复方甲硝唑根管消毒控释系统的研制及体外释放度测定

目的　制备复方甲硝唑根管消毒控释系统(CDGMC)并观察其体外释药时间。方法　利用渗透泵原理,以牙胶尖为载体,选用复方药物制成药尖,外包控释膜制备成复方甲硝唑根管消毒控释系统。根据体外释放试验提取药物释放参数,筛选出最佳制剂配方。将单根管离体牙作常规根管预备,分别置入筛选出的CDGMC,以空白控释制剂作对照,以pH 7.4温度37℃生理盐水作为释放介质,定时取样,测定吸光度,求得药物浓度,换算出释放百分率和累积释药百分率。结果　释放有效药物浓度时间最长的一组控释制剂中甲硝唑含量为1 880μg,环丙沙星为267μg。离体牙根周释药实验表明,第10天时根周环境的甲硝唑释药量为88·54μg/ml、环丙沙星为9·05μg/ ml。结论　CDGMC能持续释放有效药物浓度达10 d以上,是一种理想的根管消毒药物使用方法。

The Development and in vitro Release Rate Determination of Controlled-release Delivery Gutta-percha Point Containing Metronidazole Compound

OBJECTIVE: To prepare the controlled-release delivery gutta-percha points containing metronidazole compound (CDGMC) and to determine its release rate in vitro. METHODS: The drug points were made by using compound drugs and gutta-percha as a carrier, and CDGMC were prepared followed by enveloping a release membrane outward. The best formula was selected according to the release parameters of the drugs extracted in the release experiments in vitro. The CDGMC were placed into the extracted teeth after root canals were routinely prepared. The non-drug CDGMC was used as the control. The absorbency of the drugs in normal saline (37 degrees C, pH 7.4) was determined timely. The percentage of release and cumulated release of the drugs were calculated according to the concentrations of drugs in medium. RESULTS: The in vitro experiments showed that this system contained 1,880 micrograms of metronidazole and 267 micrograms of ciprofloxacin. The experiments in healthy single root canal showed that the drug release amounts around the perioapical area were metronidazole 88.54 micrograms/ml and ciprofloxacin 9.05 micrograms/ml in 10 days. CONCLUSION: CDGMC can continuously release effective drug concentrations more than 10 days and could be considered as an ideal method for clinical application.