title: Monitoring of a Hot Melt Coating Process via a Novel Multipoint Near-Infrared Spectrometer.
abstract: The aim of the present work was to develop a PAT strategy for the supervision of hot melt coating processes. Optical fibers were placed at various positions in the process chamber of a fluid bed device. Experiments were performed to determine the most suitable position for in-line process monitoring, taking into account such requirements as a good signal to noise ratio, the mitigation of dead zones, the ability to monitor the product over the entire process, and reproducibility. The experimental evidence suggested that the position at medium fluid bed height, looking towards the center, i.e., normal to particle movement, proved to be the most reliable position. In this study, the advantages of multipoint monitoring are shown, and an in-line-implementation was created. This enabled the real-time supervision of the process, including the fast detection of inhomogeneities and disturbances in the process chamber, and the compensation of sensor malfunction. In addition, a model for estimating the particle size distribution via NIR was successfully created. This ensures that the quality of the product and the endpoint of the coating process can be determined correctly.
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Graz, Austria.
authors.forename: Roland
authors.initials: R
authors.lastname: Hohl
authors.affiliation: Institute for Process and Particle Engineering, Graz University of Technology, Graz, Austria.
authors.forename: Otto
authors.initials: O
authors.lastname: Scheibelhofer
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Graz, Austria.
authors.forename: Elena
authors.initials: E
authors.lastname: Stocker
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Graz, Austria.
authors.forename: Sharareh Salar
authors.initials: SS
authors.lastname: Behzadi
authors.affiliation: Hermes Arzneimittel GmbH, Großhesselohe, Germany.
authors.forename: Detlev
authors.initials: D
authors.lastname: Haack
authors.affiliation: Romaco Innojet, Steinen, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Koch
authors.affiliation: EVK DI Kerschhaggl GmbH, Raaba, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Kerschhaggl
authors.affiliation: CREMER OLEO GmbH & Co. KG, Witten, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Lochmann
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Graz, Austria.
authors.forename: Stephan
authors.initials: S
authors.lastname: Sacher
authors.affiliation: Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology, University of Graz, Graz, Austria. andreas.zimmer@uni-graz.at.
authors.forename: Andreas
authors.initials: A
authors.lastname: Zimmer
mesh_terms: D010316:Particle Size; D015203:Reproducibility of Results; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D013678:Technology, Pharmaceutical / Q000379:methods*
keywords: NIR; PAT; coating; hot melt coating