Solution thermodynamics and preferential solvation of hesperidin in aqueous cosolvent mixtures of ethanol, isopropanol, propylene glycol, and n-propanol

Abstract

The solubility of hesperidin in some {cosolvent (1) + water (2)} mixtures expressed in mole fraction at temperatures from 293.15 K to 333.15 K reported by Xu et al. has been used to calculate the apparent thermodynamic functions, Gibbs energy, enthalpy, and entropy, of the dissolution processes by means of the van't Hoff and Gibbs equations. Non-linear enthalpy-entropy relationships were observed for this drug in the plots of enthalpy vs. Gibbs energy of dissolution with positive or negative slopes regarding mixtures composition and/or cosolvent. Moreover, the preferential solvation of hesperidin by the cosolvents was analysed by using the inverse Kirkwood-Buff integrals observing that this drug is preferentially solvated by water in water-rich but preferentially solvated by cosolvents in mixtures 0.20 (or 0.24) ? x1° ? 1.00. Furthermore, a new mathematical model was proposed for correlating/predicting the solubility of hesperidin in binary solvent mixtures at various temperatures. © 2018 Informa UK Limited, trading as Taylor & Francis Group