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(epsilon-caprolactone) or Eudragit (R) RS100, as polymers. Nanocapsule-coated microparticles showed micrometric mean sizes (10-15 mu m) and a reduced surface area (75 - 85 m(2)g(-1)) compared to the raw material (214 m(2)g(-1)). Microparticles coated with Eudragit (R) 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.