Veith Susanne R, Hughes Eric, Pratsinis Sotiris E
Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstr. 3, ML F25, 8092 Zurich, Switzerland.
J Control Release. 2004 Sep 30;99(2):315-27. doi: 10.1016/j.jconrel.2004.07.013.
The aim of the current study is to predict the release kinetics of organic molecules entrapped in sol-gel-made silica particles using both pulsed field gradient-nuclear magnetic resonance (PFG-NMR) techniques and model calculations to describe restricted diffusion. The macroscopic release profile of aroma molecules from sol-gel-made particles is measured directly by UV-VIS spectroscopy, while the release kinetics are calculated by the Crank equation. The microscopic restricted pore diffusion coefficient of the aroma molecules in the Crank equation is obtained in situ by pulsed field gradient (PFG) magic angle spinning (MAS) nuclear magnetic resonance (NMR). Furthermore, restricted pore diffusion coefficients obtained by model calculations are in agreement with those measured by PFG-MAS-NMR, indicating the potential of the latter for characterization and screening of encapsulation formulations. Measured and calculated release profiles agree within experimental error.
本研究的目的是利用脉冲场梯度核磁共振（PFG-NMR）技术和模型计算来描述受限扩散，从而预测包裹在溶胶-凝胶法制备的二氧化硅颗粒中的有机分子的释放动力学。通过紫外-可见光谱法直接测量溶胶-凝胶法制备的颗粒中香气分子的宏观释放曲线，同时用克兰克方程计算释放动力学。通过脉冲场梯度（PFG）魔角旋转（MAS）核磁共振（NMR）原位获得克兰克方程中香气分子的微观受限孔隙扩散系数。此外，通过模型计算得到的受限孔隙扩散系数与通过PFG-MAS-NMR测量得到的结果一致，这表明PFG-MAS-NMR在表征和筛选包封制剂方面具有潜力。测量和计算得到的释放曲线在实验误差范围内相符。
