黄芩苷-Eudragit L100-55肠溶固体分散体制备及其体外释放度评价

Evaluation on preparation process of baicalin-Eudragit L100-55 enteric coated solid dispersion and its in vitro release

目的拟制备黄芩苷-Eudragit L100-55肠溶固体分散体,考察黄芩苷肠溶制剂的可行性。方法采用溶剂蒸发法制备黄芩苷-Eudragit L100-55(EL)肠溶固体分散体,运用差示扫描量热法(DSC)、扫描电镜法(SEM)、X射线粉末衍射法(XRD)和傅里叶变换红外光谱(FTIR)等分析方法对其微观结构和理化性质进行了分析,并对其体外释放性能进行考察。结果 DSC和XRD分析结果显示黄芩苷以无定形形式分散在固体分散体中,FTIR结果表明黄芩苷与EL之间存在非共价键作用。体外释放度测定结果表明,黄芩苷-EL比例达到1∶6时所制备的固体分散体,黄芩苷在pH 1.2的稀盐酸溶液中2 h的释放量小于3%,在pH 6.8的磷酸缓冲液中,2 h累积溶出度达到90%以上。结论所制备的肠溶固体分散体能够达到黄芩苷在人工肠液中的快速释放和增加局部药物浓度的目的,从而改善黄芩苷的口服吸收。

Objective To prepare the baicalin-Eudragit L100-55 （EL） enteric coated solid dispersion and to investigate the feasibility of this baicalin preparation. Methods Baicalin-EL enteric coated solid dispersion was prepared by using solvent evaporation method. The microscopic strucutre and physicochemical properties of solid dispersion were analyzed using differential scanning calorimetry （DSC）, scanning electron microscopy （SEM）, X-ray powder diffraction （XRD）, and infrared vibrational spectra （IR）. And its in vitro release was also investigated. Results DSC and XRD analyses suggested that baicalin may be present in enteric coated solid dispersion as amorphous substance. IR results indicated the presence of interactions between baicalin and EL. The in vitro release showed the accumulated dissolution rate of baicalin was less than 3% in artificial pH 1.2 dilute hydrochloric acid solution for 2 h, but an accumulated dissolution rate exceeding 90% in pH 6.8 phosphate buffer solution for 2 h when baicalin-EL ratio reached 1 ： 6. Conclusion Baicalin-EL enteric coated solid dispersion prepared could release drug rapidly and increase local drug concentration and then improve the oral absorption ofbaicalin.