两性霉素B聚乙二醇-磷脂酰乙醇胺胶束的制备与体外评价

Preparation and in vitro characterization of amphotericin B PEG-PE micelles

目的制备两性霉素B（amphotericin B,AmB）聚乙二醇-磷脂酰乙醇胺嵌段共聚物（polyethyleneglycol-phosphatidylethanolamine,PEG-PE）载药胶束,并进行体外评价。方法采用薄膜分散法制备AmB载药胶束,分别利用透射电镜、粒径仪和zeta电位分析仪对胶束的形态、粒径和表面电位进行表征。分别采用超速离心法、透析法和吸收光谱法考察载药胶束的载药量与包封率、体外释药行为及AmB在胶束内的聚集状态,并通过溶血试验和微量液基稀释法测定AmB胶束的溶血性及体外抗真菌活性。结果胶束粒子外观圆整且分散良好,粒径在48.28～62.02 nm内,载药量质量分数在16.7%～41.2%内,包封率质量分数在94.4%～99.8%内。胶束的体外释药具有明显缓释特征,释药速率随载药量增加而降低。载药量质量分数低于16.7%时,AmB主要以单体形式在胶束内存在;载药量质量分数高于16.7%时,AmB在胶束内的聚集程度随载药量的增加而增加。与AmB溶液剂相比,AmB胶束的溶血性明显降低,抗真菌活性略有提高。结论 AmB胶束粒径较小且分布较窄,体外缓释特征明显,并可显著降低AmB的溶血性,有望开发成为AmB的新剂型。

Objective To prepare and in vitro characterize the AmB loaded PEG-PE micelles. Methods Thin film dispersion method was applied to prepare AmB loaded PEG-PE micelles. The morphology, diameter and surface potential of the micelles were characterized by transmission electron microscopy, size and zeta poten- tial analyzer. The ultracentrifugation method, dialysis method and absorption spectroscopy method were used to determine the drug loading content and entrapment efficiency, in vitro release of AmB loaded micelles and the relative aggregation state of the encapsulated And3, respectively. The hemolytic toxicity and antifungal activity of the micelles were studied by hemolytic experiment and broth microdilution method, respectively. Results The micelle was globular-shaped, and showed particle size between 48.28 nm and 62.02 nm with narrow distribution. The drug loading content and entrapment efficiency ranged from 16.7% to 41.2% and 94.4% to 99.8%, respectively. AmB was founded to be mainly in the form of monomer in the micelles when the loading content was less than 16.7% and started to form aggregates above that value. AmB loaded micelles showed clear sustained release profile and a decrease in drug release with the increasing of loading content. AmB loaded micelles revealed much lower hemolysis and slightly higher antifungal activity than AraB solutions. Conclusions The AmB loaded rnicelles show small particle size and narrow size distribution, excellent sustained release behavior and much less hemolytic toxicity than the AmB solutions. AmB loaded PEG-PE micelles have been demonstrated to a promising alternative for current used liquid dosage form.