存储混合型缓释体系动力学模型

本文针对目前存储混合型缓释体系的释放动力学模型假设多、预测精度低等问题 ,探讨该体系的释放机理 ,并建立动力学模型以期为实际剂型研制提供理论依据。通过将化学工程的传递原理应用于药物控制释放领域 ,分析了药物在膜内的扩散过程 ,建立了非稳态条件下当药物初始装填量大于其在聚合物膜内饱和溶解度时的存储混合型缓释体系的释放动力学模型 ,并采用巯嘌呤和乙烯 /乙烯醇共聚物 (摩尔比为 :乙烯 /乙烯醇 =44 / 5 6 )组成的存储混合型缓释体系对模型进行实验验证。实验结果表明 ,模型的预测值与实验值吻合较好 (相对偏差 <5 % )。同时讨论了药物初始装填量、空白膜厚等因素对释放速率的影响。

A KINETIC MODEL FOR DIFFUSION-CONTROLLED RESERVOIR-MONOLITHIC SYSTEM

Because the current models of reservoir-monolithic system can not elaborate the release mechanism well, the purpose of this work is to developa more practical and accurate model. The theories of chemical engineering were applied to controlled release of the drug, and a unsteady-state delivery kinetic model for diffusion-controlled reservoir-monolithic system (C d>C s) proposed through analyzing the diffusion process in matrix. The model was proved to be correct by the release experiment of reservoir-monolithic system composed of mercaptopurinum/ethylene-vinyl alcohol copolymer (mole ratio: ethylene/vinyl alcohol=44/56). It showed that the model predictions were in good agreement with the experimental data. In addition, some influencial factors such as drug loading and the thickness of outer membrane were discussed theoretically.