Synthesis and characterization of crosslinked microparticles for drug delivery

Crosslinked chitosan and poly(hydroxypropyl methacrylate) microparticles co ntaining a hydrophilic bioactive material, hydroquinone, were synthesized b y suspension crosslinking and suspension polymerization, respectively and w ere extensively characterized. The produced microparticles had a spherical geometry and a smooth surface. The release rate of hydroquinone from the mi croparticles could be adjusted by varying the degree of polymer crosslinkin g as well as the initial polymer concentration. The degree of polymer swell ing of the PHPMA microparticles could be properly modified by suitable adju stment of the degree of polymer crosslinking and of the composition of the solvent.