Changes in the Particle Size and Size Distribution During Compaction of two Pharmaceutical Powders with Dissimilar Consolidation Mechanisms

Abstract

Five different size fractions (32–44 um, 53–63 urn, 75–90 um, 105–124 um, and 124–177 um) of heavy magnesium carbonate and Avicel PH102 were compressed into 12.5 mm diameter compacts by means of a hydraulic press at two pressures. Compacts of the 75–90 um fraction of both substances and their binary mixtures in three different ratios were also prepared at eight different pressures. The subsequent compacts were disintegrated by sonication, and the size of the resultant particles analysed. It was found that the median particle diameter of both powders and disintegrated compacts was affected by sonication time and by the amount of water present in the ultrasonic bath. However a standard method was established.

The results showed that the particle size of the disintegrated compacts might be affected by both the initial particle size and the differences in the consolidation mechanisms of these two substances. However changes in the particle size of the binary mixtures are dependent on the relative concentration and the consolidation mechanism of the components in the mixtures.