Conventional dosage form have significant setbacks of poor bioavailability and frequent dosing due to hepatic first pass metabolism. Continuous intravenous infusion at a programmed rate has been recognised as a superior mode of drug delivery not only to bypass hepatic metabolism but also to maintain a constant concentration in blood for prolonged period in therapeutic range. However such a mode of drug delivery has certain risks and necessitates hospitalization and close medical supervision. Recently there has been an increasing awareness that the benefits of IV drug infusion can be closely duplicated without its potential hazards, by continuous transdermal drug administration through intact skin.
