DEM based computational model to predict moisture induced cohesion in pharmaceutical powders.

Pharmaceutical powder flow can alter significantly based on the exposed humidity conditions, and lack of computational models to predict the same may undermine process development, optimization, and scale-up performances. A Discrete Element Model (DEM) is proposed to predict the effects of humidity on pharmaceutical powder flow by altering the cohesive forces based on granular bond numbers in simple hopper geometries. Experiments analogous to the simulations are further performed for three commonly used pharmaceutical excipients at 20%, 40% and 60% RH. The equivalent DEM based bond numbers to predict the powder flow tendencies are in good accordance with the experimental results and can be a useful tool to predict the outcomes of different pharmaceutical processing techniques at various humidity conditions.