The robustness and parametric sensitivity of a high-shear wet granulation process during scale-up were investigated for a formulation containing over 50% by weight of a hydrophobic active pharmaceutical ingredient (API). The sensitivity of granule properties-such as particle site distribution, bulk density and dissolution rate with respect to both formulation (binder/solids ratio) and process parameters (agitation rate and wet massing time) was determined at three different scales (0.5, 4.0 and 25.0 L). For a fixed impeller speed at a given granulator scale, the dissolution rate was found to be strongly correlated with bulk density, and both parameters could be controlled relatively precisely by the wet massing time. However, during scale-up and for variable agitation rates (expressed by the dimensionless Froude number) dissolution rate was found to be a non-trivial function of both granule size distribution and granule density. A set of process parameters for which the formulation was robust during scale-up was identified. (C) 2015 Elsevier B.V. All rights reserved.