【摘要】 目的制备法莫替丁生物黏附型中空微球,并对其进行初步评价。方法采用溶剂-扩散挥发法制备法莫替丁生物黏附型中空微球,以微球包封率、收率及漂浮率为指标通过正交试验优化处方工艺,以优化处方制备的微球进行离体黏附性试验、体外溶出实验,并进行释药机理的探讨。结果法莫替丁生物黏附型中空微球的最优处方及工艺为:乙基纤维素质量浓度为27.0 g·L-1,法莫替丁质量浓度为4.8 g·L-1,无水乙醇与无水乙醚体积比为17∶3。最优处方下制得微球外观圆整,粒径分布较均匀,在扫描电镜下横切面可见明显中空结构,平均包封率和离体黏附率分别为82.0%和98.0%,在人工胃液中12 h漂浮率可达87.0%。12 h体外释放90%以上。结论该法所制中空微球在人工胃液中具有良好的漂浮、黏附及缓释特性,体外释药符合Higuchi模型。更多还原

【Abstract】 Objective To prepare bioadhesive hollow microspheres of famotidine and evaluate their characteristics. Methods The bioadhesive hollow microspheres of famotidine w ere prepared by the solvent diffusion-evaporation method. The floating rate formulation and process factors including the encapsulation efficiency,yield and rate of floatage w ere fully investigated using the orthogonal test to obtain the microspheres w ith good dispersion. The dissolution and adhesion experiments of the hollow microspheres prepared under the optimized conditions proceeded in vitro to analyze the mechanism of drug release behavior. Results The most superior prescription w as that the concentration of ethyl cellulose w as27. 0 g·L-1,famotidine was 4. 8 g·L-1,and the volume ratio of ethanol and ether was 17∶ 3. The prepared microspheres w ere spherical and smooth in appearance. The particle size distribution w as uniform. The hollow structure of microspheres could be obviously observed under a scanning electronic microscope. The encapsulation efficiency and adhesion percentage in vitro could reach to be 82. 0% and 98. 0%,respectively. M ore than 87. 0% of the microspheres tended to float in simulated gastric fluid for 12 h. The drug release degree in vitro of microspheres w as more than 90% in 12 hours. Conclusions This preparation method of microspheres is simple and reproducible. These microspheres show excellent floatability,adhesion,and sustained release performance. The accumulative release profile in vitro could be described by Higuchi equation.更多还原