ABSTRACT
Objective To improve and establish an RP-HPLC method for the determination of related substances of piracetam and its injection. Methods Using thermo syncronis C18(4.6 mm ×250 mm,5μm)chromatographic column, mobile phase was acetonitrile-phosphate buffer (adjust pH of 1.0 g/L potassium hydrogen phosphate solution to 6.0 with phosphoric acid), gradient elution with initial mobile phase 5% acetonitrile.The flow rate was 1 mL/min, detected at 205 nm.Five calibration factors of the known impurities were separately measured.the related substances were determined using main component self-compare with calibration factor.Results Piracetam and their related substances were well separated.The calibration curves of five known impurity A~E were linear within the concentration range measured.The average recoveries were 99.46%,98.21%,97.22%,100.23% and 97.58%, respectively(n=9), RSDs of the average recoveries were lower than 2.0%.The calibration factors of five known impurity A ~E were 1.1, 1.4,1.5,0.8, 1.4, respectively.Conclusion The method can be used to determine the related substances in piracetam and its injection.The related substances can be determined accurately using main component self-compare with calibration factor.