Compression speed on polyethylene glycol and dicalcium phosphate tableted mixtures

The effect of compression speeds between 10-500 mm s^-1 on the compaction of PEG/DCP mixtures has been investigated using relative density (D₀), mean yield pressure, tensile strength, plastic energy (PE), work of failure (WF) and PE/WF ratio. At any speed, D₀ was found to increase with PEG concentration due to the smooth surface of PEG particles, and their lubricant activity reducing interparticulate friction. No synergistic interactions between PEG and DCP during compression with mean yield pressure occurred at the slowest compression speed (10 mm s^-1). However synergism was observed at higher compression speeds (100-500 mm s^-1) indicating DCP dominates compressibility with a reduction in plastic deformation of PEG. The tensile strength and normalized work of failure of the mixtures decreased with increasing compression speed. However they increased, reaching a maxima at 80:20 PEG/DCP (%), at all compression speeds. The plastic energy/work of failure ratio increased with speed. Increasing PEG, decreased the ratio and a minimum was observed at 80:20 PEG/DCP (%) where the least energy was required for making good tablets.