The present invention is directed to nanoparticles comprising crosslinked chitosan and amoxicillin, wherein amoxicillin is entrapped by the crosslinked chitosan. The nanoparticles have an average diameter of 100-600 nm, and the entrapped amoxicillin is at least 5% (w/w) of the total weight nanoparticles. The nanoparticles when orally taken have a longer residence time in the stomach than that of free amoxicillin or microspheres having micron sizes. The present invention also provides a process for preparing the nanoparticles. The present invention further provides a method of treating bacterial infection by orally administering to a subject the nanoparticles of the present invention, in an amount effective to treat bacterial infection.本發明係關於包含交聯聚葡萄胺糖及阿莫西林之奈米粒子,其中藉由該交聯聚葡萄胺糖包覆阿莫西林。該等奈米粒子之平均直徑為100-600nm,且該經包覆阿莫西林為奈米粒子總重量之至少5%(w/w)。當經口服用時,該等奈米粒子在胃中具有比自由阿莫西林或微米尺寸之微粒更長的滯留時間。本發明亦提供一種製備該等奈米粒子之方法。本發明進一步提供一種藉由以有效治療細菌感染之量向個體經口投予本發明之奈米粒子來治療細菌感染的方法。
