100% visual inspection of tablets produced with continuous direct compression and coating
Visual appearance of tablets is an important property for patients. Since the visual appearance is most strongly influenced by the applied coating, this necessitates a high level of process control and homogeneity in the coating process. In recent years, a number of tablet coaters have been developed that can be used in combination with continuous tablet production lines.
Highlights
180 kg of tablets were produced with continuous direct compression at 25 kg/h.
Tablets were coated using a semi-batch drum coater in 15 kg lots.
All 877,470 coated tablets were visually inspected using an automatic sorting machine.
Low lot-to-lot variability and low number of defect tablets was observed.
The visual defects were the color deviation and edge chipping.
In this study, 180 kg of tablets were produced using a continuous direct compaction line with a throughput of 25 kg/h. Tablets were consequently subdivided into 12 lots and coated in a semi-batch drum coater directly after compression. For a detailed understanding of intra-lot and lot-to-lot variability, a 100% visual inspection of the tablets was performed using an automatic tablet inspection and sorting machine. All tablets were analyzed from all 6 sides and the unsuitable tablets were sorted out.
In the worst lot, only 1 out of around 300 tablets was sorted out due to color mismatch. For some tablets, edge chipping was also observed, which would presumably not be detected during routine sampling. Root causes for the defects could be found in the intentionally chosen set of old punches and in the operation parameters of the coater. Nonetheless, the lot-to-lot variability according to all criteria was very low.
Article information: Shirin Barimani, Rok Šibanc, Dejan Tomaževič, Robin Meier, Peter Kleinebudde, 100% visual inspection of tablets produced with continuous direct compression and coating, International Journal of Pharmaceutics, Volume 614, 2022. https://doi.org/10.1016/j.ijpharm.2022.121465.
Materials
The biconvex tablet cores comprised 49.5% (w/w) microcrystalline cellulose (Avicel® PH-102; FMC International, Little Island Co., Cork, Ireland (MCC)), 49.5% lactose monohydrate (Tablettose® 80; Meggle, Wasserburg, Germany and 1.0% (w/w) magnesium stearate (Peter Greven GmbH & Co. KG, Bad Münstereifel, Germany) as a lubricant. They had an average mass of 200.0 ± 0.5 mg. The diameter was 8.1 mm, the height 3.6 mm and the radius of curvature 11.0 mm.