Title
Kinetic energy density and agglomerate abrasion rate during blending of agglomerates into powders
Author
Willemsz, T.A.
Hooijmaijers, R.
Rubingh, C.M.
Tran, T.N.
Frijlink, H.W.
Vromans, H.
Maarschalk, K.V.D.V.
Publication year
2012
Abstract
Problems related to the blending of a cohesive powder with a free flowing bulk powder are frequently encountered in the pharmaceutical industry. The cohesive powder often forms lumps or agglomerates which are not dispersed during the mixing process and are therefore detrimental to blend uniformity. Achieving sufficient blend uniformity requires that the blending conditions are able to break up agglomerates, which is often an abrasion process. This study was based on the assumption that the abrasion rate of agglomerates determines the required blending time. It is shown that the kinetic energy density of the moving powder bed is a relevant parameter which correlates with the abrasion rate of agglomerates. However, aspects related to the strength of agglomerates should also be considered. For this reason the Stokes abrasion number (St Abr) has been defined. This parameter describes the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. The StAbr number is shown to predict the abrasion potential of agglomerates in the dry-mixing process. It appeared possible to include effects of filler particle size and impeller rotational rate into this concept. A clear relationship between abrasion rate of agglomerates and the value of StAbr was demonstrated. © 2011 Elsevier B.V. All rights reserved.
Subject
Life
QS - Quality & Safety
EELS - Earth, Environmental and Life Sciences
Biology
Healthy Living
Abrasion
Agglomerate
Brittle calibrated test particle
Dry blending
High shear mixer
Stokes
To reference this document use:
http://resolver.tudelft.nl/uuid:55995010-129f-407e-9605-700768894d26
DOI
https://doi.org/10.1016/j.ejps.2011.11.01
TNO identifier
445054
ISSN
0928-0987
Source
European Journal of Pharmaceutical Sciences, 45 (1-2), 211-215
Document type
article