白桦脂酸缓释片的制备工艺研究

［摘要］目的制备白桦脂酸缓释片，并对其释药性质进行研究。方法分别采用不同粒度白桦脂酸不同粒度、含量的羟丙甲纤维素(HPMC)，以及不同的压片压力制备白桦脂酸缓释片，在0.5%十二烷基硫酸钠（SDS）溶液的释放递质中测定其释放度。结果HPMC的粒度和黏度、白桦脂酸粒度对本制剂的释药影响较大。随着HPMC用量的增加释药速率减慢。结论白桦脂酸缓释片的释药过程通过Peppas方程拟合，发现释放指数（n值）为0.75，初步说明白桦脂酸从骨架中的释放是扩散和溶蚀综合作用的结果，为不规则转运。影响药物释放的主要因素是白桦脂酸的粒度、HPMC的用量和粒度。

Preparation of Betunilic Acid Sustained-release Tablets and Its Release Property

Objective To prepare betulinic acid sustained-release tablets and investigate their release characteristics. Methods Different particle sizes of betunilic acid and HPMC,different viscosity grades and amount of HPMC and different pressures were used to prepare betulinic acid sustained-release tablets.The drug release was determined in 0.5%SDS solution medium. Results The HPMC particle size,viscosity grade and the particle size of betulinic acid had greater influence on drug release.Accompanying the increasing amount of HPMC,the drug release rate slowed down. Conclusion The releasing behavior of the betulinic acid sustained-release tablets in vitro through simulation of the Peppas equation,the n value of release index was found to be 0.75,indicating that the betulinic acid sustained-release tablets release by both diffusion and erosion(anomalous transport).The main factors affecting drug release are particle size of betulinic acid and HPMC,and the content of HPMC.