Studies on in vitro release of cyclosporine A-loaded microspheres

环孢素A微球的体外释放影响因素(英文)

Aim This study was to prepare cyclosporine A （CyA） microspheres （Ms） using 75：25 poly （D, L-lactide-co-glycolide） polymer （PLGA）, and to evaluate the in vitro release of the CyA microspheres. Methods CyA-Ms were prepared by an oil-inwater （o/w） emulsion solvent extraction/evaporation process and characterized for drug content, particle size, surface morphology, and differential scanning calorimeter （DSC）. Accelerated in vitro release of cyclosporine A from the mieropsheres was studied at various conditions, such as temperatures, surfactants, pH values and organic solvents for a short period. Results CyA-Ms were in spherical shape with average particle size of 50 μm and loading efficiency of 13.0%. The results of DSC measurements suggested that at the dry state, CyA did interact very strongly with the hydrophilic PLGA polymer. In vitro release test in various release medium showed slight increase of CyA-Ms release profiles under various conditions of temperatures, surfactants and pH values. However, dramatical increase of CyA-Ms release was seen in the medium containing 30% isopropanol. Conclusion It was demonstrated that CyA could be incorporated into polymeric Ms prepared from PLGA using a solvent evaporation technique. The release medium containing 30% isopropanol might be the ideal condition for CyA-PLGA microspheres in vitro quality control test.

目的以环孢素A为模型药,使用生物可降解材料乳酸/羟基乙酸PLGA制备微球。并评价微球的体外释放。方法使用乳化溶剂挥发法制备环孢素微球,并对微球的外观,粒径和载药量进行评价。通过衡量温度,pH值和表面活性剂等因素筛选体外释放介质。结果制得的微球外观圆整,粒径统一,平均粒径50μm左右,载药量为13%。DSC结果表明环孢素A和PLGA有结合作用。体外释放实验表明微球的释放受温度,pH值和表面活性剂的影响,加入30%的异丙醇可使微球在2周内释放完全。结论乳化溶剂挥发法可制备得到质量符合要求的环孢素微球,含30%异丙醇的释放介质是微球体外释放评价的理想介质。