The intention of this study was to investigate the consolidation states of dilation of granular material with respect to mechanical shear, size and component fraction, geometry and scale of the processing equipment. Dilation of pharmaceutical powders and mixtures was measured in a rotating drum at various speeds of rotation (10, 15, 20, 25 rpm). It was interesting to note that the dilation did not change with an increase in the rotational rate of the cylinder. Furthermore, studies carried out in various sizes of cylinders showed that the dilation was poor in the lower and higher volume of cylinder. An optimum volume of the cylinder with highest dilation was found to exist in the middle scale. Decrease or increase in the cylinder volume hindered the dilation of powder. Lubricated blends exhibited higher bed density than the non-lubricated blends, and therefore showed lower dilation. More interestingly, higher dilation was achieved at 35-45% of fill level of cylinder. Any further increase or decrease of powder fill level beyond this range drastically decreased the ability of powders to dilate. Eventually, dilation of powders decreased with increased in powder bed density. Cohesive materials when mixed with free flowing powders could improve the flowability (reduced dilation) only when they constituted 40-60% of blend composition. Percentage of free flowing material below this composition was found to be ineffective in reducing the dilation. (C) 2015 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.