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目的:研究西洛他唑与二甲基-β-环糊精(DM-β-CD)在混合溶液中的包合作用及包合过程中的热力学参数变化。方法:在柱温为25℃,37℃,45℃时,采用反相高效液相色谱法测定西洛他唑在不同浓度的DM-β-CD混合溶液中的保留时间(retentiontime,tR),计算包合平衡常数(kf)和包合热力学参数。结果:柱温为25℃,37℃,45℃时,包合平衡常数(kf)(L/mol)分别为23.82,19.68,17.11;吉布斯自由能(ΔG)(kJ/mol)分别为-7.86,-7.68,-7.51。结论:西洛他唑与二甲基-β-环糊精可形成摩尔比(1∶1)的包合物,包合过程可自发进行(ΔG<0),且为放热反应(ΔH<0),包合过程是熵减过程(ΔS<0),在较低的温度下有利于包合物的形成,且稳定。
Objective: To study the inclusion of cilostazol and dimethyl-β-cyclodextrin (DM-β-CD) in the mixed solution and the change of thermodynamic parameters during the inclusion process. Methods: The retention time (tR) of cilostazol in different concentrations of DM-β-CD mixed solution was determined by reversed-phase high performance liquid chromatography at 25 ℃, 37 ℃ and 45 ℃. Calculate inclusion equilibrium constant (kf) and inclusion thermodynamic parameters. Results: The equilibrium constants (kf) (L / mol) of the inclusion complexes were 23.82, 19.68 and 17.11 at 25 ℃, 37 ℃ and 45 ℃ respectively. The Gibbs free energy (ΔG) (kJ / mol) -7.86, -7.68, -7.51. CONCLUSIONS: Cilostazol and dimethyl-β-cyclodextrin form inclusion complexes in a molar ratio (1: 1). The inclusion process proceeds spontaneously (ΔG <0) and is exothermic (ΔH < 0), the inclusion process is the entropy reduction process (ΔS <0), which is favorable for the formation of inclusion complex at lower temperature and is stable.