Transdermal testing: practical aspects and methods

Interest in transdermal drug delivery has increased in recent years owing to its many advantages over other routes of administration. In order to evaluate a transdermal product effectively, three main issues need to be addressed: (1) the kind of skin model that will be used to evaluate the drug permeation; (2) the mathematical model that will be used to characterize the permeation of the drug across the skin; and (3) the diffusion apparatus that will be used to conduct the permeation study.