甲硝唑棒溶出度的研究

Dissolution of Metronidazole Stilus

作者用转篮法测定了治疗牙周炎的新制剂甲硝唑棒的溶出度。结果表明,本品的溶出动力学过程接近一级速度过程。K、t_(0.5)及t_(0.9)分别为6.24×10^(-2)min^(-1)、12.8及38.6min。在静置条件下。主药最初溶出很快,以后逐步减慢,48小时的累计溶出量为71.76％。故我们建议本品可每两天给药1次。

Metronidazole stilus is a new prepara-tion to be inserted into periodontal pocketsfor treatment of periodontitis.The certifi-cate and file number of approval given tothis new product were issued by the Min-istry of Public Health in August, 1989. Itsshape looks like a toothpick and the width,thickness and length are 1.5mm, 0.7mm and3 cm, respectively.The content of metroni-dazole in each cm of the stilus is 2.2 mg.We have studied the dissolution of the newpreparation by rotation basket method.The kinetic process of dissolution approxi-mates first order kinetics. The K, t_(0.5) andt_(0.9) are 0.0624min^(-1), 12. 8 and 38. 6 minutes.respectively.The requirement is that thedissolved percentage should not be lowerthan 60％ of the added amount in 30 minu-tes.In order to have a dissolution test si-milar to that of the stilus in dental pock-ets,we examined the dissolution in staticcondition.The results showed that a veryhigh dissolution rate appeared in the be-ginning, but it decreased quickly, and 71. 76％of metronidazol was not dissolved until48 hours. So one insertion per two days forclinical use is suggested.