5-氟尿嘧啶结肠定位释药微丸的研制及释药特性

Preparation and in vitro Evaluation of Colon Specific Drug Delivery Systemof 5-Fluorouracil

采用流化床喷雾包衣法,研制了2种5-氟尿嘧啶结肠定位释药微丸。以羟丙甲纤维素为溶胀层,乙基纤维素水分散体为控制层,制备时间依赖型包衣微丸;另以肠溶型丙烯酸树脂Eudragit S100为包衣材料,制备pH依赖型微丸。测定了2种微丸在模拟胃肠道各区段pH环境下的释放度。结果表明,时间依赖型包衣微丸体外持续、缓慢释放;pH依赖型包衣微丸在模拟胃和小肠中上部pH的介质中基本不释药,在模拟回盲部区段pH介质中脉冲释药,即后者在体外显示出较好的结肠定位释药特性。

Two kinds of 5-fluorouracil (5-FU) pellets were prepared and their release profiles were studied. Onthe basis of a drug-layered pellets, the time-dependent pellets were prepared by coating with an inner layer of hydroxypropyl-methylcellulose and an outer layer of a hydrophobic film of ethylcellulose. The pH-dependent pellets were prepared bycoating with a layer of a pH-dependent polymer Eudragit S100. The time-dependent pellets showed a sustained drug releaseof 5-FU. The pH-dependent pellets demonstrated little release for 2h in pH 1.2 media and another 2h in pH 6.8 media, thena pulsed-release in pH 7.5 phosphate buffer solution. The results showed the potential of the pH-dependent pellets for colonspecific delivery of 5-FU.