Solubility determination and thermodynamic models for dehydroepiandrosterone acetate in mixed solvents of (ethyl acetate + methanol), (ethyl acetate + ethanol) and (ethyl acetate + isopropanol)

Abstract

The solubility of dehydroepiandrosterone acetate in binary solvent mixtures of (ethyl acetate+methanol), (ethyl acetate+ethanol) and (ethyl acetate+isopropanol) was determined experimentally by using an isothermal dissolution equilibrium method within the temperature range from (273.15 to 313.15)K under atmosphere pressure (101.1kPa). The solubility of dehydroepiandrosterone acetate increases with increasing temperature and mass fraction of ethyl acetate in each binary system. At the same temperature and mass fraction of ethyl acetate, the solubility of dehydroepiandrosterone acetate was greater in (ethyl acetate+isopropanol) than in the other two mixed solvents. The measured solubility values were correlated with the Jouyban-Acree model, van’t Hoff-Jouyban-Acree model, and modified Apelblat-Jouyban-Acree model. The Jouyban-Acree model was proven to give better representation for the experimental solubility, which provided the lowest relative average deviation and root-mean-square deviation (0.49×10−2 and 0.97×10−4 for ethyl acetate+methanol, 0.44×10−2 and 0.82×10−4 for ethyl acetate+ethanol, and 0.92×10−2 and 3.05×10−4 for ethyl acetate+isopropanol, respectively). Based on the solubility values obtained, the standard dissolution enthalpies for the dissolution process were computed. The dissolution process of dehydroepiandrosterone acetate in these mixed solvents was endothermic. The experimental solubility and the equations presented in the present work can be employed as essential data and models in the practical process for production and purification of dehydroepiandrosterone acetate.