(380ae) Comparative Study of Mixing in a High Shear and Low Shear Blender Using Numerical Simulation

Comparative study of mixing in a high shear and low shear
blender using numerical simulation

Koyel Sen ¹, Natasha V Rodriguez ⁴,
Bodhi Chaudhuri ^1,2,3, Carl Anderson⁴

¹Department
of Pharmaceutical Sciences, University of Connecticut ²Department
of Chemical and Biomolecular Engineering, University of Connecticut ³Institute
of Material Sciences, University of Connecticut  ⁴Duquesne
University, Graduate School of Pharmaceutical Sciences

Correspondence: koyel.sen@uconn.edu

Background:

Mixing is one of the crucial unit
processing widely used in Pharmaceutical manufacturing to produce homogenized
mixture which further goes for other treatments e.g. tablet press, wet
granulation for tableting, capsule filling machine for capsules etc. The purpose of this comparative study is to understand and
evaluate the effect of shear on mixing in a high shear and low shear blender
using numerical simulation.

Methods:

Mixing
was simulated in a high shear and a bin blender using Discrete element modeling
or DEM. The computational geometries were generated according to lab-scale
blenders to minimize the experimental variability. The impeller of high shear
blenders was generated by gluing cohesive particles together. A multicomponent
mixture was used as the blend formulation. The characterization of mixing was
carried out using ‘box counting method’, measuring relative standard deviation
or RSD as a function of mixing time. The effect of operational parameters such
as fill percentage, loading pattern and rotational speed were observed to
determine the optimized blending process.

Results:

Simulated
result shows higher degree of mixing can be achieved in high shear compare to
low shear blender. It also shows that fill percentage, rotational speed and
loading pattern has a direct effect on the degree of mixing. The result shows
the impeller in high shear blender promotes diffusive transport of particles
which leads to quicker mixing.

Conclusions:

A
comparative study was carried out to explore the effect of shear on mixing
using Discrete Element Modelling. The blend used in the simulations consists
a multicomponent mixture. Simulation shows that high shear blender provides
quicker mixing comparatively. In both cases the operational parameters such as
loading pattern, rotational speed and fill percentage have shown significant
effect on the degree of mixing which complies with the previous single
component mixing literature.