Ischemic stroke is a typical cerebrovascular illness with high morbidity and mortality worldwide. Nevertheless, strategies for the prevention and treatment of cerebral ischemia/reperfusion injury (CIRI) are limited. Gallic acid (GA) is a plant polyphenol that has been used against CIRI. However, the pharmacokinetic (PK) properties of GA, such as its low absorption, poor bioavailability, and quick elimination, have negative effects on its application. To strengthen its effectiveness, a delivery system of GA-loaded o-carboxymethyl chitosan nanoparticles (GA-NPs) was synthesized in our study. In PKs study, GA-NPs apparently increases the area under the curve of plasma concentration-time and prolonged half-life of GA. Then, we measured the in vitro and in vivo effects of the GA-NPs in the oxygen glucose deprivation model and the middle cerebral artery occlusion model. The results from our pharmacodynamic studies, including assessment of neurological deficit, cerebral infarction, levels of inflammation, and oxidative stress, showed that GA-NPs possess better neuroprotection compared with GA. In conclusion, GA-NPs may be used as an efficacious delivery vehicle for GA in the treatment of CIRI. [ABSTRACT FROM AUTHOR]