PREPARATION AND IN-VITRO EVALUATION OF MICRO EMULSION OF ANTI-HYPERTENSIVE DRUG: VALSARTAN

Valsartan is an orally administered ACE inhibitor for the treatment of hypertension and cardiac failure, but its solubility and oral bioavailability are poor. The objective of investigation is to formulate a   microemulsion drug delivery system of valsartan using minimum surfactant concentration that could improve its solubility and oral bioavailability. Valsartan microemulsion were prepared by Phase-titration method. The composition of optimized formulation consist of Capmul MCM(Oil), Tween 20 (Surfactant),PEG 400(Co-Surfactant) and it contains 40 mg of Valsartan.Pseudo-ternary phase diagrams were plotted to check for the micro-emulsification range.  Prepared microemulsion formulations were tested for micro emulsifying properties and the resultant microemulsion were evaluated for robustness to dilution, viscosity, drug content, thermodynamic stability studies and in-vitrodissolution. The optimized microemulsion formulation further evaluated for thermodynamic stability studies, particle size distribution, and zeta potential to confirm the stability of the formed Microemulsion. Resultant microemulsion optimized formulation (F2) shows drug release (99.71%), droplet size (36 nm), viscosity (0. 8872 cP), Zetapotenial (-38.8 mV) and infinite dilution capability.  The formulation was found to show a significant improvement in terms of the drug release with complete release of drug within 80 minutes. Thus, micro emulsifying formulation of valsartan was successfully developed with sustained release.