The Strength of Compressed Tablets

Abstract

Examination of the fracture of tablets in a strength test has revealed two types of failure. Where the interparticulate bond is strong, fracture occurs across the grains and the strength of tablet is a simple function of the particle size. If the interparticulate bond is weak, fracture occurs around the grain and particle size has little effect. A thin coating of stearic acid was used to weaken the interparticulate bond when the effect of grain size on strength disappeared or was reversed. The relation of bonding and capping is discussed and it is shown that capping can be reduced by weakening the interparticulate bond.