QUANTITATIVE EVALUATION OF HPMC POLYMER CONCENTRATION AND ITS EFFECT ON DRUG FLUX AND RELEASE KINETICS IN TRANSDERMAL PATCHES USING CETIRIZINE HYDROCHLORIDE AS A MODEL DRUG

Transdermal drug delivery systems (TDDS) represent an effective approach to conventional oral therapy by providing sustained drug release, bypassing hepatic first-pass metabolism, and improving patient compliance through non-invasive administration. However, achieving predictable drug release remains a major challenge in matrix-type transdermal systems, as drug flux is strongly influenced by polymer concentration. The present study investigates the role of polymer concentration in modulating drug flux and achieving controlled drug release in HPMC-based transdermal systems. Patches were formulated using hydroxypropyl methylcellulose (HPMC) at varying concentrations (1–5% w/w) to examine how polymer concentration regulates drug flux and drug release kinetics. Cetirizine hydrochloride was selected as the model drug due to its suitable physicochemical properties and its therapeutic relevance in allergic conditions where sustained antihistaminic activity may be beneficial. The prepared patches were evaluated through in vitro permeation studies to determine cumulative drug release and steady-state flux as indicators of drug transport across the transdermal system. The resulting release profiles were further analyzed using Higuchi and Korsmeyer–Peppas kinetic models to characterize the mechanism of drug release, while statistical comparison among the prepared patches was carried out using analysis of variance (ANOVA). Through the integration of flux determination, kinetic modeling, and statistical evaluation, this study seeks to establish a quantitative understanding of how polymer concentration can regulate drug transport in transdermal systems, supporting the development of controlled and predictable transdermal drug delivery systems.