Correlation between Skin Structure and Cosmetics

Among all creatures, human beings have adapted best to the natural environments for about 5 billion years. The adaptation process includes secretion of sebum which makes a thin sebum film on the skin to prevent water loss from the skin, as well as production of NMF to prevent skin damage from dry environments since sebum film itself was not enough to maintain life. However, societal developments have led to more people having abnormal functioning skin. Basic skin care products are thus intended for turning abnormal skin back to normal. Therefore the fundamental formula for basic skin care products includes substitutes found in nature for sebum and NMF. We should first know the compositions of sebum by analyzing it and find the same or similar materials to sebum from nature, which are called oily raw materials. The materials similar to NMF are called humectants. The cosmetic emulsion droplets can penetrate more effectively to the skin when they have the same lamellar structure as inter cellular lipid, which is the penetration pass way. We obtained understanding of what raw materials should be used in cosmetics and how to make it from the studies. Therefore the purpose of this lecture is for the audience to clearly understand how cosmetic products should be made and to delineate which materials are good by explaining the relationship between skin and cosmetics.