Majumdar S, Roy S, Ghosh B
Calcutta Institute of Pharmaceutical Technology and Allied Health Sciences, Department of Pharmaceutics, Banitabla, Uluberia, Howrah, India.
Pharmazie. 2011 Nov;66(11):843-8.
The aim of the present study was to prepare a colon targeted pellet formulation of secnidazole and to evaluate the formulation in vitro and in vivo by a gamma scintigraphy method. Pectin/ethyl cellulose in different ratios and in different coating labels with plasticizer was used to prepare secnidazole pellets by a powder layering technique. The formulations were tagged with 99mTC-DTPA, a tracer in gamma scintigraphy to evaluate its transit behavior in rabbits. Morphology and compatibility were studied using Scanning Electron Microscopy, IR spectroscopy and Differential Scanning Calorimetry were used for the characterization of prepared pellets. The in-vitro study suggested that pectin (59%) esterification and ethyl cellulose 45cps at 20% coating label led to an optimum bacterial enzyme dependent released behavior. The optimized formulation was subjected to an in-vivo transit study. Scintigraphy images clearly indicated that the formulation can delay the drug release prior to the colon. The average time of gastric emptying and colon arrival was 57 min and 6.08 h, respectively. The coated pellets prepared by powder layering technology successfully released drug in the colon indicating that site specificity has been achieved with pectin 59% esterification and ethyl cellulose 45 cps at 1:2 ratio with 20% coating label.
本研究的目的是制备塞克硝唑结肠靶向微丸制剂,并通过γ闪烁扫描法对该制剂进行体外和体内评价。采用粉末层积技术,使用不同比例的果胶/乙基纤维素以及添加增塑剂的不同包衣标签来制备塞克硝唑微丸。制剂用γ闪烁扫描中的示踪剂99mTC-DTPA进行标记,以评估其在兔体内的转运行为。使用扫描电子显微镜研究形态和相容性,用红外光谱和差示扫描量热法对制备的微丸进行表征。体外研究表明,果胶(59%)酯化度和20%包衣标签下的45cps乙基纤维素导致了最佳的细菌酶依赖性释放行为。对优化后的制剂进行体内转运研究。闪烁扫描图像清楚地表明该制剂可在结肠之前延迟药物释放。胃排空和到达结肠的平均时间分别为57分钟和6.08小时。通过粉末层积技术制备的包衣微丸在结肠中成功释放药物,表明采用59%酯化度的果胶和45cps的乙基纤维素,以1:2比例和20%包衣标签实现了部位特异性。