1. A novel approach to modelling
of tablet film-coating
Michael Lu, Joy Phophichitra
Dr Axel Zeitler

2. Motivation
Coated tablets are the dominant drug dosage form
Benefits: protect drug, mask taste, uniformity,
appearance, release profile
Batch process: Tablets are sprayed in a rotating drum
Complex multi-parameter system

3. Motivation
Many problems occur on a regular basis

4. Motivation
Better process understanding – basis for future process
improvement
Benefits of improved modelling:
Manufacturer - reduce expensive and time-consuming
trials
Regulator - compliance with FDA’s recent “quality by
design” initiative

5. Weaknesses of
Current approaches
Thermodynamic
models
Empirical
studies
Discrete element
model (DEM)
simulations
Limited
predictive power
No description of
film-forming
phenomena
Semi-empirical
Cannot translate
between coating
units
Many trials required
Most papers
concentrate on
isolated aspects
Large
computational
expense
Ray-tracing
spray coating
algorithm

6. Novel approach
“An all-encompassing model for film coating has not been
developed yet. In fact, one probably never will be.”
Ebey, 1987

7. Entire process had never been combined before:
Demonstrates holistic approach is possible
Links macroscale parameters to microstructural
processes
Large scope for further work and collaboration