Intercellular lipids of the stratum corneum (SC) form a lamellar structure (LS) that consists mainly of ceramides, cholesterols and fatty acids as amphiphilic substances, and that demonstrates significant skin barrier function.1, 2 This natural liquid crystalline (LC) structure has a bi-continuous composition of water and amphiphilic lipids, and simultaneously possesses high moisturizing and water loss prevention effects.3
In the past, much work has been devoted to preparing emulsions using the self-organization of structures formed in mixed systems of surfactants and amphiphilic lipids—such as fatty alcohols, fatty acids, lecithin, polyglycerol alkyl ethers and mono alkyl phosphates, among others—to develop bio-mimetic LC emulsions.4-7 In relation, Suzuki et al. disclosed work in this field describing a bio-mimetic lamellar LC system based instead on synthetic ceramides.8 Figure 1 exemplifies a schematic illustration of oil droplets surrounded by liquid crystals, forming LC o/w emulsions.