White Paper: Key Factors Influencing Measured Tablet Hardness

Measuring tablet hardness (breaking force) plays a vital role in defining dosage form with optimum physical characteristics and testing whether produced dosage form meets the defined specifications in manufacturing. Testing tablet hardness is more than ensuring the mechanical integrity of produced tablets during subsequent processes. Because the hardness of a tablet directly relates to all other physical parameters, it is a fast and efficient test that indicates whether specifications such as disintegration time and friability will be met. It is therefore essential, that hardness measurement is done correctly – and that the equipment used to test tablet hardness guarantees repeatable results.

As mentioned in both US and European Pharmacopeia, the term "hardness" is actually misleading in a scientific sense, but commonly used as a synonym for breaking force or resistance to crushing strength. In simple terms, tablet hardness is the force (load) required to break a tablet. Pharmacopeia also gives some requirements as to how the tablet should be tested including basic design specifications for the tester.