Anna Pawlik-Gałczyńska, Artur Owczarek, Janusz Pluta

Skóra jako droga podania substancji leczniczych. Część I. Budowa skóry. Wchłanianie leków przez skórę

Skin as a way for drug substances delivery. Part 1. Skin structure and mechanisms of skin permeation. Human skin has unique properties of which functioning as a physicochemical barrier is one of the most apparent. The skin has two main layers: the epidermis, which is the outermost layer of the skin, covering the dermis that is the active part of the skin, holding the hair muscles, blood supply, sebaceous glands and nerve receptors. The skin is a very heterogeneous membrane and has a variety of cell types, but the layer that controls the penetration of drug is called the stratum corneum. The permeation of the drug through the skin has several routes: transcellular, intercellular and appendageal. The intercellular spaces consist of a mixture of lipids- ceramides, free fatty acids and cholesterol that are structured in bilayers. Transdermal drug delivery through the skin can either be passive, relying on drug diffusion across the skin, or actively driven by application of an electric field. Various potential mechanisms to enhance drug penetration through the skin are altered.