FORMULATION AND CHARACTERIZATION OF SOLID MICROEMULSION OF DARUNAVIR FOR ENHANCED SOLUBILITY AND DISSOLUTION

The solid microemulsion of Darunavir, a promising antiretroviral drug, is attempted in the present work for enhancing the solubility and dissolution rate. For this purpose, solubility of Darunavir was determined in various oils, surfactant and cosurfactants. Pseudo-ternary phase diagrams were constructed to identify the microemulsion existing zone. The optimized formulation consisted of 65% of Capmul MCM, 20% of Cremophore RH 40: Transcutol P (1:1) and distilled water. The optimized microemulsion formulation was characterized for its refractive index, % transmittance, pH, viscosity, drug content and particle size. Particle size of the optimized microemulsion formulation was found to be 40.68 nm. Various adsorbents were incorporated in the optimized liquid microemulsion to get solid microemulsion. The solid microemulsion with aerosil 200 was optimized because of very low concentration (1:1) of aerosil was incorporated in microemulsion as compare to other adsorbent. The prepared solid microemulsion was subjected to characterization for angle of repose, bulk density, tapped density, Hausner’s Ratio, Carr’s index, drug content, ex-vivo drug release study and stability studies. The solid microemulsion with aerosil 200 showed excellent free flowing property and % compressibility. From ex-vivo drug release studies, the release of darunavir from solid microemulsion (74.96±1.42 %) was found to be higher than the pure drug (47.55±2.12%). The results of the present study concluded that the solid microemulsion of Darunavir can be a promising approach to increase solubility and dissolution of the drug to increase its absorption and bioavailability for oral drug delivery.