(208b) DEM Validation of Tablet Motion in a Vibratory Coating Pan

Discrete Element Method (DEM) modeling holds great promise for simulating tablet coating processes. This study presents a DEM model for simulating the movement of true biconvex tablet shapes in a vibrating coater pan, along with the experimental methods used to validate the model. High speed video imaging is used to measure the circulation speed of tablets in the experiments and comparisons with DEM simulations are made for a range of vibration amplitudes and frequencies.  Inputs to the DEM model, like tablet-tablet and tablet-wall friction coefficients are measured directly using a variation on the pin-on-disk apparatus and the coefficient of restitution values were obtained from literature. In addition, the sensitivity of the model to tablet-level parameters, including friction coefficients, coefficients of restitution, and contact stiffnesses, are presented. The tablet-wall friction coefficient was found to have a very strong influence on the circulation speed with the circulation speed increasing as the friction coefficient is increased. The coefficient of restitution was also found to have a significant effect on the circulation speed.