Doxorubicin encapsulation and diffusional release from stable, polymeric, hydrogel nanoparticles

We have recently described the preparation of stable, polymeric nanoparticles, composed of poly(ethylene glycol) and poloxamer 407 (Pluronic (R) F127), prepared via inverse emulsion photopolymerization. In the present study we report on the performance of this novel colloidal system as a controlled delivery system for small hydrophobic drugs. Successful encapsulation of doxorubicin occurred through hydrophobic interactions, taking advantage of particle nanoarchitecture. Loadings of up to 8.7 wt.% were achieved with a reproducible, fast, solvent evaporation procedure. In vitro drug release, monitored by fluorescence spectrometry and HPLC, revealed a minor burst (approximately 10% at 37 degrees C) and sustained, diffusional release for over 1 week; furthermore, drug encapsulation significantly delayed doxorubicin degradation kinetics. (c) 2006 Published by Elsevier B.V.