Nanocapsule-coated microparticles prepared in one step : characterization and in vitro drug release profiles evaluation

The aim of this work was to prepare and characterize spray-dried nanocapsule-coated microparticles obtained in one step, using indomethacin as a hydrophobic drug model and poly(ε-caprolactone) or Eudragit® RS100, as polymers. Nanocapsule-coated microparticles showed micrometric mean sizes (10 - 15 µm) and a reduced surface area (75 – 85 m2g-1) compared to the raw material (214 m2g-1). Microparticles coated with Eudragit® RS100-nanocapsules showed a better control of the drug release. The release profiles fit to the monoexponetial model and to the Power Law. The mechanism of the indomethacin release from the microparticles is non-Fickian and depends on the particles desagglomeration