左旋氧氟沙星聚乳酸眼内缓释植片研制及其体外释药实验

Preparation and in vitro releasing performance of intraocular polylactide-levofloxacin sustained release implants

目的:研制左旋氧氟沙星眼内缓释植片并观察其体外缓释效果。方法:以重均分子量为50000g.moL-1的DL-聚乳酸(PDLLA)为载体,通过溶液分散法制备载药量分别为5,10,20%的PDLLA-盐酸左旋氧氟沙星眼内缓释植片。利用紫外分光光度法检测3种缓释植片30d内在体外介质中释药含量,并将释放曲线进行Higuchi模型拟合,缓释植片进行IR谱图分析比较。结果:3种缓释植片30d内累积释放量为28.6%～71.4%,在8～30d释药后期药物释放平稳且缓慢;载药量较大的缓释片,释药早期突释现象较显著。3种缓释片的体外释放曲线均能较好的符合Higuchi模型,IR谱图显示缓释片中药物分散均匀。结论:研制的聚乳酸左旋氧氟沙星眼内缓释植片在体外释药研究中表现出良好的药物缓释行为和表征,符合临床治疗时间需要。

OBJECTIVE To prepare polylactide-levofloxacin intraocular sustained release implants and investigate the performance of sustained release in vitro. METHODS Based on polylactide with the average molecular weight of 50 000 g·mol^-1 as the matrix,three kinds of polylactide-levofloxacin hydrochloride sustained release implants containing 5, 10 and 20% levofloxacin hydrochloride were fabricated by solvent evaporation. Release percent contents of these three kinds drug implants in vitro within 30 days were detected by ultraviolet spectrometry, while curves of drug release were fitted to the Higuchi model and the implants essayed comparably by IR spectrogram. RESULTS Accumulation release percent contents of these sustained release implants in 30 days range from 28. 6%-71.4%, and in the later stage（8-30 d）, all the implants exhibit stable and slow release behaviors; for the sustained release implants with higher content of levofloxacin,burst release in early stage （1-7 d） is more obvious. All of the three curves of drug release in vitro are corresponded to the Higuchi model, and the levofloxacin is evenly distributed in the sustained release implants by IR analysis. CONCLUSION The prepared polylactide-levofloxacin sustained release implants display satisfactory performance of sustained release, that complies with the requirement for clinical use.