Abstract
Stratum corneum, the outermost layer of skin, plays an important role on barrier function, which resists external
stimuli, and on water holding property. Stratum corneum consists of corneocyte cells and intercellular lipid layers,
which are located between corneocyte cells. The intercellular lipid layers are considered to be important in terms of
barrier and water holding property of stratum corneum. Intercellular lipid layers, consisting of ceramide and cholesterol and fatty acid, form lamellar structure to hold water in its hydrophilic moiety.
We developed pseudo-ceramide to optimize water holding property of natural ceramide. We found that sphingoshine/ceramide /water system formed intercellular lipid-like structure and that the emulsion utilizing the system showed significant improvement on skin roughness and water holding property of skin. We applied these technologies to our cosmetic products.
