title: Study of the theophylline content of single coated particles by gas chromatography/mass spectrometry.
abstract: The aim of the present study was to determine by gas chromatography/mass spectrometry (GC/MS) the content uniformity of single theophylline microcapsules of different particle size ranges. Microencapsulation was carried out in a laboratory fluidized bed system using Eudragit L30D aqueous dispersion. Scanning electron microscopy was applied for the characterization of the surface morphology of the prepared theophylline microcapsules of two different particle size ranges. The theophylline content of single particles was determined by GC/MS analysis. It was found that the particle size of microcapsules greatly influenced their theophylline content. The GC/MS analysis was successully applied to indicate the changes in the content uniformity and thus the interparticular costing distribution of single theophylline microcapsules in the presence of several excipients.
authors.affiliation: Pharmaceutical Institute, Semmelweis University, Budapest, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Budavári
authors.forename: R
authors.initials: R
authors.lastname: Zeikó
authors.forename: S
authors.initials: S
authors.lastname: Marton
authors.forename: I
authors.initials: I
authors.lastname: Rácz
mesh_terms: D002138:Calibration; D002214:Capsules; D005079:Excipients; D008401:Gas Chromatography-Mass Spectrometry; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D013806:Theophylline / Q000032:analysis*
chemical_list: D002214:Capsules; D005079:Excipients; D013806:Theophylline