Preparation and dissolution pattern of Eudragit RS microcapsules containing ketoprofen.

Abstract
Microencapsulation of ketoprofen using Eudragit RS, which is a copolymer synthesized from acrylic and methacrylic acid esters with a low content of quaternary ammonium groups, was investigated. The preparation is based on dispersion of acetone containing the drug in liquid paraffin. Aluminium tristearate was used as an additive for the preparation of microcapsules. Good reproducibility in microcapsule preparation was observed. The microcapsules obtained were uniform and free-flowing particles. The dissolution rates of ketoprofen from these microcapsules were considerably decreased as compared with that from ketoprofen powder.