Design And Evaluation Of HPMC -Based DiclofenacSodium Transdermal Patches: Application Of 32 FactorialDesign For Optimization”

Abstract

Objective: The study aimed to develop and optimize Diclofenac Sodium transdermal patches using hydroxyl Propyl Methyl Cellulose (HPMC) as a polymer, with PEG-400 and propylene glycol as plasticizers, employing a 3² factorial design for formulation optimization.

Methods: Patches (F1–F9) were prepared via solvent casting and evaluated for physicochemical properties, drug content, mechanical strength, moisture uptake, water vapor transmission rate, in vitro drug release, and ex vivo skin permeation using human skin in a Franz diffusion cell. FTIR studies confirmed drug–excipient compatibility. The optimized batch was subjected to stability testing.

Results: All formulations showed uniform thickness (0.21 ± 0.02 to 0.28 ± 0.03 mm) and drug content (94.8 ± 0.5% to 99.2 ± 0.4%). Tensile strength and elongation at break increased with higher plasticizer concentration. The optimized batch (F9) showed maximum cumulative drug release (94.12 ± 1.25% in 24 h) and superior permeation profile (88.67 ± 1.32%). Kinetic modeling indicated Higuchi diffusion with non-Fickian release. Stability studies confirmed no significant change in physicochemical or release characteristics over 3 months.

Conclusion: HPMC-based Diclofenac Sodium patches with PEG-400 and propylene glycol as plasticizers demonstrated promising transdermal delivery potential, enabling sustained drug release and improved permeation.