Development of Matrix Type Transdermal Patches of Lacidipine: Evaluation of Physicochemical, in vitro, ex vivo and Mechanical Properties

Transdermal patches were developed for a low oral bioavailable drug, lacidipine (LCDP) employing ethyl cellulose/Eudragit RL100 and polyvinyl pyrollidone (PVP) as polymeric matrices. The effect of binary mixtures of polymers on physicochemical properties such as thickness, moisture absorption and moisture content; in vitro release, ex vivo permeation and mechanical properties was evaluated. Ex vivo permeation studies across rat abdominal skin were conducted using Franz diffusion cells. Binary mixture of polymer, ethyl cellulose-PVP and Eudragit RL100-PVP at 2.5:7.5 (LE4) and 5:5 (LP3) showed maximum amount of drug release and ex vivo permeation (LE4, 2282.3 μg; LP3, 2765.7 μg). Different kinetic models used to interpret the release kinetics and mechanism indicated that release from all formulations followed zero order release kinetics with fickian diffusion pattern. The flux of LE4 and LP3 formulations showed a flux of 17 and 21.1 μg cm² h⁻¹, which could meet the target flux. The tensile strength of LE4 and LP3 were found to be 0.6 and 1.1 Kg mm⁻². Matrix type transdermal patches having suitable mechanical properties for LCDP were developed and evaluated.