Brittle fracture during tableting – a problem for the pharmaceutical industry

Brittle fracture refers to capping and lamination of tablets, which occurs at the point of ejection of the tablets from the machine dies. The problem is attributable primarily to the presence of entrapped air (voids) or low density regions in the tablets. The latter (low density region) is in turn associated with an uneven consolidation of the tablet during compaction. The voids or low-density regions constitute weak points in the tablet from which cracks emanate and propagate when the tablet is subjected to diametral stress (e.g. die wall pressure).