环孢素A眼用亚微乳含量测定及其体外释放度的考察

目的测定环孢素A眼用亚微乳的含量和体外释放度。方法采用HPLC法测定乳剂中环孢素A的含量，色谱柱为Zorbax SB-C18柱，流动相为乙腈-0．5％磷酸水溶液（75：25，V：V），检测波长为210nm，柱温为70℃。分别采用正向透析法和反向透析法进行体外释放度实验，并考察了转速对药物释放特性的影响。结果环孢素A在浓度10．0～800．0μg·ml^-1范围内呈良好的线性相关性（r=0．9999），日内和日间RSD分别为0．15％和0．72％，平均回收率为99．7％。采用反向透析法测得的药物释放速率显著高于正向透析法。且转速越快，药物释放越快。结论本含量测定方法操作简便，结果准确可靠。采用反向透析扩散法方便快捷，能较好地模拟环孢素A乳剂的释药行为。

Content Determination and in Virto Release Characteristic of Cyclosporin A Submicron Emulsion for Ocular Administration

Aim To determine cyclosporin A content and study the release behavior of cyclosporin A submicron emulsion. Methods The HPLC method was established to determine the content of cyclosporin A in the emulsion. Zorbax SB-C18 column was used as the analytical column with a temperature of 70℃. The mobile phase consisted of acetonitrile and 0.5% phosphonic acid solution at the ratio of 75： 25（v/v）. The UV detection wavelength was set at 210nm. The positive and reverse dialysis bag techniques were performed to determine the release profiles of cyclosporin A in vitro, and the effect of different rotating speed on drug release was studied. Results The linear range was from 20.0μg·ml^-1 to 1 000.0μg·ml^-1（ r =0. 999 9） and the average recovery rate was 99.7%. The RSD within-day and between-day was 0. 15% and 0. 72%, respectively. The results of release tests showed that cyclosporin A was released more rapidly by reverse dialysis technique than the positive one. The release rate increased obviously with the increase of rotating speed. Conclusion The method was simple, accurate and reliable for the determination of cyclosporin A. The reverse dialysis technique could save time and preferably simulate the release behavior of cyclosporin A emulsion.