title: Magnetic resonance imaging and image analysis for assessment of HPMC matrix tablets structural evolution in USP Apparatus 4.
abstract: OBJECTIVE
  The purpose of the study was to present a methodology for the processing of Magnetic Resonance Imaging (MRI) data for the quantification of the dosage form matrix evolution during drug dissolution. The results of the study were verified by comparison with other approaches presented in literature.
  
  
  METHODS
  A commercially available, HPMC-based quetiapine fumarate tablet was studied with a 4.7T MR system. Imaging was performed inside an MRI probe-head coupled with a flow-through cell for 12 h in circulating water. The images were segmented into three regions using threshold-based segmentation algorithms due to trimodal structure of the image intensity histograms.
  
  
  RESULTS
  Temporal evolution of dry glassy, swollen glassy and gel regions was monitored. The characteristic features were observed: initial high expansion rate of the swollen glassy and gel layers due to initial water uptake, dry glassy core disappearance and maximum area of swollen glassy region at 4 h, and subsequent gel layer thickness increase at the expense of swollen glassy layer.
  
  
  CONCLUSIONS
  The temporal evolution of an HPMC-based tablet by means of noninvasive MRI integrated with USP Apparatus 4 was found to be consistent with both the theoretical model based on polymer disentanglement concentration and experimental VIS/FTIR studies.
authors.affiliation: Department of Magnetic Resonance Imaging, Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Kraków, Poland. Piotr.Kulinowski@ifj.edu.pl
authors.forename: Piotr
authors.initials: P
authors.lastname: Kulinowski
authors.forename: Przemysław
authors.initials: P
authors.lastname: Dorożyński
authors.forename: Anna
authors.initials: A
authors.lastname: Młynarczyk
authors.forename: Władysław P
authors.initials: WP
authors.lastname: Węglarz
mesh_terms: D007785:Lactose / Q000031:analogs & derivatives* / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D012995:Solubility; D013607:Tablets / Q000737:chemistry
chemical_list: D004364:Pharmaceutical Preparations; D013607:Tablets; C509290:hydroxypropylmethylcellulose-lactose matrix; D008747:Methylcellulose; D007785:Lactose