ABSTRACT
The human skin is exposed to many topical agents, either intentionally or by accident. The variety of these foreign agents (xenobiotics) reflects the variety of their intended uses: cosmetics are intended, in theory, to decorate the skin rather than penetrate it, while dermatological drugs such as corticosteroids are intended to act locally within the skin, with little or minimal systemic action. Some drugs, such as nitroglycerin, are not intended to act at the skin, but at distant target organs, in this case the coronary arteries.
