Effect of Process Variables on the Drucker–Prager Cap Model and Residual Stress Distribution of Tablets Estimated by the Finite Element Method

A multivariate statistical technique was applied to clarify the causal correlation between variables in the manufacturing process and the residual stress distribution of tablets. Theophylline tablets were prepared according to a Box–Behnken design using the wet granulation method. Water amounts (X1), kneading time (X2), lubricant-mixing time (X3), and compression force (X4) were selected as design variables. The Drucker–Prager cap (DPC) model...