Evaluation of the tensile strength of compacts using square samples produced through triaxial decompression

To achieve an improved characterization of risk in tableting, we produced square specimens using triaxial decompression after compaction of square specimens and measured their tensile strength by lateral compression. Their strength was compared against that of cylindrical samples produced by uniaxial unloading. Both sodium chloride and lactose 312 demonstrated the advantage of triaxial decompression to produce defect-free compacts. Using finite element analysis, we confirmed the stress state of the square specimen in lateral compression. All materials demonstrated higher tensile strength for triaxially decompressed specimens compared to cylindrical samples. We call the ratio of these two strengths the tableting risk ratio. This number indicates the risk of defect formation and its effect on the strength of the tablet during regular unloading and ejection. A graphical representation of the tableting risk ratio and the diametrical strength of different materials provides insight into the potential for defect formation in tableting. [Display omitted] •A new triaxial decompression setup is able to produce “defect free” samples.•Finite element analysis of lateral loading a triaxial sample for tensile test.•Tableting Risk Ratio: triaxial to uniaxial decompression compact tensile strengths.•A new quantitative risk assessment of tableting risk.