伊曲茶碱在两种混合溶剂中的固液相平衡

Solid-liquid phase equilibrium of istradefylline in two mixed solvents

伊曲茶碱是一种口服有效的抗帕金森药物,通过固液相平衡实验为伊曲茶碱结晶动力学的研究及结晶工艺的设计、优化提供参考数据。采用动态法,在283.15—323.15 K、常压下,测定了伊曲茶碱在2种二元混合溶剂(乙醇+乙酸乙酯、甲基乙基酮)中的溶解度;用Apelblat方程、λh方程对溶解度数据进行拟合;通过Van′t Hoff方程计算2种溶剂体系的溶解熵、溶解焓以及吉布斯自由能。结果表明:伊曲茶碱的溶解度与温度以及乙醇的摩尔分数有关。伊曲茶碱在不同摩尔分数混合溶剂中的溶解度随着温度的升高而逐渐增加;同一温度下,其在所处的溶剂体系中的溶解度随着乙醇摩尔分数的增加而减小。Apelblat方程关联结果优于λh方程,能更好地拟合溶解度数据。伊曲茶碱溶解过程是吸热的,熵增的,溶解焓是溶解过程中溶解吉布斯自由能的主要贡献者。

Istradefylline is an effective oral anti-Parkinson drug.Solid-liquid equilibrium experiments were carried out to provide reference data for the study of crystallization kinetics and the design and optimization of crystallizati-on process of istradefylline.Using the dynamic method,the solubility of the istradefylline was measured in two binary solvents(ethanol and ethyl acetate,ethanol and 2-butanone)at 283.15-323.15 K and atmospheric pressure.The solubility data were fitted with the Apelblat equation andλh equation.The solubility entropy,solubility enthalpy,and Gibbs free energy of the two solvent systems were calculated by Van′t Hoff equation.The results show that the solubility of istradefylline is dependent on the temperature and the molar fraction of ethanol.The solubility of istradefylline in different molar fractions of mixed solvents gradually increases with the increase of temperature.At the same temperature,its solubility in the solvent system decreases with the increase of the molar fraction of ethanol.The correlation result of Apelblat equation is better than that ofλh equation,which can better fit the solubility data.The dissolution process of istradefylline is heat-absorbing and entropy-increasing.The dissolution enthalpy is the main contributor to the Gibbs free energy of dissolution.