左炔诺孕酮(LNG)不溶于水和紫外光照易分解的特点, 限制了其在鼠类不育剂中的应用。 该研究采用溶液法, 制备出LNG的羟丙基-β-环糊精(HP-β-CD)包合物, 建立了准确简便的紫外光谱定量检测方法; 通过相溶解度法确定了HP-β-CD与LNG的包合摩尔比为1∶1, 25 ℃时LNG-HP-β-CD包合物的稳定常数为187.3 L·mol-1; 通过紫外光谱、 傅里叶变换红外光谱表征, 验证了包合物的形成; 对包合物的抗紫外光降解性能进行了测试, 表明在50 h内包合物的降解率小于5%, 远低于药物单体。 结果表明, HP-β-CD对LNG具有良好的包合作用, 可显著提高该药物的水溶性和紫外稳定性。

The characteristics of levonorgestrel (LNG), low solubility and the quick degradation under ultraviolet, limited its study and application in rodent contraception. The inclusion complex of hydroxypropyl-β-cyclodextrin (HP-β-CD) with LNG was investigated in present study. The inclusion complex was prepared by solution method and characterized by ultraviolet absorption spectrum and infrared spectrum spectra. And the stability was evaluated by being exposed to ultraviolet. The authors’ results showed that the accurate and simple method of quantitative determination for LNG was established by ultraviolet spectrum, the molar ratio of the complex was 1∶1 calculated from the phase solubility diagram, the stability constant was 187.3 L·mol-1 at 25 ℃, and the formation of the inclusion complex was validated by UV-Vis and Fourier transform infrared spectroscopy. Moreover, the degradation rate of the inclusion complex was less than 5%, which was slower than the LNG monomer. The present study indicated that HP-β-CD could be formed inclusion complexes with LNG and the solubility, and stability were obviously enhanced.