title: Effect of particle size and coating level on the diffuse reflectance of wax matrices.
abstract: The aim of this study was to examine the influence of particle size and extent of coating on the diffuse-reflectance spectra of wax matrices containing embedded potassium chloride. Near-infrared spectroscopy was used to analyse the diffuse-reflectance characteristics of the prepared multi-particulate matrices without destructive sample preparation. A 2-factor, 3-level face-centred central composite design was selected to construct a second-order polynomial model which described the effect of particle size and amount of coating on the intensity of the diffusely reflected light. A non-linear model was used to demonstrate the effect of the selected parameters on the intensity of the reflected light; good correlation was obtained between experimental and predicted results. The results indicated that the extent of coating and the particle size of the examined systems in the selected particle size-range modified the intensity of the reflected light. It can be concluded that near-infrared spectroscopy is a sensitive means of measuring not only the particle size of powders (substrates and their mixtures), but also that of coated multi-particulate systems.
authors.affiliation: Pharmaceutical Institute, Semmelweis University of Medicine, Budapest, Hungary.
authors.forename: J
authors.initials: J
authors.lastname: Dredán
authors.forename: R
authors.initials: R
authors.lastname: Zelkó
authors.forename: I
authors.initials: I
authors.lastname: Antal
authors.forename: E
authors.initials: E
authors.lastname: Bihari
authors.forename: I
authors.initials: I
authors.lastname: Rácz
mesh_terms: D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations / Q000737:chemistry*; D007700:Kinetics; D010316:Particle Size; D011189:Potassium Chloride / Q000737:chemistry; D011208:Powders; D019265:Spectroscopy, Near-Infrared; D014885:Waxes / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D011208:Powders; D014885:Waxes; D011189:Potassium Chloride