Solubility of Caffeine in N-Methyl-2-Pyrrolidone + Ethanol Mixture at Different Temperatures Publisher



Rezaei H^{1, 2} ; Rahimpour E^{2, 3} ; Ghafourian T⁴ ; Martinez F⁵ ; Barzegarjalali M⁶ ; Jouyban A^{2, 7}
Source: Journal of Molecular Liquids Published:2020

Abstract

The solubility profile of caffeine in the binary non-aqueous mixtures of N-methyl-2-pyrrolidone (NMP) and ethanol at different temperatures is determined and the obtained data are fitted to some linear and non-linear cosolvency models including the van't Hoff, the double log-log, the mixture response surface, Yalkowsky, Jouyban-Acree, Jouyban-Acree-van't Hoff, and the modified Wilson models. The measured density data of caffeine saturated solutions as another physico-chemical property are also correlated with the Jouyban-Acree model and the results are discussed. In order to investigate the accuracy of the applied models, the mean relative deviations (MRD%) of the back-calculated solubility data is calculated. Furthermore, the apparent thermodynamic properties of caffeine dissolution process are also calculated by using van't Hoff and Gibbs equations. © 2019 Elsevier B.V.