Visualization and quantification of polymer distribution in microcapsules by confocal laser scanning microscopy (CLSM)

Int J Pharm. 2000 Mar 10;196(2):223-6. doi: 10.1016/s0378-5173(99)00427-5.

Abstract

Confocal laser scanning microscopy (CLSM) was employed in order to characterize microcapsules. Microcapsules were prepared by complex coacervation: gelatin and arabic gum were labelled with fluorescent markers. In the capsule wall a homogeneous distribution for both gelatin and arabic gum throughout the capsule wall was depicted. By the use of CLSM and a computational image analysis the quantification of the labelled polymer in the wall material was possible. Adding fluorescently labelled casein as a macromolecular model compound to the coacervation process, a gradiental distribution in the wall material was observed with highest concentration of casein at the oil-wall interface. The influence of casein concentration on its deposition behaviour in the capsule wall was imaged successfully and thereafter quantified by computational image analysis.

MeSH terms

  • Capsules / chemistry*
  • Caseins / chemistry
  • Drug Compounding
  • Emulsions
  • Fluorescein-5-isothiocyanate
  • Fluorescent Dyes
  • Gelatin / chemistry
  • Gum Arabic / chemistry
  • Image Processing, Computer-Assisted
  • Microscopy, Confocal*
  • Polymers / chemistry*

Substances

  • Capsules
  • Caseins
  • Emulsions
  • Fluorescent Dyes
  • Polymers
  • Gum Arabic
  • Gelatin
  • Fluorescein-5-isothiocyanate