(159a) Modeling the Effect of Operational Parameters On High Shear Wet Granulation

High shear wet granulation is mainly aimed to improve the flowability of materials in solid dosage manufacturing processes. It also decreases segregation, reduces dust and modifies the appearance and properties of final product. However, it is a sensitive method that has not been fully understood since the particle growth dynamics are the result of different mechanisms that may take place simultaneously inside a granulator (e.g. wetting, coalescence, attrition). Therefore, it is important to implement the adequate modeling approach that could be used to describe the phenomena and propose process control algorithms.

Recent experimental findings have shown the effect of operational and design parameters on the high shear granulation performance. This work is focused on the study of the impeller velocity and design, which plays a fundamental role as it determines the way in which the energy is transmitted to the material and the collisions between particles. The objective was to propose and implement a modeling method that takes into account this design parameter.

Validation experiments were performed in a laboratory-scale high shear granulator using a lactose-based formulation as model system and a diluted Povidone solution as binder. A factorial design was implemented using three-bladed impellers at different blade angles (42°, 90° and 127°) and agitation velocities (450 rpm, 620 rpm and 807 rpm). Early-stage growth kinetics was determined performing granulations at 6 different massing times from 15 s to 150 s after wetting stage.

Regime maps were proposed and a mathematical model was developed based on a population balance approach to describe and quantify the influence of the blade angle and its interaction with the impeller velocity.