Determination of Related Substances in Metamizole Sodium Injection / 中国药师

ABSTRACT

Objective:To establish an HPLC method to determine the related substances in metamizole sodium injection. Meth-odsThe separation was performed on an Xtimate C18(250 mm×4.6 mm,5 μm) column,and phosphate buffer(dissolving 6.0 g so-dium dihydrogen phosphate and 1 ml triethylamine in 1 000 ml water, adjusting pH to 7.0 with sodium hydroxide solution)-methanol (75 25) as the mobile phase,and the flow rate was 1.0 ml·min-1. The detection wavelength was 254 nm,the column temperature was 30 ℃,and the injection volume was 5 μl. Results:The adjuvants,metamizole sodium and their related substances could be sepa-rated well under the chromatographic conditions. A total of 2 known impurities(impurity C and impurity E) and 4 unknown impurities were detected out. The amount of impurity C was between 2.87% and 5.82%, the amounts of impurity E and 4 unknown impurities were all less than 0.1%. Conclusion:The method is simple,accurate and specific, and can be used for the quality control of met-amizole sodium injection.