Pei, Chunlei, Lin, Hungyen, Markl, Daniel, Shen, Yao-Chun ORCID: 0000-0002-8915-1993, Zeitler, J Axel and Elliott, James A
(2018)
A quantitative comparison of in-line coating thickness distributions obtained from a pharmaceutical tablet mixing process using discrete element method and terahertz pulsed imaging.
CHEMICAL ENGINEERING SCIENCE, 192.
pp. 34-45.
Abstract
The application of terahertz pulsed imaging (TPI) in an in-line configuration to monitor the coating thickness distribution of pharmaceutical tablets has the potential to improve the performance and quality of the spray coating process. In this study, an in-line TPI method is used to measure coating thickness distributions on pre-coated tablets during mixing in a rotating pan, and compared with results obtained numerically using the discrete element method (DEM) combined with a ray-tracing technique. The hit rates (i.e. the number of successful coating thickness measurements per minute) obtained from both terahertz in-line experiments and the DEM/ray-tracing simulations are in good agreement, and both increase with the number of baffles in the mixing pan. We demonstrate that the coating thickness variability as determined from the ray-traced data and the terahertz in-line measurements represents mainly the intra-tablet variability due to relatively uniform mean coating thickness across tablets. The mean coating thickness of the ray-traced data from the numerical simulations agrees well with the mean coating thickness as determined by the off-line TPI measurements. The mean coating thickness of in-line TPI measurements is slightly higher than that of the off-line measurements. This discrepancy can be corrected based on the cap-to-band surface area ratio of the tablet and the cap-to-band sampling ratio obtained from ray-tracing simulations: the corrected mean coating thickness of the in-line TPI measurements shows a better agreement with that of the off-line measurements.
Item Type: | Article |
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Additional Information: | publisher: Elsevier articletitle: A quantitative comparison of in-line coating thickness distributions obtained from a pharmaceutical tablet mixing process using discrete element method and terahertz pulsed imaging journaltitle: Chemical Engineering Science articlelink: https://doi.org/10.1016/j.ces.2018.06.045 content_type: article copyright: © 2018 Published by Elsevier Ltd. |
Uncontrolled Keywords: | Terahertz in-line sensing, Terahertz pulsed imaging, Coating thickness variability, Discrete element method, Pharmaceutical coating |
Depositing User: | Symplectic Admin |
Date Deposited: | 14 Nov 2018 10:30 |
Last Modified: | 19 Jan 2023 01:13 |
DOI: | 10.1016/j.ces.2018.06.045 |
Open Access URL: | https://www.repository.cam.ac.uk/handle/1810/28410... |
Related URLs: | |
URI: | https://livrepository.liverpool.ac.uk/id/eprint/3028721 |