Alpha-phenyl-n-tert-butyl nitrone (PBN) shows its major effect by scavenging free radicals formed in
the ischemia and it has the ability to penetrate through the blood brain barrier easily. The in vivo
stability of PBN is very low and when administered systemically, it has a mean plasma half life of
about three hours. Therefore, formulations which are able to prolong the plasma residence time of
PBN are of major interest, because oxygen radicals are usually continuously formed under pathologi-
cal conditions. In this study, PBN, a nitrone compound having neuroprotective properties, was encap-
sulated in chitosan (CS) and chitosan-poly(ethylene glycol) (CS-PEG) nanoparticles for treatment of
diseases such as stroke, in which sustained free radical production is reported. The nanoparticles
were characterized through particle size determination, zeta potential, encapsulation efficiency, surface
morphology determinations and in vitro release studies. The surface morphologies were evaluated by
transmission electron microscopy (TEM) and nanoparticles having spherical shapes were character-
ized. The particle size distribution was between
97 nm and
322 nm; and the zeta potentials varied
between
9 mV and
33 mV. Size of the nanoparticle formulations was important for the release of
PBN from nanoparticles. The quantitative determination of PBN has been evaluated by a validated
analytical HPLC method. The presented chitosan-based nanotechnology opens new perspectives for
testing antioxidant activity in vivo.