Dissolution thermodynamic study of naproxen in the mixtures of ethylene glycol and water

Abstract The equilibrium solubility of a weakly water-soluble drug of naproxen (NAP) in ethylene glycol (EG) + water is determined by a shake-flask method in the temperature range of 293.2–313.2 K. Five models including Jouyban-Acree, Jouyban-Acree-van't Hoff, the mixture response surface, van't Hoff and the modified Wilson models were applied to mathematical modeling of the solubility data. The mean relative deviations (MRD%) is applied for the accuracy investigation of each model. Moreover, the Jouyban-Acree model is used to a numeric representation of the density of saturated mixtures at different temperatures. The respective apparent thermodynamic quantities of the dissolution and solvation processes, namely Gibbs energy, enthalpy, and entropy, are also calculated based on the van't Hoff and Gibbs equations. Further, preferential solvation parameters of NAP by EG molecules were estimated based on the inverse Kirkwood-Buff integrals.