Development and Evaluation of HPMC Based Matrices for Transdermal Patches of Tramadol

Abstract

A matrix dispersion type transdermal delivery system of tramadol was designed and developed using different concentrations and polymeric grades of Hydroxypropyl Methylcellulose (HPMC K4M, K15M & K100M). Formulations were selected on the basis of their drug release content and release pattern. Films were evaluated for their physicochemical characteristics, followed by in vitro and in vivo evaluation. The possible drug-polymer interaction was studied by FTIR, DSC and X-RD studies. These were evaluated for in vitro dissolution characteristic using Cygnus' sandwich patch holder. The drug release followed Higuchi kinetics (r = 0.979–998; P < 0.001). In vivo evaluation was carried out on healthy rabbits of either sex, following balanced incomplete block design. The in vitro dissolution rate constant, dissolution half life and pharmacokinetic parameters generated from plasma (tmax, Cmax, AUC(s), t1/2, Kel, and MRT) were evaluated statistically by two-way ANOVA. Statistically a good correlation was found between percent of drug absorbed from patches versus AUCs. Percent of drug dissolved at a given time versus plasma drug concentration correlated statistically. The results of this study indicate that the polymeric matrix type transdermal films of tramadol hold potential for transdermal delivery on the basis of their in vitro and pharmacokinetic results.