Solubility measurement, correlation and dissolution thermodynamics properties of marbofloxacin in binary solvents

Marbofloxacin (MAB) is a broad-spectrum veterinary antibacterial drug with the great application prospects. The solid-liquid equilibrium solubility of MAB in three kinds of aqueous binary solvent systems (ethanol + water, acetonitrile + water, and methanol + water) was determined between 283.15 and 323.15 K using a dynamic laser-monitoring method at atmospheric pressure. The experimental results revealed that the solubility of MAB increased with increasing temperature and mole fraction of water in the three binary solvent systems. The modified Apelblat, kh, and (non-random two-liquid) NRTL models were used to correlate the experimental data. For the ethanol + water system, the modified Apelblat model provided a better correlation with the experimental results than the other two models. However, for the acetonitrile + water and methanol + water systems, the most favorable correlation was obtained using the NRTL model. Furthermore, the van't Hoff equation was used to study the thermodynamic properties of MAB. The obtained solubility data and thermodynamic properties of MAB can provide theoretical guidance for selecting the appropriate solvent system for the reaction, crystallization, and purification of MAB. (C) 2022 Elsevier B.V. All rights reserved.