Frenning Göran
Department of Pharmacy, Uppsala University, P.O. Box 580, SE-751 23, Uppsala, Sweden.
J Control Release. 2003 Oct 30;92(3):331-9. doi: 10.1016/s0168-3659(03)00338-9.
Drug release from planar matrix systems has been investigated with special emphasis on the influence of a finite dissolution rate on the drug release profile. A mathematical model of the drug dissolution and release processes was formulated in terms of two coupled nonlinear partial differential equations (PDEs). These were solved numerically by using well-established FORTRAN routines. An approximate analytical solution, valid during the early stages of the release process, was derived. The analytical solution was compared to the numerical one and to drug release models existing in the literature. From this comparison, it was established that the analytical approximation provided a good description of the major part of the release profile, irrespective of the dissolution rate. Existing literature models, based on instantaneous dissolution, were found to agree with the numerical solution only when drug dissolution proceeded very rapidly in comparison with the diffusion process. Consequently, the new analytical short-time approximation of the drug release complements the formulas existing in the literature, since it provides a superior description of the release of slowly dissolving drugs.
人们对平面基质系统中的药物释放进行了研究，特别强调了有限溶解速率对药物释放曲线的影响。根据两个耦合的非线性偏微分方程（PDE）建立了药物溶解和释放过程的数学模型。使用成熟的FORTRAN程序对这些方程进行了数值求解。推导了在释放过程早期有效的近似解析解。将解析解与数值解以及文献中现有的药物释放模型进行了比较。通过这种比较发现，无论溶解速率如何，解析近似都能很好地描述释放曲线的主要部分。发现基于瞬时溶解的现有文献模型仅在药物溶解与扩散过程相比非常迅速时才与数值解一致。因此，新的药物释放解析短时近似补充了文献中现有的公式，因为它能更好地描述缓慢溶解药物的释放。
