Controlled drug delivery of diltiazem hydrochloride as transdermal patches: a novel approach on formulation evaluation in vitro and in vivo parameters

A significant effort was done to formulate transdermal patches (Paranjothi 1998) ofDiltiazem Hydrochloride (DH), a benzothiazepine calcium channel blocker, mainly meantfor the treatment of hypertension, chronic stable angina pectoris; by using hydroxy ethylcellulose, ethyl cellulose and Eudragit RLPO. Six batches of transdermal patches wereprepared by solvent casting technique in which the best formulation was found out. Thepolymers HEC, EC and Eudragit RLPO were incorporated with Diltiazem Hydrochloride invarious proportions, out of which the best formulation on the ratio [HEC: EC: EUDRAGITRLPO-1:1:2] with the drug was determined. The prepared transdermal patches werespherical, uniform in shape and white in color. The obtained transdermal films wereevaluated for physico-chemical characteristics, in vitro release profile and in vivo evaluationin albino mice. Higuchis plot studies revealed that the predominant mechanism of drugrelease was diffusion.