Impact of Different Dry and Wet Granulation Techniques on Granule and Tablet Properties: A Comparative Study

Abstract

Four granulation techniques were compared evaluating their impact on granule properties and the tablet tensile strength. A common formulation was chosen to be processed with both wet and dry granulation techniques: roll compaction/dry granulation, high-shear granulation, twin-screw granulation, and fluidized-bed granulation. The produced granules were characterized in terms of granule size distribution, X-ray powder diffraction, scanning electron microscopy, porosity, and strength. Granules were tableted, and the tablets were evaluated in terms of tensile strength and mass variation. A particular focus was given to granule strength measurements. Granule strength showed to be strongly affected by the used granulation technique. Moreover, a nonlinear inverse correlation was identified between granule strength and tablet tensile strength. High-shear granulation produced the densest and strongest granules, which presented the lowest tablet tensile strength. Granules manufactured by roll compaction/dry granulation showed no loss in tabletability with the used formulation even for the more compacted and strong granules. Tablets produced by the fluidized-bed granulation showed the best properties in terms of tensile strength and mass variation. However, twin-screw granulation presented comparable results for the specific formulation evaluated in the study, thus revealing a great potential of this technique.

Keywords: dry granulation; granule size; granule strength; tablet; tensile strength; wet granulation.