The determination of the mechanical properties of elongated tablets of varying cross section

The mechanical properties of elongated tablets of different thickness prepared at a range of pressures with surfaces that are flat or curved, have been determined by application of a flexure test. The strength of the tablets in terms of breaking load increases with an increase in the cross-sectional area of the tablets. To provide an improved method of comparing the strength of the tablets, the tensile strength of the specimens has been calculated from equations based on stress analysis. While an allowance for a change in thickness was provided by such a system there was a clear indication that the specimens tensile strength was still dependent on their dimensions. For equivalent central core thickness strength increased with the face curvature. This could be due to changes of the structure within the specimen during the formation process and there were clear indications that tablet porosities for equivalent compaction pressures were not equal. The differences could, however, be utilised to provide optimum conditions of curvature and central core thickness to give maximum tablet strength.