FORMULATION AND EVALUATION OF ANTHRALIN MICROEMULSION GEL USING KARANJ OIL

The present research work was conducted to formulate and evaluate Anthralin microemulsion gel using Karanj oil with an objective of improving solubility of the Anthralin. The pseudo ternary phase diagrams were developed for combinations of Karanj oil as the oil phase, Span-20 as surfactant and as Capryol 90 as cosurfactant using water titration method. Microemulsions obtained were analyzed for topical permeability of anthralin using Franz diffusion cell through an excised rat skin. Higher in-vitro permeation was observed from Karanj oil based microemulsion (ME1) having ratio of 1:1. Thus it was selected for further formulation studies. The developed microemulsion was characterized for globule size, polydispersibility index and results were found be 50 nm and 0.341 respectively. Centrifugation studies were carried out to confirm the stability of the developed formulation. The formulation was thickened with a gelling agent carbopol 940, to yield a gel with desirable properties facilitating the topical application. The developed microemulsion gel was characterized for pH, spreadability, refractive index and viscosity. Optimized formulation was then subjected to in-vitro drug releasescreening in comparison to currently available marketed formulation of anthralin. Optimized microemulsion gel (MEG1) formulation was found to exhibit significant anti-psoriatic activity as compared to marketed formulation. Thus the present study indicates that microemulsion gel can be a promising vehicle for the topical delivery of anthralin.