the SC and thereby the diffusion path length of water and (c) the presence of both intracellular and extracellular SC...