Strength Simulation of Scored Tablets Based on the Finite Element Method Using an Extreme Vertices Design

Abstract

The mechanical strain distribution of scored tablets was simulated using the finite element method (FEM). The score was fabricated as a triangular runnel with the pole on the top surface of flat tablets. The effect of diametral compression on the tablet surface strain was evaluated by changing the angle between the scored line and the diametral compression axis. Ten types of granules were prepared according to an extreme vertices design. Young's modulus and the Poisson ratio for the model powder bed were measured as elastic parameters. The FEM simulation was then applied to the scored tablets represented as a continuous elastic model. Strain distributions in the inner structure of the tablets were simulated after the application of external force. The maximum principal strain (ε) value was obtained with tablets containing a large amount of corn starch, in all scored line positions. In contrast, the ε value of the tablets containing a large amount of microcrystalline cellulose was minimal. The adequacy of the simulation was evaluated by experiments with scored tablets. The results indicated a fairly good agreement between the FEM simulation and experiments. Moreover, it was found that the ε value correlated negatively with the value of tablet hardness. These results suggest that the FEM simulation was advantageous for designing scored tablets.

A Method for the Tensile Strength Prediction of Tablets with Differing Powder Plasticities

“…The relationship between the remaining strain and the tablet strength is often considered through numerical analyses using the finite element method. 10,11) The compression process induces significant densification of the powder bed owing to particle rearrangement and deformation. High compression pressure increases both the coordination number and contact area between the particles.…”