A Brief View on Antihypertensive Drugs Delivery through Transdermal Patches

Transdermal Drug Delivery System (TDDS) is one of the systems lying under the category of controlled drug delivery, in which the aim is to deliver the drug through skin in a predetermined and controlled rate. Hypertension is one of the common disorder for the mankind. It is not a disease in itself, but is an important risk factor for cardiovascular mortality and morbidity. The present article delivers a brief view on the work been done to increase the bioavailability of various antihypertensive drugs by formulated and delivered as transdermal patches. The different drugs includes carvedilol, metoprolol, atenolol, propranolol, labetolol, verapamil, indapamide, losartan, bisoprolol, timolol maleate, nicardipine hydrochloride, captopril, clonidine, pinacidil, nitrendipine, nicorandil, diltiazem hydrochloride, lisinopril, nifedipine, amlodipine, valsartan, enalapril maleate. INTRODUCTION: More recent approach to drug delivery is to deliver the drug into systemic circulation at a predetermined rate which is known as controlled release drug delivery system. Such systems helped to overcome the side effects associated with conventional system of medication, which require multidose therapy 1, . The development of technology for release of drug at controlled rate into systemic circulation using skin as port of entry has become popular for various reasons . Transdermal drug delivery system (TDDS) are adhesive drug containing devices of defined surface area that delivers predetermined amount of drug to the intact skin at the preprogrammed rate 4, . The transdermal delivery has gained importance in the recent years. The TDDS has potential advantages of avoiding hepatic first pass metabolism, maintaining constant blood levels for longer period of time resulting in a reduction of dosing frequency, improved bioavailability, decreased gastrointestinal irritation and improved patient compliance . Since the early 1980s, transdermal patch dosage form of transdermal therapeutic system (TTS) has been available commercially. Such a system offers a variety of significant clinical benefits over other conventional systems. Therefore the TTS is of particular clinical significance for the prevention and long-term treatment of chronic diseases like hypertension . Some of the antihypertensive drugs have already been formulated and evaluated as transdermal patches but most of them still been unexplored. Transdermal formulation of antihypertensive drug is promising aspect in near future. Mortality from heart diseases increases dramatically with age. Hypertension is one of the main causes of heart disease and, in recent years, the age adjusted hypertension and hypertensive disease death rates have been increasing . Consequently, the prevention and treatment of hypertension is of major social significance . Hypertension is defined conventionally as a sustained increase in blood pressure 140/90 mm Hg, a criterion that characterizes a group of patients