Pharmaceutical powders can exhibit markedly different tablet ejection forces.  The aim of this presentation is to study the factors leading to the variability of the tablet ejection force and its sensitivity to lubrication.  Our study showed that the tablet ejection force is mainly governed by 1) compact-die wall friction coefficient, and 2) residual die wall stress upon ejection; the latter was further controlled by the maximum compression pressure, as well as the deviation of the powder from the isotropic, linear elastic behavior during compression.  Brittle powders, such as lactose or dicalcium phosphate, exhibit exceeding ejection force because of their significant deviation from linear elasticity.  A mathematical model, by taking into consideration these attributes, was developed and shown to accurately predict of the tablet ejection forces.  Additionally, we found that boundary lubrication was highly effective in reducing tablet ejection force, achievable through decreasing the compact-die wall friction coefficient, but not through altering the intrinsic consolidation behavior of powders.  High ejection force is indicative of the sub-optimal stress condition of the tablet post-unloading.  Therefore learnings from this study are beneficial for formulators to harness the ejection force as an effective metric to identify and mitigate risks of tablet defects.