FORMULATION OPTIMIZATION AND INVITRO EVALUATION OF ROFLUMILAST LOADED NANOSTRUCTURED LIPID CARRIER FOR PLAQUE PSORIASIS

Dr. K. Sundaramoorthy, P. Dinesh*

ABSTRACT

The present study was primarily aimed at the development and optimization of Roflumilast loaded Nanostructured Lipid Carriers (ROF-NLCs) for the topical management of Psoriasis, a chronic, immune-mediated inflammatory skin disorder requiring long-term therapy. Roflumilast, a selective Phosphodiesterase-4 (PDE4) inhibitor, exhibits therapeutic potential in psoriasis but its clinical use is limited by poor aqueous solubility and inadequate skin penetration. To overcome these limitations, ROF-NLCs were formulated using Glyceryl monostearate, Cetyl palmitate, and Oleic acid as lipid components with Tween 80 as surfactant. A 2³ factorial design was employed to optimize critical formulation parameters including lipid ratio and surfactant concentration. Pre-formulation compatibility was confirmed through FTIR studies, which indicated no significant drug–excipient interaction. Eight different formulations (F1–F8) were prepared by Hot Homogenization technique and were evaluated for particle size, polydispersity index (PDI), zeta potential, entrapment efficiency, drug content, in vitro drug release, release kinetics, morphological characterization (SEM), and stability studies. Among the prepared formulations, F5 was identified as the optimized batch, showing an average particle size of 210 nm, zeta potential of –20.5 mV, entrapment efficiency of 82.3%, drug content of 96.3% and maximum cumulative drug release of 84.8% at the end of 8 hours. SEM analysis revealed spherical particles with smooth morphology. In vitro release kinetics of F5 followed Zero-order and Hixson–Crowell models, suggesting a controlled release mechanism. Stability studies confirmed the robustness of the formulation under storage conditions. The optimized formulation (F5) of Roflumilast-loaded NLCs demonstrated favourable particle size, stability, high entrapment efficiency, and sustained drug release profile. These findings indicate that NLCs significantly enhance the solubility, stability, and skin penetration of Roflumilast, making them a promising platform for effective topical delivery in the management of psoriasis.

Keywords: Roflumilast, Nanostructured Lipid Carrier, Psoriasis, Hot Homogenization technique, Bioavailability, Phosphodiesterase-4 (PDE4) inhibitor.