title: Quantitative image analysis for evaluating the coating thickness and pore distribution in coated small particles.
abstract: OBJECTIVE
  This study aims to develop a characterization method for coating structure based on image analysis, which is particularly promising for the rational design of coated particles in the pharmaceutical industry.
  
  
  METHODS
  The method applies the MATLAB image processing toolbox to images of coated particles taken with Confocal Laser Scanning Microscopy (CSLM). The coating thicknesses have been determined along the particle perimeter, from which a statistical analysis could be performed to obtain relevant thickness properties, e.g. the minimum coating thickness and the span of the thickness distribution. The characterization of the pore structure involved a proper segmentation of pores from the coating and a granulometry operation.
  
  
  RESULTS
  The presented method facilitates the quantification of porosity, thickness and pore size distribution of a coating. These parameters are considered the important coating properties, which are critical to coating functionality. Additionally, the effect of the coating process variations on coating quality can straight-forwardly be assessed.
  
  
  CONCLUSIONS
  Enabling a good characterization of the coating qualities, the presented method can be used as a fast and effective tool to predict coating functionality. This approach also enables the influence of different process conditions on coating properties to be effectively monitored, which latterly leads to process tailoring.
authors.affiliation: Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, A. Deusinglaan 1, 9713 AV, Groningen, The Netherlands. F.L.Laksmana@gmail.com
authors.forename: F L
authors.initials: FL
authors.lastname: Laksmana
authors.forename: L J
authors.initials: LJ
authors.lastname: Van Vliet
authors.forename: P J A
authors.initials: PJ
authors.lastname: Hartman Kok
authors.forename: H
authors.initials: H
authors.lastname: Vromans
authors.forename: H W
authors.initials: HW
authors.lastname: Frijlink
authors.forename: K
authors.initials: K
authors.lastname: Van der Voort Maarschalk
mesh_terms: D000465:Algorithms; D002482:Cellulose / Q000737:chemistry*; D004304:Dosage Forms; D065347:Hypromellose Derivatives; D007091:Image Processing, Computer-Assisted; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D018613:Microscopy, Confocal; D015233:Models, Statistical; D010316:Particle Size; D016062:Porosity; D013678:Technology, Pharmaceutical / Q000379:methods*; D013997:Time Factors
chemical_list: D004304:Dosage Forms; D065347:Hypromellose Derivatives; D002482:Cellulose; D008747:Methylcellulose; C109691:microcrystalline cellulose