(776g) Discrete Element Modeling to Predict Pharmaceutical Powder Flow at Different Humidity Conditions

Authors: 
Mukherjee, R., UConn
Chattoraj, S., GlaxoSmithKline
Chaudhuri, B., University of Connecticut
Mao, C., Genentech
Pharmaceutical powder flow can alter significantly based on the exposed humidity conditions. Lack of predictive models to understand the flow variability at different humidity conditions may undermine its subsequent impediments. A Discrete Element Model (DEM) has been developed to predict the effects of humidity on powder flow, altering the cohesive forces based on granular bond numbers in simple hopper geometries. Experiments similar to the simulations are further performed for different pharmaceutical excipients at different humidity conditions. To predict cohesive properties for powders, those did not flow under gravity; vertical vibration has been introduced in both experiments and simulations. The equivalent DEM bond numbers are in good accordance with the experimental results. Pharmaceutical powders with lower moisture sorption show more variability in flow properties in comparison to cohesive powders having higher moisture contents. The equivalent DEM parameters suggest the same and are being implemented to predictpowder flow variability in different geometries and humidity conditions.