【摘要】 目的以法莫替丁为模型药物,制备一种胃漂浮微丸,以延长胃内存留时间,提高药物的生物利用度。方法采用挤出滚圆法制备载药丸芯,以粉体学性质为指标进行处方筛选;采用流化床包衣的方法在载药丸芯外部包上产气层(含有碳酸氢钠的羟丙基甲基纤维素)和阻滞层(EudragitRL30D,RS30D,NE30D),并分别考察各处方微丸的漂浮性和体外释放性质。结果制得的微丸可以在5 min内起漂,持续漂浮达8 h以上,药物5 h缓释率达到93.5%。微丸的起漂时间随着产气物质[碳酸氢钠(NaHCO3)]质量的增加而缩短,随着外层阻滞层包衣增量的增加(EudragitNE30D)或Eudragit RS30D质量的增加(Eudragit RL30D/RS30D)而延长。结论试验制得的胃漂浮型微丸既能快速起漂、持续漂浮达8 h以上,又能缓慢释放药物。更多还原

【Abstract】 Objective To prepare the drug-loaded gastric floating pellets for the prolongation of the gastric residence time and to increase the oral bioavailability,taking famotidine as a model drug.Methods The drug-loaded pellets were prepared by extrusion-spheronization technique,then the pellet coating was performed by the fluid-bed method.The coating layers consisted of two layers,the inner layer was effervescent layer and the outer layer was gas-entrapped layer which protect the gas generated in inner layer and act as a control role of the release rate.The formulations of core pellets and two coating layers were investigated respectively.The micromeritic properties of core pellets,floating ability and in vitro drug release properties of the coated pellets were evaluated to optimize the formulations.Results The drug-loaded core pellets were formulated with MCC and stearic acid.The inner layer was constructed by HPMC with NaHCO3 as an effervescent agent,and the outer layer was used aqueous colloidal polymer dispersion(Eudragit RL 30D,RS 30D,NE 30D).The time of starting float shortened as the amount of effervescent agent increased and prolonged with the increase of coating amount of the outer layer.The resultant floating pellets could float within 5 minutes and maintained the buoyancy over 8 h,and the drug release rate was 93.5% over 5 h.Conclusions The floating pellets could be produced by two layers coating and the floating property and release rate can meet the design requirements.更多还原