A pharmacokinetic model for percutaneous absorption

A linear pharmacokinetic model for percutaneous absorption has been derived. Following topical application, the amount of drug excreted as a function of time is found to depend upon 4 first-order kinetic processes; the physical significance of the rate constants is discussed and their interpretation proposed. The model, applied to previously published data, successfully describes the pattern of behaviour observed for the 3 drugs: testosterone, benzoic acid and hydrocortisone. It is believed that the pharmacokinetic scheme presented is both straightforward in concept and sufficiently sophisticated in design to possibly prove of general applicability for understanding the percutaneous absorption and subsequent fate of a variety of drugs.