Patent ID: 8853389

Claim:
A process for refining Cefmetazole sodium, characterized in that, it comprises the steps of: 1) dissolving Cefmetazole sodium-contained raw material in water, and extracting after adding a water-immiscible organic solvent(s) selecting from a group consisting of ethyl acetate, cyclohexane, and a mixture of ethyl acetate and cyclohexane, followed by separating the organic phase containing impurities, to provide a primarily purified Cefmetazole sodium in the aqueous phase; 2) treating by adding an alkoxide of alkali metal or alkaline earth metal into the above aqueous phase, optionally under heating during the treating process, followed by cooling down and filtrating the precipitate to provide a filtrate, which is a secondarily purified Cefmetazole sodium aqueous solution; and 3) adding in the aqueous solution a solvent selecting from a group consisting of ethanol, acetone and a mixture of ethanol and acetone, and recrystallizing by decreasing the temperature until it reaches between room temperature and −5° C., followed by centrifuging and washing the resultant crystals, to provide a thirdly purified Cefmetazole sodium after drying.