DEVELOPMENT OF NOVEL MICROEMULSION BASED TOPICAL FORMULATION OF CLOBETASOL PROPIONATE AND SALICYLIC ACID FOR THE TREATMENT OF PSORIASIS

Abstract

Clobetasol propionate a glucocorticoid receptor agonist is an effective anti-inflammatory, immunomodulatory and antiproliferative agent. Salicylic acid a lipophilic monohydroxybenzoic acid exhibits potent keratolytic action. The objective of this work was the development of a novel formulation containing Clobetasol propionate and Salicylic acid for improved anti-psoriatic activity. Clobetasol propionate, a BCS Class II moiety with poor permeation across the skin was formulated as a microemulsion along with incorporation of Salicylic acid in a gel base and evaluated. Microemulsion was prepared using water titration method containing oil, surfactant, co-surfactant and water. Optimized formulation was subjected to in-vitro and ex- vivo skin diffusion studies for drug release. Surface study of optimized formulation was done by scanning Electron Microscopy. In vivo anti-psoriatic activity was performed using Imiquimod Induced Psoriasis-like skin as a model. Ex-vivo drug diffusion exhibited 20.05% and 10.36% respectively for Clobetasol propionate and Salicylic acid as against a diffusion of 32.68% and 18.40% for marketed product, studied for a period of nine hours. Skin retention after 24hrs was 36.25% and 25.6% of Clobetasol propionate and Salicylic acid indicating that the developed formulation can provide sustained release. Encouraging antipsoriatic activity was obtained for the developed formulation.