Department of Radiation, Collage of Basic Medicine, Chongqing Medical University, Chongqing 400016, PR China.
Int J Pharm. 2011 Apr 15;408(1-2):91-6. doi: 10.1016/j.ijpharm.2011.01.055. Epub 2011 Feb 1.
Baicalin-polyvinylpyrrolidone (PVP) coprecipitate was prepared by the solvent method of solid dispersion technology to improve the dissolution rate of baicalin. The coprecipitate was characterized using differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), infrared spectrometry (IR) and dissolution testing. Furthermore, AFM·IPC-208B high-resolution atomic force microscopy (AFM) was utilized to characterize the molecular morphology of baicalin within its carrier and the interaction between baicalin and its carrier. The results of DSC and XRD indicated that baicalin resided in PVP polymers in an amorphous or molecular phase, dissolution test results demonstrated that the dissolution rate of the coprecipitate was 21.4 times that of the active pharmaceutical ingredient (API). The results of IR indicated the possibility of the formation of intermolecular hydrogen bonds. The AFM·IPC-208B findings revealed that baicalin was dispersed in PVP polymers with a molecular size of 2 nm and either wrapped or surrounded by approximately 0.4 nm of a five-membered ring of PVP arranged along the carbon chain sequentially. An intermolecular hydrogen bond was formed between the 4-OH of the glucuronide of baicalin and the O of the carbonyl group from PVP in addition to the formation of intramolecular hydrogen bonds within baicalin.
黄芩苷-聚乙烯吡咯烷酮（PVP）共沉淀物通过固溶技术的溶剂法制备，以提高黄芩苷的溶解速率。通过差示扫描量热法（DSC）、X 射线粉末衍射（XRD）、红外光谱（IR）和溶解试验对共沉淀物进行了表征。此外，利用 AFM·IPC-208B 高分辨率原子力显微镜（AFM）对黄芩苷在载体中的分子形态及其与载体之间的相互作用进行了表征。DSC 和 XRD 的结果表明，黄芩苷以无定形或分子相存在于 PVP 聚合物中，溶解试验结果表明共沉淀物的溶解速率是原料药（API）的 21.4 倍。IR 的结果表明了形成分子间氢键的可能性。AFM·IPC-208B 的结果表明，黄芩苷以分子尺寸为 2nm 的形式分散在 PVP 聚合物中，被大约 0.4nm 的 PVP 五员环包裹或包围，五员环沿碳链依次排列。除了黄芩苷内形成分子内氢键外，黄芩苷的葡萄糖醛酸基的 4-OH 与 PVP 的羰基的 O 之间还形成了分子间氢键。
