Two-Scale, Three-Phase Theory for Swelling Drug Delivery Systems. Part II: Flow and Transport Models

Darcy's law and Fick's law of Part I are combined with bulk and species conservation of mass equations, respectively, to obtain flow and transport models for swelling drug delivery systems. The model identifies three distinct regimes and makes the appropriate simplifying assumptions for each. The result is a set of highly nonlinear, coupled, integro‐partial differential equations. The advantage of this model is that it can be easily modified to account for multiple simplified scenarios and geometries. As an example, boundary conditions are given for a radially symmetric drug delivery device.