Abstract

Purpose:“Skin care” refers to the general concept of maintaining the homeostasis of the skin. Ceramide, the main lipid constituent of the stratum corneum, is important in maintaining the barrier function of the skin. In this study, skin care formulation containing ceramide was prepared and evaluated the effectiveness for skin treatment. Methods: We used polarized microscopy to demonstrate that an equimolar mixture of optically active ceramide 2 and cholesterol forms a lamellar structure. X-ray diffraction profiles also showed a regular lattice in the equimolar mixture of optically active ceramide 2 and cholesterol. Results: The barrier function against water evaporation was dependent on the amount of lipids adsorbed to an experimental membrane. The mixed lipids were more effective in preventing water evaporation than ceramide 2 or cholesterol alone, and the equimolar mixture of ceramide 2 and cholesterol was most effective. To evaluate the recovery of the barrier function of damaged skin, we conducted an in vitro skin permeation study of ketoprofen, which simulates a foreign substance absorbed into the body through the skin. The cumulative amount of permeated ketoprofen was used as an index of the barrier function, and was significantly lower 3 h and 6 h after its administration to skin treated with the skin care formulation than to skin treated with a placebo. Conclusion: The skin care formulation used in this study is effective in preventing skin permeation by foreign substances.


Keywords:  Skin care formulation   Ceramide 2   Cholesterol   X-ray diffraction analysis   Polarized microscopy