(697e) FEM Simulations on Tablet Impact

Pharmaceutical tablets go through a series of mechanically aggressive downstream operations, including film coating and packaging, before arriving in patients' hands. In these processes, many tablet/tablet and tablet/metal impacts can occur, resulting in elegance defects that are a product quality concern. Impact-related tablet elegance issues are affected by many factors, including material mechanical properties, tablet and equipment geometry, and process parameters.  A fundamental understanding of these variables is needed for better control and design of tablet geometry and manufacturing processes. Much effort has been made recently to explore the statistics of tablet impact forces, primarily during film coating, thanks to the expanding capacity of DEM simulations. A quantitative connection between such impacts and the resulting damage on a tablet is still lacking, and is the main focus of this work.

We present results from finite element (FEM) simulations of local stress dynamics on a tablet when it impacts a rigid plate. For a tablet with certain geometric features, the effect of impact angle, velocity, and the material properties are explored parametrically. With a proper yield criterion, such local stress values from simulations could potentially translate to the extent of tablet damage observed in experimental trials.  To verify this, we perform friability tests on tablets made with the same geometry as in the simulation, and compare the observed defects with numerical findings.