Fu J C, Hagemeir C, Moyer D L
J Biomed Mater Res. 1976 Sep;10(5):743-58. doi: 10.1002/jbm.820100507.
The derivation and experimental verification of a unified mathematical model for the estimation of drug release rate from drug-polymer composite tablets are presented. Cylindrical coordinates are utilized in the solution of the diffusion equation for a three-dimensional system. The model is applicable to tablets that range from the shape of a flat disk (radius greater than thickness) to that of a cylindrical rod (radius less than thickness). The general solution for the fraction of drug released at a time t is (see article). This approach to a three-dimensional system, utilizing cylindrical coordinates, presents a comprehensive method for the estimation of drug release rates from sustained release tablets with drug distributed homogeneously throughout a polymer matrix. The calculated and experimental drug diffusion rate of pyrimethamine from pyrimethamine-silicone rubber composite tablets that range in shape from that of a disk to a cylinder, and of hydrocortisone from EVA, polycaprolactone, and PVA terpolymer, are compared.
本文介绍了一种用于估算药物-聚合物复合片剂药物释放速率的统一数学模型的推导及实验验证。在求解三维系统的扩散方程时采用了圆柱坐标系。该模型适用于从扁平圆盘形状（半径大于厚度）到圆柱形棒状（半径小于厚度）的片剂。在时间t时药物释放分数的通解见文章。这种利用圆柱坐标系处理三维系统的方法，为估算药物均匀分布于聚合物基质中的缓释片剂的药物释放速率提供了一种全面的方法。比较了从圆盘到圆柱形状的乙胺嘧啶-硅橡胶复合片剂中乙胺嘧啶以及从乙烯-醋酸乙烯共聚物、聚己内酯和聚乙烯醇三元共聚物中氢化可的松的计算和实验药物扩散速率。
