Effect of deaeration on processability of poorly flowing powders by roller compaction

Chenguang Wang, Zijian Wang, Albin Friedrich, Changquan Calvin Sun

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2 Scopus citations


Roller compaction (RC) is a common granulation process for manufacturing solid dosage forms. However, its applicability to the growing number of powders with very low bulk densities and high cohesiveness can be limited due to poor powder feeding. Although deaeration with a vacuum in the feeding line is an effective approach to enhance the powder feeding performance, a systematic assessment of its effects on RC process is lacking. In this work, we have examined the effect of vacuum on the processability of RC using an extremely poorly flowing powder, colloidal silica, and two grades of microcrystalline cellulose (MCC). A processable range is defined by roll speed and screw speed that attain stable feeding under the roller-gap controlled mode. A 0.35 barg vacuum level was sufficient to make the colloidal silica processable and a higher vacuum level solved the subfeeding issue and significantly expanded the RC operation range. In contrast, deaeration slightly narrowed the processable range for MCC PH105 and PH101, while only minimally affects the relationship between roll speed and screw speed. The effects of vacuum on the processability of these materials qualitatively correlated with the sensitivity of their bulk densities to pressure. A better understood effects of material properties (bulk density), process parameters (roller gap), and deaeration (vacuum level) on RC processability of powders help to determine an appropriate use of a vacuum line to improve the RC process.

Original languageEnglish (US)
Article number121803
Pages (from-to)121803
JournalInternational journal of pharmaceutics
StatePublished - Jun 10 2022

Bibliographical note

Funding Information:
Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from the NSF through the MRSEC (Award Number DMR-2011401) and the NNCI (Award Number ECCS-2025124) programs. CCS thanks the National Science Foundation for support through the Industry University Collaborative Research Center grant IIP-2137264, Center for Integrated Materials Science and Engineering for Pharmaceutical Products (CIMSEPP).

Publisher Copyright:
© 2022 Elsevier B.V.


  • Bulk density
  • Deaeration
  • Powder flow
  • Processability
  • Roller compaction
  • Vacuum

MRSEC Support

  • Shared

PubMed: MeSH publication types

  • Journal Article


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