The aim of this study was to developing a new formulation for quercetin that is an antioxidant drug with very poor water solubility [1]. For this goal, pseudo ternary phase diagrams were constructed to obtain microemulsion areas which had mono-phasic nature and very good thermodynamic stability [2]. Between microemulsion regions, some formulations composed of clear amounts of surfactant, cosurfactant, oil and water were chosen. Then quercetin was incorporated in w/o microemulsions, and solubility of drug was probed in each formulation. Results showed that inclusion of quercetin into w/o microemulsions caused to very good increment in drug solubility values (in comparison to its solubility in water). These outcomes were very practical in drug delivery applications of quercetin.
