Transdermal drug delivery devices

The concept of transdermal delivery is not new, but until recently, its therapeutic application was restricted to creams and ointments which are messy and difficult to apply uniformly to ensure reproducible dosing. In the late 1970s, technology was developed that permitted the construction of multicomponent devices embodying the ability to provide precise transdermal delivery in a convenient dosage form. 1 Soon thereafter, the first modern “Transdermal Drug Delivery Device” was brought to the market. This product was an adhesive skin patch capable of delivering the antiemetic scopolamine at a controlled, predetermined rate for 3 days of motion sickness prophylaxis. It has been followed by several other transdermal delivery devices. Concurrently, there has been an explosion of interest in the field of novel forms of drug delivery in general, and transdermal delivery in particular. Because pharmacokinetic and physicochemical principles involved in transdermal delivery are discussed in other sections of this publication and extensive reviews on various aspects of transdermal drug delivery 2,3 have recently appeared, here we will describe existing commercial transdermal delivery devices and will speculate on the future of transdermal delivery devices.