title: Optical coherence tomography as a novel tool for in-line monitoring of a pharmaceutical film-coating process.
abstract: Optical coherence tomography (OCT) is a contact-free non-destructive high-resolution imaging technique based on low-coherence interferometry. This study investigates the application of spectral-domain OCT as an in-line quality control tool for monitoring pharmaceutical film-coated tablets. OCT images of several commercially-available film-coated tablets of different shapes, formulations and coating thicknesses were captured off-line using two OCT systems with centre wavelengths of 830nm and 1325nm. Based on the off-line image evaluation, another OCT system operating at a shorter wavelength was selected to study the feasibility of OCT as an in-line monitoring method. Since in spectral-domain OCT motion artefacts can occur as a result of the tablet or sensor head movement, a basic understanding of the relationship between the tablet speed and the motion effects is essential for correct quantifying and qualifying of the tablet coating. Experimental data was acquired by moving the sensor head of the OCT system across a static tablet bed. Although examining the homogeneity of the coating turned more difficult with increasing transverse speed of the tablets, the determination of the coating thickness was still highly accurate at a speed up to 0.7m/s. The presented OCT setup enables the investigation of the intra- and inter-tablet coating uniformity in-line during the coating process.
authors: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13, 8010 Graz, Austria.
authors: Daniel
authors: D
authors: Markl
authors: Research Center for Non-Destructive Testing GmbH, Science Park 2, 2. OG, Altenberger Strasse 69, 4040 Linz, Austria.
authors: Günther
authors: G
authors: Hannesschläger
authors: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13, 8010 Graz, Austria.
authors: Stephan
authors: S
authors: Sacher
authors: Research Center for Non-Destructive Testing GmbH, Science Park 2, 2. OG, Altenberger Strasse 69, 4040 Linz, Austria.
authors: Michael
authors: M
authors: Leitner
authors: Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13, 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: Johannes G
authors: JG
authors: Khinast
mesh_terms: D002626:Chemistry, Pharmaceutical; D005240:Feasibility Studies; D008956:Models, Chemical; D015233:Models, Statistical; D011786:Quality Control; D013607:Tablets; D013678:Technology, Pharmaceutical / Q000379:methods* / Q000592:standards; D041623:Tomography, Optical Coherence / Q000592:standards
chemical_list: D013607:Tablets
keywords: In-line monitoring; Non-destructive testing; Optical coherence tomography; Pharmaceutical film-coated tablets; Quality control