(17d) Intra-Tablet Coating Uniformity of Various Pharmaceutical Tablet Shapes

Authors: 
Wassgren, C. R. - Presenter, Purdue University
Ketterhagen, W. R., Pfizer Worldwide Research and Development
Kumar, R., Purdue University
Freireich, B., The Dow Chemical Company

In this talk, we present recent computational and experimental work investigating intra-tablet coating variability.  Prior analytical work has shown that tablets having a preferential orientation when passing through the spray zone approach an asymptotic coating variability limit, with larger degrees of preferred orientation resulting in larger intra-tablet coating variability.  Discrete element method computer simulations predict this effect and produce coating patterns consistent with experimental measurements of coating thickness made using terahertz imaging.  Comparisons with Monte Carlo predictions based on tablet orientation distributions demonstrate that tablet obscuration due to neighboring tablets also significantly affects coating uniformity.