SM-1小粒径肠溶微丸的制备及体外评价

目的制备SM-1小粒径肠溶微丸,并优化其处方,以达到肠溶和便于小动物给药的目的。方法采用流化床空白丸芯上药法,在丸芯表面依次包覆含药层、羟丙基甲纤维素（HPMC）隔离层和丙烯酸树脂（EudragitL30D-55）肠溶层。以载药量、耐酸性及释放度为指标,对SM-1肠溶微丸的处方进行优化。结果隔离层增重8%,肠溶层增重15%的肠溶微丸粒径〈450μm（40目筛）,圆整度良好,载药量约为20%;在pH为2.0的盐酸溶液中2 h内肠溶衣层薄层完好,药物释放度〈4%;在pH为6.8的PBS溶液中,45 min内释放度均〉70%。结论采用流化床制备SM-1肠溶微丸工艺可行,重现性好,具有良好的肠溶特性,粒径〈380μm,可用于小动物给药。

Preparation and in vitro evaluation of SM-1 enteric-coated pellets

Objective To prepare and optimize the formulation of SM-1 enteric coated pellets for enteric coating and convenient administration for small animals.Methods SM-1 enteric coated pellets were prepared by fluidized bed.Three separate layers,the drug layer [the barrier layer（HPMC）,and the enteric layer（Eudragit L30D-55）] were coated onto the inert core pellets.The pellets were optimized with the drug loading,acid resistance and drug release as the process parameters.Results The SM-1 enteric-coated pellets containing 8% weight gain of barrier layer and 15% weight gain of enteric layer had good appearance,the drug loading rate was about 20% and the particle size was less than 450 μm.The accumulative release of the pellets in pH 6.8 phosphate buffer solution at 45 min was more than 70%.The accumulative release in pH 2.0 hydrochloric acid at 2 h was less than 4%.Conclusion SM-1 enteric coated pellets preparation with the fluidized bed technology is feasible and replicable.The pellets show satisfactory enteric characteristics with the particle size smaller than 380 μm,suitable for small animals.