Process modeling in the pharmaceutical industry using the discrete element method.

The discrete element method (DEM) is widely used to model a range of processes across many industries. This paper reviews current DEM models for several common pharmaceutical processes including material transport and storage, blending, granulation, milling, compression, and film coating. The studies described in this review yielded interesting results that provided insight into the effects of various material properties and operating conditions on pharmaceutical processes. Additionally, some basic elements common to most DEM models are overviewed. A discussion of some common model extensions such as nonspherical particle shapes, noncontact forces, and interstitial fluids is also presented. While these more complex systems have been the focus of many recent studies, considerable work must still be completed to gain a better understanding of how they can affect the processing behavior of bulk solids.