Figure 1: STAR-CCM+ simulation
with DEM showing
inside a tablet die.
Variations in color
reflect the non-uni-formity of the granule distribution.
as non-stop end-to-end processing, and the push to build
quality and efficiency into production, solid dose tablet
manufacturers have a challenging road ahead of them because they must pinpoint the key factors and requirements
that will lead to robust and repeatable processes, resulting
in superior products.
WHY NUMERICAL SIMULATIONS?
Multi-physics Computational Fluid Dynamics (CFD) is a
numerical method for predicting the coupled behavior of
fluid, gas and particulate flows including heat and mass
transport. A significant advantage of using numerical simulations is that it allows for the validation of a design or
process before physical tests need to be carried out. For
example, the development of a new tablet shape or coating
material calls for performing an extensive number of costly
and time-consuming experiments to avoid unexpected
variations, identify unpredictable process parameters and
address scale-up problems. Studying these effects through
numerical simulations can greatly reduce time, material and
development costs. In addition, numerical visualization tools
offer a wealth of detailed information, not always readily
available from experimental tests. This not only results in
Solid dose tablet manufacturing processes often lack reliability and robustness as a result of errors in production and a shortfall in process control. Facing unprecedented economic pressures, pharmaceutical manufacturing companies are continuously
looking to improve on the quality of their products and the
productivity of their processes. Multi-physics numerical
simulation is emerging as game-changing technology to help
step up efficiency, enhance quality, and shorten time-to-market through virtual prototyping and optimization.
CHALLENGES OF SOLID DOSE TABLET
Tableting (compression from a powder into a solid dose
tablet) and tablet coating are two vitally important steps in
the tablet manufacturing process that ultimately determine
the weight, thickness, density, hardness and coating of the
final solid dosage form. Variability in any of these attributes
not only negatively impacts the release profile and therapeutic efficacy of the medicine, it alters the disintegration and
dissolution properties of the tablet, leads to tablet defects
and causes breakage during bulk packaging and transport.
With the adoption of novel manufacturing processes such
■ By Sabine Goodwin, Senior Engineer, Technical Marketing; Dr. Oleh Baran, Application Specialist;
Dr. Kristian Debus, Director, Life Sciences; CD-adapco
Improving reliability and robustness in solid dosage manufacturing
Numerical Simulations for
Tableting & Coating
■ 32 MAY 2014 | PHARMACEUTICAL PROCESSING
■ PHARMPRO. COM