Effect of Mechanical and Formulation Variables on Granule Flowability in High-Shear Wet Granulation

This study investigates the effects of crucial process factors in high-shear wet granulation (HSWG) on the flowability of riboflavin-based granules.Using a 2⁴ complete factorial design, the effects of binder type, binder concentration, chopper speed, and impeller speed were thoroughly evaluated during sixteen experimental runs.The granule flowability was assessed using measurements of the angle of repose.The results showed that chopper speed, binder type, and binder concentration had a substantial effect on flowability, while impeller speed had a modest effect.Higher chopper speeds enhanced flow by reducing agglomeration size and increasing granule homogeneity, particularly in PVP-based formulations.HPMC-based formulations demonstrated higher sensitivity to processing parameters because of their inherent cohesiveness, thus requiring careful mechanical energy input adjustment.The three-way interaction between binder type, chopper speed, and impeller speed was particularly significant, emphasising the need to consider the combined effects of process variables.At 2.5% HPMC binder concentration, 2500 rpm chopper speed, and 60 rpm impeller speed, the best flowability of 27.08 was observed.These findings provide a solid basis for process optimisation in HSWG and help maintain regular granule flow parameters, which are essential for reliable tablet manufacturing.