Ternary phase diagrams and solvate transformation thermodynamics of omeprazole sodium in different solvent mixtures

• Published in: Chinese journal of chemical engineering Vol. 27; no. 2; pp. 362 - 368
• Main Authors: Jin, Meitang, Xu, Zhao, Bao, Ying, Li, Long, Wang, Liping, Lu, Haijiao, Xie, Chuang, Hao, Hongxun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2019; Collaborative Innovation Centre of Chemical Science and Engineering, Tianjin 300072, China; School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
• Subjects: Chemical reaction; Omeprazole sodium; Phase equilibria; Solvate; Ternary phase diagram; Thermodynamics; Omeprazole sodium; Phase equilibria; Thermodynamics; Solvate; Chemical reaction; Ternary phase diagram
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/j.cjche.2018.07.016

Omeprazole sodium (OMS), a typical non-hydrogen bond donors API, is only available in solvates so far, including monohydrate, ethanol solvate and methanol solvate. The methanol solvate was found for the first time. Solvate transformation thermodynamics of OMS was studied in this paper. First, the ternary phase diagrams forming two solvates for OMS in binary solvent mixtures including methanol + water, ethanol + water, and methanol + ethanol were measured at temperature ranging of T = (278.15 to 313.15) K under atmospheric pressure. Further, the standard equilibrium constants of the solvate transformation reactions were evaluated according to the chemical reaction isothermal equation. The standard molar Gibbs free energy, the standard molar enthalpy, and the standard molar entropy of solvate transformation reactions were then calculated based on van't Hoff equation. Moreover, the thermodynamic stability of the OMS solvate was analyzed based on phase diagram. The results are of great importance to develop a crystallization process for manufacturing OMS solvate, and could be helpful to other solvate transformation research.