Skin ceramides based systems in transdermal drug delivery and skin care

The skin barrier function is attributed mainly to skin lipids in which ceramides are the key component. Ceramides are heterogeneous group of sphingolipids, contributing to cell adhesion, epidermal differentiation and skin hydration. Reduction in ceramides level was linked to many skin disorders. They are thus incorporated in various formulations to restore disrupted skin barrier. They were utilized as skin emollient for dry skin and as adjuvant therapy in eczema, psoriasis, rosacea and acne. Unfortunately, exogenous ceramides lack the ability to invade the stratum corneum reaching the lipid lamellae. Incorporation of ceramides into delivery systems can enhance their effectiveness by delivering significant levels to the active site. The ability of ceramides and other skin lipids to assemble in the form of vesicular structure has been also employed for skin drug delivery. This chapter summarizes the applications of skin ceramides in skin care and dermal or transdermal drug delivery.