Thermodynamic models for determination of the solid-liquid equilibrium of istradefylline in ethyl acetate plus (isopropanol, tetrahydrofuran, acetone) binary solvent mixtures

In this paper, we focused on solubility and solution thermodynamics of istradefylline. Herein, we investigated the solubility and solution thermodynamics of istradefylline in binary solvent mixtures by gravimetric method. The solubility of istradefylline in (ethyl acetate + isopropanol), (ethyl acetate + tetrahydrofuran) and (ethyl acetate + acetone) was measured in the temperature range of 278.15 K-333.15 K under atmospheric pressure. In order to correlate the solubility of istradefylline, we employed the modified Apelblat equation, general cosolvency model and Jouyban-Acree model. Computational results showed that the modified Apelblat equation and general cosolvency model have low mean deviation. As calculated by van't Hoff equation, the values of thermodynamic properties such as Gibbs energy, enthalpy, and entropy proved that the dissolution process is endothermic.