The stability of cefuroxime sodium (50mg/mL) in 0.9% sodium chloride injection stored in polypropylene syringes was studied at 25 and 5 deg C by means of a stability-indicating high-performance liquid chromatographic assay method. The concentrations of the drug were directly related to peak heights, and the percent relative standard deviation based on five injections was 0.9. There were at least two products of decomposition that separated from the intact drug. The loss in potency was less than 10% after 2 days of storage at 25 deg C, and the loss in potency was less than 4% after 21 days of storage at 5 deg C. The pH vallue increased from 6.9 to 7.3 when the injection was stored at 25 deg C for 2 days, and the pH value increased from 6.9 to 7.0 when the injection was stored at 5 deg C for 21 days. The drug was not adsorbed onto the syringes. The intensity of the light-yellow color increased with the storage period at 25 deg C, but did not change signiificantly with storage at 5 deg C.