Solubility of mesalazine in ethylene glycol plus water mixtures at different temperatures

Solubility profile for mesalazine in the mixtures of ethylene glycol and water is measured by a shake-flask method at 2932-313.2 K. Results indicated that the experimental mole fraction solubility of mesalazine in the investigated mixtures increases with increasing the mass fraction of ethylene glycol at a given temperature. Moreover, the mole fraction solubility of mesalazine shows a positive relation with temperature variations as expected. The five solubility models including van't Hoff, the mixture response surface, Jouyban-Acree, Jouyban-Acree-van't Hoff and the modified Wilson models are applied to correlate the experimental solubility data. The accuracy of the employed models is investigated by computation of the mean relative deviations (MRD%) for back-calculated data. Furthermore, apparent thermodynamic properties of standard enthalpy, Gibbs free energy and entropy of the dissolution process are calculated and discussed. Moreover, by means of inverse Kirkwood-Buff integrals, it is observed that mesalazine is preferentially solvated by water and preferentially solvated by ethylene glycol in mixtures of 024 < x(1) < 1.00. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The solubility of mesalazine in ethylene glycol-water mixtures was studied at different temperatures, showing an increase with higher ethylene glycol mass fraction. The solubility also increased with temperature variations. Five solubility models were used to correlate experimental data and investigate accuracy. Additionally, apparent thermodynamic properties were calculated and discussed. Mesalazine was observed to be preferentially solvated by water and ethylene glycol in certain mixtures.