Lum S K, Hoag S W, Duncan-Hewitt W C
Faculty of Pharmacy, University of Toronto, 19 Russell Street, Toronto, Ontario, Canada M5S 2S2.
J Pharm Sci. 1998 Aug;87(8):909-16. doi: 10.1021/js9801079.
A micromechanical model for predicting the densification of particulate matter under hydrostatic loading was developed to account for the time-dependent response of materials to applied loads. Viscoelastic material response used in the analysis was based upon a standard three-parameter rheological model. Compaction data under closed die conditions were collected using an Instron analyzer for different rates of applied load. Densification during the loading phase of PMMA/coMMA powder, a pharmaceutical polymeric coating material, was well predicted by the proposed algorithm, which contrasts with the prediction implied through a static indentation model. Secondary factors which affect compaction such as die-wall friction are also briefly discussed.
