TY - JOUR
T1 - Understanding the correlations between tablet flow dynamics and coating uniformity in a pan coater
T2 - Experiments and simulations
AU - Chen, Jiale
AU - Yang, Qingliang
AU - Liu, Jinming
AU - Jin, Mengya
AU - He, Shaoqin
AU - Zhou, Xuhui
AU - Zhou, Hang
AU - Dong, Jie
AU - Yang, Gensheng
AU - Zhu, Jesse
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/9/1
Y1 - 2023/9/1
N2 - Coating uniformity is crucial for pharmaceutical solid dosages to ensure sufficient stability and to program drug release behavior. The present study aims to thoroughly investigate the correlation between the coating uniformity and the tablet flow dynamics with a novel computational model. The model was developed on discrete element method (DEM) coupled with the ray-tracing algorithm and was validated with experiments. Firstly, tablet flow dynamics and patterns were fully recorded and clearly categorized. By increasing the peripheral speed of the coating pan, the tablet flow pattern distinctly transited from slumping, rolling, cascading to cataracting, and the coefficient of variation to inter-tablet coating weight (CVI) was significantly reduced from 1.9 to 1.0, indicating the coating uniformity dramatically increased. But further increasing the peripheral speed, the tablet pattern approached the centrifuging status and the CVI value was reversely increased to 2.0, suggesting a reduction in uniformity. Interestingly, huge speed variations of the individual tablet (0–100 cm/s) occurred even in the same tablet pattern, this allowed an active tablet region for guiding the location of the coating nozzles. These results were consistent within the scale-up pan coaters with different transition values. Additionally, the case study showed that properly adjusting the shape and location of baffles could effectively accomplish the coating pattern (rolling and cascading) at a slower peripheral speed. These findings suggest that tablet flow dynamics has a strong impact on the coating uniformity and needs to be carefully manipulated with useful strategies such as tuning the operating parameters or applying internal baffles. The mathematic model developed by the current study has paved a new way to comprehensively understand the tablet coating mechanics.
AB - Coating uniformity is crucial for pharmaceutical solid dosages to ensure sufficient stability and to program drug release behavior. The present study aims to thoroughly investigate the correlation between the coating uniformity and the tablet flow dynamics with a novel computational model. The model was developed on discrete element method (DEM) coupled with the ray-tracing algorithm and was validated with experiments. Firstly, tablet flow dynamics and patterns were fully recorded and clearly categorized. By increasing the peripheral speed of the coating pan, the tablet flow pattern distinctly transited from slumping, rolling, cascading to cataracting, and the coefficient of variation to inter-tablet coating weight (CVI) was significantly reduced from 1.9 to 1.0, indicating the coating uniformity dramatically increased. But further increasing the peripheral speed, the tablet pattern approached the centrifuging status and the CVI value was reversely increased to 2.0, suggesting a reduction in uniformity. Interestingly, huge speed variations of the individual tablet (0–100 cm/s) occurred even in the same tablet pattern, this allowed an active tablet region for guiding the location of the coating nozzles. These results were consistent within the scale-up pan coaters with different transition values. Additionally, the case study showed that properly adjusting the shape and location of baffles could effectively accomplish the coating pattern (rolling and cascading) at a slower peripheral speed. These findings suggest that tablet flow dynamics has a strong impact on the coating uniformity and needs to be carefully manipulated with useful strategies such as tuning the operating parameters or applying internal baffles. The mathematic model developed by the current study has paved a new way to comprehensively understand the tablet coating mechanics.
KW - Coating uniformity
KW - DEM modeling
KW - Pan coater
KW - Tablet coating
KW - Tablet flow dynamics
KW - Tablet velocity
UR - http://www.scopus.com/inward/record.url?scp=85164477125&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2023.144392
DO - 10.1016/j.cej.2023.144392
M3 - Article
AN - SCOPUS:85164477125
SN - 1385-8947
VL - 471
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 144392
ER -