Abstract:

In order to improve the drug loading, urea was used to insert into the montmorillonite interlayer by solid-phase grinding method. After this process, the ibuprofen was loaded by the solution blending to obtain ibuprofen/urea-montmorillonite (S(+)-IBU/urea-MMT) composite. The composites were characterized by X-ray diffraction (XRD) and Fourier transformed infrared (FT-IR) spectroscopy. The in vitro drug release behaviors of S(+)-IBU/urea-MMT were investigated by the dialysis method. Three models of in vitro drug release could be used to simulate the release performance of the S(+)-IBU/urea-MMT composites. The results show that the urea was intercalated into the montmorillonite layers, and the interlayer spacing of montmorillonite was enlarged from 1.20 to 1.79 nm. The maximum loading capacity of S(+)-IBU on the modified montmorillonite was 227.9 mg·g^-1, increased by a factor of 30%. In the artificial gastric juice (pH 1.2) and in the artificial intestinal juice (pH 6.8), the in vitro cumulative amount of the composites were 19.2% and 88.4% respectively. The variation of in vitro release rate can be well described by the zero order kinetics model.

Key words: montmorillonite, S(+)-ibuprofen, urea, sustained release, pharmaceuticals

摘要：

以蒙脱土为药物载体，利用尿素固相研磨法将蒙脱土层间距撑大，以提高其载药量；采用溶液插层法实现右旋布洛芬的有效负载，制备右旋布洛芬/尿素改性蒙脱土[S（+）-IBU/urea-MMT]复合物；借助X射线衍射（XRD）和傅里叶红外变换光谱（FT-IR）对复合物进行结构表征；采用透析法研究复合物中药物的体外释药性能；运用3种数学模型对其体外释放行为进行拟合分析，探索释药机理。结果表明，在尿素的作用下，蒙脱土的层间距由1.20 nm增大到1.79 nm，右旋布洛芬的负载量最高可达227.9 mg·g^-1，较改性前提高了30%；S（+）-IBU/urea-MMT复合物具有良好的缓释效果，在人工模拟胃液（pH 1.2）和人工模拟肠液（pH 6.8）中的累计释放量分别为19.2%和88.4%；复合物的释药行为基本符合零级释放动力学模型。

关键词: 蒙脱土, 右旋布洛芬, 尿素, 缓释, 药物