Siepmann J, Ainaoui A, Vergnaud J M, Bodmeier R
College of Pharmacy, Freie Universität Berlin, Kelchstrasse 31, 12169 Berlin, Germany and Faculty of Sciences, University of Saint-Etienne, France.
J Pharm Sci. 1998 Jul;87(7):827-32. doi: 10.1021/js980006a.
The release kinetics of a polymeric-controlled release device are determined by its geometry and dimensions. A method to calculate the required size and shape of diffusion-controlled dosage forms to achieve a particular release profile is presented. The diffusion parameters are determined for various drugs (theophylline, diltiazem hydrochloride and caffeine) with thin ethyl cellulose (EC) films, containing different plasticizers [dibutyl sebacate (DBS) and acetyl tributyl citrate (ATBC)]. Computer simulations are then used to predict the drug release kinetics from various dosage forms (e.g. microparticles and cylinders). The practical benefit of these simulations is to optimize the geometry and dimensions of a controlled release device without the need of experimental studies. To verify the theoretical predictions, the release kinetics of theophylline from EC/ATBC microparticles of different size have also been determined experimentally. Good agreement is found between theory and experiment, proving the validity of the presented method.
聚合物控释装置的释放动力学由其几何形状和尺寸决定。本文提出了一种计算扩散控制剂型达到特定释放曲线所需尺寸和形状的方法。使用含有不同增塑剂[癸二酸二丁酯（DBS）和柠檬酸乙酰三丁酯（ATBC）]的乙基纤维素（EC）薄膜，测定了多种药物（茶碱、盐酸地尔硫卓和咖啡因）的扩散参数。然后利用计算机模拟预测各种剂型（如微粒和圆柱体）的药物释放动力学。这些模拟的实际好处是无需进行实验研究即可优化控释装置的几何形状和尺寸。为了验证理论预测，还通过实验测定了不同尺寸的EC/ATBC微粒中茶碱的释放动力学。理论与实验结果吻合良好，证明了所提方法的有效性。
