地塞米松羧甲基魔芋胶小丸的体外释药探讨

In vitro release of dexamethasone from carboxymethyl konjac glucomannan pellets

目的:对地塞米松羧甲基魔芋胶小丸的体外释药进行探讨,评价其释药特性。方法:采用离子胶凝法制备小丸,测定其在不同释放介质(pH、离子强度和β-甘露聚糖酶浓度)条件下的药物释放、丸粒溶胀和溶蚀情况。结果:随释放介质pH、β-甘露聚糖酶浓度增加及离子强度降低,丸粒的溶胀度和溶蚀度增加,小丸释药加快;与不含酶的介质相比,小丸在含酶介质中的药物释放和丸粒溶蚀明显加快,释药数据符合Peppas方程,释药机制为酶降解溶蚀释放(释药指数n>1)。小丸在模拟胃、肠道上段的介质中,5 h累积释药15%左右,在模拟结肠部位的含酶介质中14 h累积释药达90%左右。结论:地塞米松羧甲基魔芋胶小丸体外释药与介质pH、离子强度和酶浓度有关,释药过程具有结肠定位释药特性。

Objective： To investigate in vitro release of dexamethasone（Dex） from carboxymethyl konjac glucomannan（CMKGM） pellets for elevating drug release characteristics of the pellets.Methods： The pellets were prepared by ionotropic gelation technique.The effects of pH,ionic strength orβ-mannase concentration of the dissolution media on release of Dex、swelling ratio and erosion properties of the pellets were studied.Results： With the increased of pH value,β-mannase concentration or the decreased of ionic strength of the dissolution media,the swelling ratio and erosion percent of the pellets increased,the drug release rate increased.Compared with the dissolution media without enzyme,the release of Dex and the erosion of the pellets were increased obviously in the media withβ-mannase.The release of Dex followed Peppas equation,drug release mechanism was enzymatic erosion-controlled（the n value was more than 1）.The accumulated release of drug was about 15 % within 5 h in the artificial media of stomach and small intestine,while the release reached to about 90 % in the artificial medium of colon in 14 h.Conclusion： The release of Dex from CMKGM pellets is releated to pH,ionic strength andβ-mannase concentration of the dissolution media,the pellets have the potential to be used as a new colon-specific drug delivery system.