Study of solute-solvent intermolecular interactions and preferential solvation for mevastatin dissolution in pure and mixed binary solvents

• Research on the solubility of mevastatin in pure and mixed solvents; • Solute-solvent interactions in pure solvents were analyzed by KAT-LSER model; • The solubility parameter method and preferential solvation in mixed solvent were calculated; • The solubility profile was correlated by two thermodynamic models. The solute-solvent and solvent-solvent interactions between mevastatin and different solvents were studied. In pure solvent, the largest solubility was found in 2-butanone (2.592×10 -2 ) and minimum in cyclohexane (5.068×10 -5 ) at 318.15 K. The non-specific and hydrogen bonding interactions including the dipolarity/polarizability ( π *), Hildebrand solubility parameter ( δ H ), hydrogen bond acidity ( α ) and hydrogen bond basicity ( β ) were analyzed. In mixture of (ethyl acetate + ethanol), the maximum solubility (2.144×10 -2 ) is observed in 80%: 20% w / w of ethyl acetate : ethanol. Almost the same interaction energy and equilibrium mixing energy between solute and solvent promote the occurrence of co-solvency phenomenon. Moreover, according to the preferential solvation results, it is conjecturable that in intermediate composition mixtures and ethyl acetate-rich mixtures, mevastatin molecules are acting mainly as Lewis acid and Lewis base, respectively. Meanwhile, two thermodynamic models including modified Apelblat equation and Jouyban-Acree model are suitable to evaluate the dissolution profile, and the maximum value of relative average deviation is no more than 5%. The apparent thermodynamic properties of dissolution process in all investigated solvents are calculated which suggest that dissolution process is an endothermic process.