Zhang J X, Zhu K J, Chen D
Zhejiang University, Hanzhou, PR China.
J Microencapsul. 2005 Mar;22(2):117-26. doi: 10.1080/02652040400026335.
BSA-loaded mcirospheres were prepared by a modified phase separation method, in which petroleum ether (PE) containing a certain amount of Span 80 rather than poly (dimethylsiloxane) (PDMS) was adopted as coacervating agent. Process parameters such as Span 80 concentration, the volume and addition rate of coacervating agent, polymer concentration, agitation rate during the phase separation process and PE type were evaluated to optimize the protein encapsulation. It was found microspheres with high yield (>80.0%) and entrapment efficiency (>90%) could be obtained using PE containing 5.0% Span 80 as the coacervating agent. Microspheres with small particle size (<10 microm) could be produced successfully with appropriate process parameters. In vitro release study suggested that burst release was significantly influenced by Span 80 concentration, polymer concentration and PE type and the burst release could be reduced to <20% with optimized formulation. A biphasic release behavior in vitro test was observed for the microspheres prepared by this method. GC analysis demonstrated that residual solvent of DCM and petroleum ether was decreased dramatically in comparison with PDMS used as a conventional coacervating agent.
通过改进的相分离法制备了负载牛血清白蛋白（BSA）的微球，其中采用含有一定量司盘80（Span 80）而非聚二甲基硅氧烷（PDMS）的石油醚（PE）作为凝聚剂。对司盘80浓度、凝聚剂的体积和添加速率、聚合物浓度、相分离过程中的搅拌速率以及PE类型等工艺参数进行了评估，以优化蛋白质包封率。结果发现，以含有5.0%司盘80的PE作为凝聚剂，可以获得高产率（>80.0%）和高包封率（>90%）的微球。通过适当的工艺参数可以成功制备出小粒径（<10微米）的微球。体外释放研究表明，突释受司盘80浓度、聚合物浓度和PE类型的显著影响，通过优化配方，突释率可降低至<20%。观察到用该方法制备的微球在体外试验中呈现双相释放行为。气相色谱分析表明，与用作传统凝聚剂的PDMS相比，二氯甲烷（DCM）和石油醚的残留溶剂显著减少。
