Panchagnula Ramesh, Dhanikula Renu Singh, Dhanikula Anand Babu
Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, S.A.S Nagar (Punjab),160062, India.
Curr Drug Deliv. 2006 Jul;3(3):287-97. doi: 10.2174/156720106777731028.
The objective of present investigation was the characterization of chitosan films after in vivo implantation. Chitosan films were prepared at three dose loadings of paclitaxel by classical casting method. They were implanted subcutaneously in Swiss mice in the neck region and were removed at 7, 15, 21 and 30 days post implantation for characterization. In vitro release studies on explanted films were done to observe the influence of the time of implantation and loading on paclitaxel release, which were correlated with amount of paclitaxel remaining in films. Residual amount of paclitaxel remaining in explanted films decreased with increase in loading i.e. after 30 days, the % residual content of drug at 25, 20 and 15 mg loadings (per film) were 13, 20 and 45 % of the initial loading. The in vivo release of paclitaxel from films with higher loadings was higher, indicating that paclitaxel, per se, altered biodegradation of chitosan. Light microscopy and SEM studies of films removed from mice provided qualitative information on the loss of integrity and biodegradation of films with time. Further, FTIR and ATR-FTIR spectra revealed the changes in the film matrix that occur after implantation.
本研究的目的是对壳聚糖膜在体内植入后的特性进行表征。采用经典流延法制备了三种紫杉醇剂量负载的壳聚糖膜。将它们皮下植入瑞士小鼠的颈部区域，并在植入后7、15、21和30天取出进行表征。对取出的膜进行体外释放研究，以观察植入时间和负载量对紫杉醇释放的影响，并将其与膜中剩余紫杉醇的量相关联。取出的膜中紫杉醇的残留量随负载量的增加而降低，即30天后，25、20和15mg负载量（每片）的药物残留百分比分别为初始负载量的13%、20%和45%。高负载量膜中紫杉醇的体内释放量更高，表明紫杉醇本身改变了壳聚糖的生物降解。对从小鼠体内取出的膜进行光学显微镜和扫描电子显微镜研究，提供了膜完整性丧失和随时间生物降解的定性信息。此外，傅里叶变换红外光谱和衰减全反射傅里叶变换红外光谱揭示了植入后膜基质的变化。
