Abstract

This talk presents a novel tool for in-line monitoring of pharmaceutical spray coating processes for tablets and pellets by means of an OSeeT industrial optical coherence tomography (OCT) system. Coating thickness as a function of time can be measured for tablets in a drum coater and for pellets in a fluid bed coater. OCT can also be of value for more exotic applications like core-skin co-extrusion products among others.

The presentation will cover two main pillars: (1) introduction to the OCT technology and its applications and (2) a discussion about raw data definition and storage in high-speed imaging applications.

First, the physical principles behind OCT will be explained shortly, explaining why OCT does not need chemometric modelling. Further, a reference target for OCT will be presented, which can be used for routine calibration checks. Two method comparison studies show the correctness of the OCT results and contrast it to common off-line and in-line coating thickness measurements. This part will be concluded with application data from tablet and pellet coating.

OCT and other high-speed imaging methods, like near-infrared chemical imaging or image based particle size methods, share a common challenge. The sensor data generated during continuous measurement quickly hits the terabyte regions, which could become an IT administrator’s nightmare. OCT sensor data is about 1 terabyte per hour, while the results (information on coating thicknesses) take up less than 1 megabyte per hour. Regulators demand the storage of raw data. Thus, the definition of raw data needs to be somewhere in between sensor data and results only and needs to be wisely chosen. The preferred definition of raw data will be given and justified, as well as its impact on storage requirements.