Solubility and dissolution thermodynamic properties of Mequindox in binary solvent mixtures

The solubility of Mequindox(MEQ) in two kinds of binary mixtures(acetone+isopropanol; N-propanol+N-butanol) with different ratio was determined by shake flask method through UV–Vis spectrophotometer over the temperature from 293.15 to 323.15 K at atmospheric pressure(p = .1 MPa). The results showed that the solubility of mequindox in binary solvent mixtures was increased with temperature raised in the investigated temperature range. In the binary-solvent of acetone and isopropanol, the data was increased as the mole fraction of acetone increased. However, the solubility of MEQ was not significantly changed in the mixed solvents of N-propanol and N-butanol with different ratio. Furthermore, thermodynamic models including the modified Apelblat equation, λh equation, GSM equation and the Jouyban-Acree model were used to correlate the experimental data. In addition, thermodynamic properties, enthalpy (△H0sol), entropy (△S0sol) and Gibbs free energy (△G0sol), were calculated and analyzed in the dissolution process. This study provides a certain theoretical basis for the isolation purification and pharmaceutical formulation design of MEQ.