低分子肝素/壳聚糖/海藻酸钠复合微囊的制备及释药性能

Preparation of Low Molecular Weight Heparin/Chitosan/Alginate Microcapsules and Their Drug-release Performance

以低分子肝素(LMWH)为囊芯,通过乳化分散成微囊核,然后依次用壳聚糖(CS)和海藻酸钠(ALG)通过大分子自组装形成多层结构的复合胶囊。IR和SEM测试技术对微囊进行的结构表征和形态观察表明,CS与LMWH、CS与ALG均以静电作用相结合。微囊球形规整,粒度分散性好,平均粒径为(6.9±0.85)μm。微囊对LMWH的包封率最高可达93.5%。微囊的体外药物释放实验表明,其半释放率的释放时间可长达72h。随CS浓度或ALG浓度的增大,药物释放速率减缓;释药速率随药物与壳聚糖质量比的增大而加快;交联度越高,微囊的释药速率越小;微囊在酸性条件下释药较快。

The microcapsular cores were prepared by (dispersing) low molecular weight heparin(LMWH) in emulsion, which were encapsulated with chitosan(CS) and then with (alginate)(ALG) by means of macromolecular self-assembly to form complex microcapsules with a multi-layer structure. The IR results indicated that there were strong electrostatic interactions between LMWH and CS and (between) CS and ALG. The SEM images showed the LMWH/CS/ALG microcapsules were spherical with an (average) diameter of (6.9±0.85) μm. The degree of encapsulation of the LMWH was as high as 93.5%. The (results) of the release kinetics experiments of the microcapsules show that the half-(life) of LMWH in the microcapsules reached 72 h. With the increase of the concentration of CS or ALG, the LMWH-releasing rate decreases; the higher the mass ratio of LMWH to CS, the faster the drug-release rate of the microcapsules; higher cross-linking degree results in a better drug-release performance; and the drug releases slightly faster in acid media than in alkali ones.