Solubility of naproxen in ethyl acetate plus ethanol mixtures at several temperatures and correlation with the Jouyban-Acree model

By using the van't Hoff and Gibbs equations the thermodynamic functions Gibbs energy, enthalpy, and entropy of solution and of mixing of naproxen (NAP) in some ethyl acetate + ethanol mixtures were evaluated from solubility data determined at several temperatures. By means of enthalpy-entropy compensation analysis, a non linear Delta H-soIn degrees vs. Delta(soIn)G degrees compensation plot with negative and positive slopes was obtained if all the composition intervals are considered. Finally, the Jouyban-Acree model has been applied to correlate the drug solubilities as well as the respective thermodynamic quantities of solution in these solvent mixtures. (C) 2012 Elsevier B.V. All rights reserved.