介质对硝苯地平缓释制剂溶出行为的影响

研究硝苯地平的两种国产普通片、一种进口缓释片和自制缓释微球在不同介质中的溶出行为。结果发现，介质对硝苯地平制剂的溶出速度有很大影响。以２０％乙醇水溶液或０．５％十二烷基硫酸钠水溶液为介质，缓释片和缓释微球的溶出太快，且不能区别各制剂的溶出度差异。在０．１ｍｏｌ／Ｌ盐酸或ｐＨ６．８磷酸盐缓冲液中加入０．０２％或０．１％吐温－８０，分别作为介质，能较好评价制剂的溶出行为。在含０．０２％吐温－８０的０．１ｍｏｌ／Ｌ盐酸溶液中投入微球２、５和１０ｍｇ对溶出度无显著影响。

EFFECT OF MEDIA ON DISSOLUTION BEHAVIORS OF SUSTAINED RELEASE NIFEDIPINE FORMULATIONS

The dissolution behaviors of two conventional tablets,one retard tablet and sustained release microspheres in different media were studied by using paddle method.The dissolution rates of retard tablet and microspheres were too rapid in 20% ethanol or 0.5% sodium lauryl sulfate aqueous solution to conform with the specifications of sustained release formulations,and to indicate the dissolution difference.The 0.1 mol/L HCl or pH6.8 phosphate buffer solution containing 0.02% or 0.1% tween 80 was found to be good for in vitro dissolution evaluation of 10 or 20 mg nifedipine formulations.The effect of different amount of microspheres added into medium on dissolution profiles was not detectable until the nifedipine solubility was approached.