An investigation of the pore structure of tablets of sucrose and lactose by mercury porosimetry

The pore structure of tablets has been investigated by mercury porosimetry. Tablets, when prepared from ungranulated powder, showed a narrow pore size distribution, the mode of which decreased from 9 to 1 μm over the pressure range studied. Granulation caused the size distribution of tablet pores to widen. Large robust granules, compressed at low pressures, gave tablets with a bimodal pore size distribution. Decrease in granule size and strength, promoted a more uniform tablet structure and fine, friable, granules, compressed at high pressures, gave tablets with almost the same structure as those prepared from ungranulated powder.