Power consumption profiles in high-shear wet granulation. I: Liquid distribution in relation to powder and binder properties

Wet granulation processes frequently rely on the device power consumption p rofile to monitor the process endpoint. This work shows how the observed po wer consumption relates to the physical properties of the mass. The liquid binder was traced with a fluorescent marker and the liquid distribution cou ld be followed during the process. It was found that primary agglomerates f orm in the reactor, the shape and composition of which depend on the wettab ility of the starting powders by the liquid binder. An increase of the devi ce power consumption is conditional to the disruption of these primary aggl omerates, Increasing the viscosity of liquid binders up to 250 mPa . s had no significant effect on the power consumption. Eventually, the lower surfa ce tension liquid binders yielded greater energy consumption, indicating th at interparticle friction forces had a great impact on the device power con sumption. (C) 2001 Wiley-Liss, Inc.