AAPS PharmSciTech

, Volume 14, Issue 1, pp 402–411 | Cite as

Experimental Analysis of Tablet Properties for Discrete Element Modeling of an Active Coating Process

  • Sarah Just
  • Gregor Toschkoff
  • Adrian Funke
  • Dejan Djuric
  • Georg Scharrer
  • Johannes Khinast
  • Klaus Knop
  • Peter Kleinebudde
Research Article


Coating of solid dosage forms is an important unit operation in the pharmaceutical industry. In recent years, numerical simulations of drug manufacturing processes have been gaining interest as process analytical technology tools. The discrete element method (DEM) in particular is suitable to model tablet-coating processes. For the development of accurate simulations, information on the material properties of the tablets is required. In this study, the mechanical parameters Young’s modulus, coefficient of restitution (CoR), and coefficients of friction (CoF) of gastrointestinal therapeutic systems (GITS) and of active-coated GITS were measured experimentally. The dynamic angle of repose of these tablets in a drum coater was investigated to revise the CoF. The resulting values were used as input data in DEM simulations to compare simulation and experiment. A mean value of Young’s modulus of 31.9 MPa was determined by the uniaxial compression test. The CoR was found to be 0.78. For both tablet–steel and tablet–tablet friction, active-coated GITS showed a higher CoF compared with GITS. According to the values of the dynamic angle of repose, the CoF was adjusted to obtain consistent tablet motion in the simulation and in the experiment. On the basis of this experimental characterization, mechanical parameters are integrated into DEM simulation programs to perform numerical analysis of coating processes.

Key words

active film coating DEM simulation dynamic angle of repose tablet coating tablet mechanical properties 


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Copyright information

© American Association of Pharmaceutical Scientists 2013

Authors and Affiliations

  • Sarah Just
    • 1
  • Gregor Toschkoff
    • 2
  • Adrian Funke
    • 3
  • Dejan Djuric
    • 4
  • Georg Scharrer
    • 2
  • Johannes Khinast
    • 2
  • Klaus Knop
    • 1
  • Peter Kleinebudde
    • 1
  1. 1.Institute of Pharmaceutics and BiopharmaceuticsHeinrich-Heine-UniversityDuesseldorfGermany
  2. 2.Research Center Pharmaceutical Engineering GmbHGrazAustria
  3. 3.Global Chemical and Pharmaceutical Development, Bayer Pharma AGBerlinGermany
  4. 4.L.B. Bohle Maschinen + Verfahren GmbHEnnigerlohGermany

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