Combination of finite element method and Drucker-Prager Cap material model for simulation of pharmaceutical tableting process

Density-dependent Drucker-Prager Cap (DPC) model is widely used for assessing the compaction behaviour of powders due to its capability of capturing the various phenomena associated with the powder compaction process such as work hardening, nonlinear densification, and frictional and compressible behaviour of the powder. This paper presents a full description of the Drucker-Prager Cap model for the compaction behaviour of microcrystalline cellulose (MCC) Avicel PH101 pharmaceutical powder. The experimental calibration process of Drucker-Prager Cap is detailed and all model parameters are calculated as a function of powder relative density. Also, the calibrated parameters are implemented in finite element code to perform a numerical simulation of a typical pharmaceutical tablet. The results showed that the finite element model (FEM) was able to accurately predict the compaction behaviour of the microcrystalline cellulose powder. Furthermore, the finite element predictions of stress and density distributions of the powders during the compaction were used to analyse the failure mechanisms associated with tableting.