title: In-Line Monitoring of a Pharmaceutical Pan Coating Process by Optical Coherence Tomography.
abstract: This work demonstrates a new in-line measurement technique for monitoring the coating growth of randomly moving tablets in a pan coating process. In-line quality control is performed by an optical coherence tomography (OCT) sensor allowing nondestructive and contact-free acquisition of cross-section images of film coatings in real time. The coating thickness can be determined directly from these OCT images and no chemometric calibration models are required for quantification. Coating thickness measurements are extracted from the images by a fully automated algorithm. Results of the in-line measurements are validated using off-line OCT images, thickness calculations from tablet dimension measurements, and weight gain measurements. Validation measurements are performed on sample tablets periodically removed from the process during production. Reproducibility of the results is demonstrated by three batches produced under the same process conditions. OCT enables a multiple direct measurement of the coating thickness on individual tablets rather than providing the average coating thickness of a large number of tablets. This gives substantially more information about the coating quality, that is, intra- and intertablet coating variability, than standard quality control methods.
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Graz, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Markl
authors.affiliation: Research Center for Non-Destructive Testing GmbH, Linz, Austria.
authors.forename: Günther
authors.initials: G
authors.lastname: Hannesschläger
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Graz, Austria.
authors.forename: Stephan
authors.initials: S
authors.lastname: Sacher
authors.affiliation: Research Center for Non-Destructive Testing GmbH, Linz, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Leitner
authors.affiliation: Research Center for Non-Destructive Testing GmbH, Linz, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Buchsbaum
authors.affiliation: ProCept nv, Zelzate, Belgium.
authors.forename: Russel
authors.initials: R
authors.lastname: Pescod
authors.affiliation: ProCept nv, Zelzate, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Baele
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Graz, Austria.|Institute for Process and Particle Engineering, Graz University of Technology, Graz, Austria.
authors.forename: Johannes G
authors.initials: JG
authors.lastname: Khinast
mesh_terms: D001331:Automation; D055598:Chemical Phenomena; D002951:Citrates / Q000737:chemistry; D004339:Drug Compounding / Q000379:methods*; D005079:Excipients / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D008689:Methacrylates / Q000737:chemistry; D010968:Plasticizers / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011786:Quality Control; D015203:Reproducibility of Results; D013499:Surface Properties; D013608:Tablets, Enteric-Coated / Q000737:chemistry*; D013627:Talc / Q000737:chemistry; D041623:Tomography, Optical Coherence
chemical_list: D002951:Citrates; C477852:Eudragit L 30 D-55; D005079:Excipients; D008689:Methacrylates; D010968:Plasticizers; D011108:Polymers; D013608:Tablets, Enteric-Coated; D013627:Talc; C023001:ethyl citrate
keywords: algorithm; coating; image analysis; imaging methods; in-line quality control; optical coherence tomography; pharmaceutical film-coated tablets; processing