Thermodynamic analysis and correlation of solid-liquid equilibrium of hyodeoxycholic acid in ethanol + (acetone, ethyl acetate) binary solvent mixtures

Abstract Data on corresponding solid-liquid equilibrium of hyodeoxycholic acid (HDCA) are essential for a preliminary study of industrial applications. In this paper, we focused on solubility and solution thermodynamics of HDCA. By gravimetric method, the solubility of HDCA was measured in ethanol + (acetone, ethyl acetate) binary solvent mixtures from 278.15 K to 328.15 K under atmospheric pressure. The data of equilibrium solubility were then fitted using modified Apelblat equation, a variant of the combined nearly ideal binary solvent/Redich-Kister (CNIBS/R-K) model and Jouyban-Acree model. In addition, the thermodynamic properties of the solution process, including the Gibbs energy, enthalpy, and entropy, were calculated by the van't Hoff analysis.