VOLUME 19 NUMBER 1 (January to June 2026)

Impact of varied polymer ratios on the physicochemical characteristics and release profiles of a matrix-type transdermal patch of simvastatin

Simvastatin’s (SMV) physicochemical properties, such as poor aqueous solubility and low bioavailability (< 5%), limit its biomedical applications. Transdermal delivery is one of the viable options that can improve its clinical use. This study aimed to evaluate the effect of varying the ratios of polyvinyl alcohol (PVA) and hydroxypropyl cellulose (HPC) on the physicochemical characteristics and release behavior of an SMV-loaded matrix-type transdermal patch. The developed patch was a binary matrix system, with an acrylate polymer providing adhesive properties and PVA alone as a backing membrane. The patches were then characterized in terms of SMV content, thickness, weight, moisture content, and folding endurance. The results demonstrated consistent SMV content and minimal variation in thickness and weight across formulations, indicating formulation uniformity. Polymer composition significantly influenced mechanical integrity and drug release behavior. Among the formulations evaluated, F1, with PVA/HPC ratio of 85:15, exhibited favorable physicochemical properties, controlled early-stage release, and a reproducible release rate consistent with sustained-release behavior. The study demonstrates that appropriate balancing of PVA and HPC in a binary matrix system enables controlled in vitro release of SMV and yields transdermal patches with acceptable formulation quality, providing a foundation for further optimization and transdermal performance evaluation including pharmacokinetic profile and drug permeation using in vivo studies.