Preparation of a controlled release drug delivery system of indomethacin: Effect of process equipment, particle size of indomethacin, and size of the nonpareil seeds

Abstract

Indomethacin pellets (IS) were prepared by spraying a slurry of indomethacin, Eudragit® S-100, dibuty1 sebacate and alcohol onto an appropriate mesh fraction of nonpareil seeds using appropriate processing equipment. Factors affecting this layering process were studied and identified. The average particle diameter and the overall particle size distribution of the indomethacin powder were found to be critical factors influencing the physical properties of the IS pellets. Micronized indomethacin powder, having an average particle diameter of four microns and a particle size distribution ranging from one to thirteen microns, was found to be the optimum for this layering process. Altering the mesh fraction of the starting nonpareil seeds for the layering process was found to greatly affect the release characteristics of the drug from the beadlets. The Wurster column process was found to be better than a fluid-bed granulator process for the manufacture of IS beadlets.