Solubility profile of phenytoin in the mixture of 1-propanol and water at different temperatures

Abstract

The aims of the current study are solubility behavior investigation of phenytoin in the mixtures of 1-propanol and water at different temperatures and correlation of the generated data to some linear and non-linear cosolvency models. As another physico-chemical property, the density of phenytoin saturated solutions is also measured and the results are mathematically represented using the Jouyban-Acree model. The accuracy of applied models is checked by the computation of the mean relative deviations (MRD %). Moreover, the apparent thermodynamic properties of the phenytoin dissolution process are also calculated according to van't Hoff and Gibbs equations. It is observed that all the thermodynamic quantities, namely Gibbs energy, enthalpy and entropy changes, are positive in every solvent system. Furthermore, by means of the inverse Kirkwood-Buff integrals it is shown that phenytoin is preferentially solvated by water molecules in water-rich mixtures and preferentially solvated by 1-propanol molecules in the composition interval 0.19 <x1 < 1.0.