title: In-line implementation of an image-based particle size measurement tool to monitor hot-melt extruded pellets.
abstract: This work focuses on the implementation and application of an in-line particle measurement tool to monitor particle properties of hot-melt extruded pellets. A novel image analysis system (Eyecon) is used to analyze pellets with a size of approximately 1mm. The method is based on photometric stereo imaging, which is achieved by three different-colored light sources arranged circularly around the lens. Several implementations, whereby the product stream was led through the optical sampling volume, have been tested. The advantages and disadvantages of each implementation are discussed and evaluated. The most suitable implementation was applied to an extrusion run with constant throughput and different cutting frequencies resulting in different pellet sizes. A particle size distribution comparison between the image analysis system and an off-line reference particle analysis (QICPIC) showed good agreement although only a small fraction of the particles were analyzed in-line. Additionally, some illustrative examples for process development are given. With this approach the capability of hot-die face pelletizing to manufacture nearly-spherical pellets with a narrow size distribution is proven.
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13/2, 8010 Graz, Austria; Institute for Process and Particle Engineering, Graz University of Technology, Inffeldgasse 13/3, 8010 Graz, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Treffer
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13/2, 8010 Graz, Austria.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Wahl
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13/2, 8010 Graz, Austria.
authors.forename: Theresa R
authors.initials: TR
authors.lastname: Hörmann
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13/2, 8010 Graz, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Markl
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13/2, 8010 Graz, Austria; Institute for Process and Particle Engineering, Graz University of Technology, Inffeldgasse 13/3, 8010 Graz, Austria.
authors.forename: Simone
authors.initials: S
authors.lastname: Schrank
authors.affiliation: Innopharma Labs Inc., 311 Q House, 76 Furze Road, Dublin 18, Ireland.
authors.forename: Ian
authors.initials: I
authors.lastname: Jones
authors.affiliation: Innopharma Labs Inc., 311 Q House, 76 Furze Road, Dublin 18, Ireland.
authors.forename: Paul
authors.initials: P
authors.lastname: Cruise
authors.affiliation: Automatik Plastics Machinery GmbH, Ostring 19, 63762 Großostheim, Germany.
authors.forename: Reinhardt-Karsten
authors.initials: RK
authors.lastname: Mürb
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13/2, 8010 Graz, Austria.
authors.forename: Gerold
authors.initials: G
authors.lastname: Koscher
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13/2, 8010 Graz, Austria; Institute of Pharmaceutical Science, Department of Pharmaceutical Technology, University of Graz, Humboldtstraße 46, 8010 Graz, Austria.
authors.forename: Eva
authors.initials: E
authors.lastname: Roblegg
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13/2, 8010 Graz, Austria; Institute for Process and Particle Engineering, Graz University of Technology, Inffeldgasse 13/3, 8010 Graz, Austria. Electronic address: khinast@tugraz.at.
authors.forename: Johannes G
authors.initials: JG
authors.lastname: Khinast
mesh_terms: D000082:Acetaminophen / Q000737:chemistry; D004339:Drug Compounding / Q000295:instrumentation*; D006358:Hot Temperature; D007091:Image Processing, Computer-Assisted; D008027:Light; D009862:Online Systems; D010316:Particle Size; D013229:Stearic Acids / Q000737:chemistry
chemical_list: D013229:Stearic Acids; D000082:Acetaminophen; C031183:stearic acid
keywords: Hot-die face pelletizing; Hot-melt extrusion; Measurement position; Particle imaging; Process analytical technology