Quantifying effects of particulate properties on powder flow properties using a ring shear tester

Research output: Contribution to journalArticlepeer-review

136 Scopus citations

Abstract

Effects of particle size, morphology, particle density, and surface silicification, on powder flow properties were investigated using a ring shear tester. Flow properties were quantified by flow function (FF), that is, unconfined yield strength, fc, as a function of major principal stress. A total of 11 powders from three series of microcrystalline cellulose (MCC): Avicel (regular MCC, elongated particles), Prosolv (silicified MCC, elongated particles), and Celphere (spherical MCC), were studied. Particle size distribution in each type of MCC was systematically different. Within each series, smaller particles always led to poorer powder flow properties. The slope of FF line was correlated to degree of powder consolidation by external stress. A key mechanism of the detrimental effect of particle size reduction on flow properties was the larger powder specific surface area. Flow properties of Celphere were significantly better than Avicel of comparable particles size, suggesting spherical morphology promoted better powder flow properties. Flow properties of powders different in densities but similar in particle size, shape, and surface properties were similar. When corrected for density effect, higher particle density corresponded to better flow behavior. Surface silicification significantly improved flow properties of finer MCC, but did not improve those of coarser.

Original languageEnglish (US)
Pages (from-to)4030-4039
Number of pages10
JournalJournal of Pharmaceutical Sciences
Volume97
Issue number9
DOIs
StatePublished - Sep 2008

Keywords

  • Flow function
  • Microcrystalline cellulose
  • Particle density
  • Particle shape
  • Particle size
  • Powder flow properties
  • Ring shear tester
  • Surface silicification

Fingerprint

Dive into the research topics of 'Quantifying effects of particulate properties on powder flow properties using a ring shear tester'. Together they form a unique fingerprint.

Cite this