Exploring the impact of formulation and tablet shape on tablet integrity: A comprehensive investigation using mechanical and imaging techniques

Tablets are subjected to collisions during processing and handling which can result in defects and even failed batches at commercial scale. This study investigated the influence of composition and tablet shape on the tablet integrity under simulated stressed settings. Tablet formulations with two filler combinations were compressed to different shapes and tensile strengths. Tablet integrity was characterized using tensile strength, friability, drop test, impact testing, indentation and X-ray microtomography. Pharmacopeial tests demonstrated that all tablets including the lowest tensile strength tablets had acceptable integrity. Impact testing and drop test provided stressed conditions to discriminate and rank the tablet integrity according to the composition and shape. Microtomography and indentation results revealed heterogenous density distribution with respect to tablet shape and the composition. Increasing the amount of microcrystalline cellulose was the most successful approach to address tablet integrity issues. Tablet shape also influenced the number as well as the nature of tablet defects. Application of more discriminating tests could serve as extra tools to support selection of right tablet shape and composition. This can lead to the development of a robust formulation with potential to save resource required for troubleshooting tablet defect during both clinical and commercial supply.