DEVELOPMENT OF CONTROLLED RELEASE TRANSDERMAL FILMS CONTAINING ANTHRALIN

Abstract

Anthralin is an effective antipsoriatic agent widely used in the treatment of chronic skin disorders such as psoriasis; however, its therapeutic application is limited due to poor patient compliance, skin irritation, and the need for frequent administration. The present study was undertaken to develop and evaluate controlled release transdermal films containing Anthralin in order to enhance drug release control, improve therapeutic efficacy, and prolong drug delivery through the skin. Pre-formulation studies of Anthralin were carried out to determine its physicochemical properties, including organoleptic characteristics, solubility, melting point, λ max determination, calibration curve analysis, and FTIR spectroscopy. Anthralin exhibited maximum absorbance and showed compatibility with the selected excipients used in the transdermal patch formulation. The transdermal films were prepared by the solvent casting method using combinations of Eudragit L, polyvinylpyrrolidone (PVP), hydroxypropyl methylcellulose (HPMC), polyethylene glycol 400, Tween 20, methanol, and glycerin. Six formulations (TPF1–TPF6) were prepared by varying the polymer composition. The prepared transdermal films were evaluated for folding endurance, tensile strength, percentage elongation, thickness uniformity, drug content, and in vitro drug release studies. Among all formulations, TPF5 exhibited the most desirable physicochemical characteristics; including excellent flexibility, tensile strength (25 kg/cm²), percentage elongation (42%), and maximum drug content (95.78%). The optimized formulation also demonstrated a sustained and controlled drug release profile with 95.06% cumulative drug release over 11 hours. Drug release kinetics of the optimized formulation was analyzed using zero-order, first-order, Higuchi, and Korsmeyer–Peppas kinetic models. The release profile showed the highest correlation with the zero-order kinetic model (R² = 0.976), indicating concentration-independent and controlled drug release. The Higuchi model also demonstrated good linearity, suggesting diffusion-controlled release behavior from the polymeric matrix. The overall findings of the study indicate that the developed Anthralin transdermal films possess satisfactory physicochemical properties, controlled drug release characteristics, and excellent formulation stability. Therefore, the optimized transdermal patch formulation can be considered a promising alternative drug delivery system for the effective management of psoriasis and related dermatological conditions.