A numerical tool to predict powder behaviour for pharmaceutical handling and processing

In this article, we discuss the potential of a numerical model to predict the behaviour of powders during pharmaceutical handling and processing. The model is based on the discrete element method (DEM) where simple experiments are required to calibrate the model used such as angle of repose tests. In a first step, the numerical calibration provided the coefficient of static friction and surface energy of the powders tested. This model has been validated with experimental data in different configurations: powder and granule settling by vibration, powder flow within a polydisperse system and mixing study in a rotary drum. Each comparison with the experimental data leads to a good accuracy of the model. In a second step, the method was used to predict numerically the granule formation during the wet granulation process and the manufacture of tablets during the compression process. Therefore, mixing (segregation), compression (mass uniformity and homogeneity of the components in the tablet) or cohesion problems can be modelled and predicted in order to limit some of the manufacturing problems during the industrialisation of pharmaceutical products such as granules or tablets, providing a scale-up of the process.