Skin Permeability

Abstract

The human skin is primarily an organ of excretion which behaves in part like a holocrine gland. Sebum and sweat are actively excreted, and the epidermis is continuously renewed for horny layer formation in a process termed molting which takes place in 28-day cycles. Intake of substances by the skin is not necessary for human existence and is in no way related to the physiologic development of homo sapiens in the course of evolution. Due to the development of a “civilized environment” which exposes the skin to innumerable substances, including those employed for skin therapy, the investigation of skin permeability presently plays a very important role. As is the case for other routes of administration drug safety considerations in local therapy have become increasingly important.