载有胰岛素的可生物降解微球的制备与表征

用乙交酯与丙交酯的无规共聚物(PLGA)和聚乙二醇单甲醚-聚丙交酯两嵌段共聚物(MPEG-PLA)的合金作为囊材料,包裹胰岛素固体粉末,包裹率分析表明,固体粉末法对胰岛素的包裹率高于双乳液法.所得微球球形很好,尺寸在1～3μm范围,剖面具有核壳结构,胰岛素以晶粒的形式包裹在高分子壳层中.两种高分子在凝聚过程中发生相分离,在壳层中有分层现象.测定微球的体外释放行为,由聚合物合金制备的微球的暴释现象得到了缓解,两种聚合物的配比不同,其暴释缓解的程度也不一样.

Preparation and Characterization of Biodegradable Insulin-loaded Microspheres

Insulin-loaded microspheres were prepared by solid-in-oil-in-water(S/O/W) technique with a polymer alloy of poly(lactic acid-co-glycolic acid)(PLGA) and monomethoxy polyethylene glycol-b-polylactic acid(MPEG-PLA) as the carrier material. It was demonstrated that the microspheres prepared by the S/O/W technique contain more insulin than those prepared by water-in-oil-in-water(W/O/W). They had a spherical shape. Their mean size was in the range of 1-3 μm. Their cross-section had a core-shell structure and the insulin located in the core of the capsule as a crystal solid. The shell itself was layered due to the phase-separation of the polymer alloy during the course of solvent evaporation. The in vitro release behavior of the insulin mirospheres prepared by S/O/W and by W/O/W were compared. It was found that less initial burst release of insulin from the mirospheres prepared by S/O/W was observed than the other. This improvement in initial burst release was dependent on the ratio of the two components of the polymer alloy.