Authors: John C. Strong (AbbVie)

Pharmaceutical formulations begin development on the lab bench and are initially assessed for how well they compress into tablets using a manual lab press, which slowly compresses one tablet at a time, or using a small low speed rotary press. However, for formulations that exhibit compression speed sensitivity, the results obtained in the pilot plant or manufacturing plant may be quite different than what was initially determined on the lab press. One method commonly used by drug manufacturers to mitigate the usually deleterious effect of speed on tablet density and strength is to increase the “dwell time”, which can be done by switching to a tooling design with an increased head flat diameter. However, researchers have also identified strain rate as having a large impact on tablet properties irrespective of dwell time. The goal of this study was to isolate the individual impact of strain rate and dwell time on tablet properties so that strategic scale-up can be achieved.