Dressman J B, Fleisher D
J Pharm Sci. 1986 Feb;75(2):109-16. doi: 10.1002/jps.2600750202.
A mixing-tank model is used to simulate GI absorption of nonionized drugs. The model is useful for predicting circumstances under which dissolution rate dominates membrane transport and transit rate, thus limiting the extent of absorption. The model is developed from mass balance considerations in which the nonsink dissolution term is a function of the remaining surface area and the concentration gradient across the boundary layer. Other dissolution parameters include initial particle radius, dose, diffusivity, density, and boundary-layer thickness. Readily calculable estimators for the general solution of the model are derived and their ranges of usefulness are discussed. Drug examples chosen for simulation are griseofulvin and digoxin. The model correctly predicts bioavailability as a function of particle size for both of these poorly soluble drugs.
混合槽模型用于模拟非离子化药物的胃肠道吸收。该模型有助于预测溶出速率主导膜转运和通过速率从而限制吸收程度的情况。该模型是基于质量平衡考虑而开发的，其中非漏槽溶出项是剩余表面积和跨边界层浓度梯度的函数。其他溶出参数包括初始颗粒半径、剂量、扩散系数、密度和边界层厚度。推导了该模型通解的易于计算的估计量，并讨论了它们的适用范围。选择用于模拟的药物实例是灰黄霉素和地高辛。该模型正确地预测了这两种难溶性药物的生物利用度与粒径的函数关系。
