口服用硝苯地平缓释微球的研究

用丙酮/液状石蜡乳剂一溶剂挥发法制备硝苯地平一EudragitRL缓释微球。微球中药物以非晶态分散于EudragitRL载体中。微球体外释药过程符合Higuchi方程。在不同条件下存贮6个月内微球的药物含量、药物分散状态和释药速率均无明显变化。经8名健康志愿者单剂量口服实验,缓释微球相对于进口缓释片的生物利用度为102.5%,两者具有生物等价性。缓释微球的体内外相关性显著(P<0.01)。

STUDIES ON ORAL SUSTAINED-RELEASE MICROSPHERES OF NIFEDIPINE

Nifedipine has been incorporated into Eudragit RL microspheres by the emulsionsolvent-evaporation process using an acetone/ liquid paraffin system,The drug in the Eudragit RLmicrospheres was present in either molecular dispersion or amorphous state.The drug release profilefrom microspheres confoimed to the Higuchi equation,The microspheres were stable under differentstorage conditions for six months with respect to drug content,dispersing state and release profile。The in vivo results in eight healthy volunteers showed that the relative bioavailability of the nifedipinesustainecl release microspheres against commercial retard tablet as a control was 102.5%,and themicrosphere fonnulation was bioequivalent to the retard tablet.Significant in vitro and in vivocorrelation was also found for the microspheres.