PREDICTING THE RELATIVE RATE OF WEAR OF PHARMACEUTICAL COMPACTS USING THE MECHANICAL-PROPERTIES OF THEIR CONSTITUENT CRYSTALS

The relative rate of wear of compacts under impact conditions of several model pharmaceutical substances (sucrose, acetaminophen, adipic acid, and sodium chloride) was modelled using the mechanical properties of single crystals of each substance. The hardness, average Young modulus, and toughness were previously determined using microindentation techniques. The effect of porosity was not examined. Instead, the first-order wear constant was plotted vs. tablet relative density. The simple model of tablet wear was able to normalize the experimental data for the materials tested to within experimental error, implying that wear is inversely proportional to the toughness and directly proportional to the ratio of hardness and Young modulus. © 1990.