Structures formed by epidermal lipids in vitro.

The extracellular membranous structures of stratum corneum constitute the major barrier to percutaneous penetration. These intercellular lipid lamellae are devoid of phospholipids and are unique in their lipid composition. In this article, some of the recent investigations of the structures formed by the stratum corneum lipids in vitro are discussed with relevance to the barrier function of epidermis. These studies have provided some insight into the dramatic physical changes that occur in the membranous structures of the epidermis during the formation of the stratum corneum.