Pharmacological activities of anti-hypertensive drug delivery through a transdermal patch – a brief review

Abstract

One of the methods falling under the category of controlled drug delivery is the transdermal drug delivery system (TDDS), which is designed to distribute the medicine via the skin at a predefined and regulated pace. Hypertension is one of the largest death-causing diseases in mankind. Since it is a chronic disease, it required continuous treatment. The disadvantages of antihypertensive drugs such as more frequent administration, extensive first-pass metabolism and variable bioavailability, making them an ideal candidate for transdermal drug delivery systems. This article is dedicated to reviewing antihypertensive transdermal patches from the perspective of enhancing bioavailability and improving patient compliance. The various antihypertensive drugs considered in the review include timolol maleate, nicardipine hydrochloride, captopril, verapamil hydrochloride, nifedipine, propranolol hydrochloride, diltiazem hydrochloride, amlodipine besilate and carvedilol. Clonidine was the first antihypertensive drug developed in the transdermal form. Recently, various antihypertensive transdermal patches are available in the pharmaceutical market. Most of the reported methods in the literature employed the solvent evaporation method or solvent casting method for the preparation of transdermal patches. Depending on the release required over some time, the concentrations of polymer, plasticizer and penetrant were varied.