交联糊精-碘微球的制备及体外释放

Preparation and in vitro release pattern of iodine cross-linked dextrin microspheres

目的用空白交联糊精微球作为载体制备交联糊精-碘微球,作为敷料用于慢性有渗出物伤口的治疗。方法使用吸附载药法,考察母液中乙醇含量、碘溶液浓度、微球吸水度对交联糊精-碘微球载药量和包封率的影响,以蒸馏水、生理盐水和模拟渗出液为释放介质,考察微球的体外释放,并对释放曲线进行方程拟合,预测释放机制。结果与结论在载药过程中,随着母液中乙醇含量的提高,载药量和包封率降低;乙醇含量一定的溶液中,碘浓度变大载药量提高,而包封率变化不大;吸水度高的微球载药量和包封率较吸水度低的微球高。交联糊精-碘微球体外释放符合Pep-pas方程(n=0.43),游离碘通过F ick扩散机制释放。在生理盐水和模拟渗出液中碘的释放进一步减缓,为交联糊精-碘微球作为敷料用于渗出性伤口的治疗时达到缓释作用奠定基础。

Objective To prepare iodine microspheres with blank cross-linked dextrin rnicrospheres, which could be used as dressing for chronic wounds with exudation. Methods Adsorbing method was employed to load drug. Then the influences of the content of alcohol, iodine in stock solution, water absorption rate of microsphers on drug-loading rate and entrapment rate were studied. In vitro release was carded out in distilled water, normal saline and simulating exudates, respectively. Higuchi equation and Peppas equation were used to simulate the in vitro release profiles, and to explain the mechanism. Results and Conclusion In drug-loading procedure, drug-loading rate and entrapment rate decreased when proportion of ethanol was increased; when ethanol content was invariable, the drug-loading rate would increase while entrapment rate retained in higher concentration of iodine. Compared to microspheres with low water absorbing rate, the batches with high water absorption rate had higher drug-loading rate and entrapment rate. The release pattern of iodine cross-linked dextrin microspheres consisted with Peppas equation （ n = 0. 43 ）, indicating that iodine release followed Fick＇s diffusion mechanism. In normal saline and simulating exudate, the release of iodine became slower than that in distilled water, which demonstrated that when the system was used in wounds with exudation, delayed release would be exhibited.