Determination of Related Substances of Cetrorelix Acetate Injection by UPLC

OBJECTIVE To establish an UPLC method for determination of related substances of Cetrorelix Acetate injection. METHODS The separation was performed on ACQUITY UPLC CSHTMC₁₈ column(2.1 mm×150 mm, 1.7 μm), 0.05 mol·L^-1 sodium perchlorate solution(adjust the pH with phosphoric acid to 2.0) was used as mobile phase A, and 0.05 mol·L^-1 sodium perchlorate solution-acetonitrile(30︰70)(adjust the pH with phosphoric acid to 2.0) was used as mobile phase B, with a gradient elution. Flow rate was 0.2 mL·min^-1, the detection wavelength was 226 nm and sample volume was 1 μL. RESULTS The linear ranges of impurity A, B, C, D, E and F were 0.127 8-6.390 4, 0.124 4-6.221 3, 0.126 8-6.340 8, 0.120 5-6.025 6, 0.120 9-6.047 3, 0.127 7-6.389 4 μg·mL^-1, respectively. The limits of detection of each impurities was about 0.04 ng. The limits of quantitation of impurity B, D, E were about 0.12 ng, that of impurity A, C, F were about 0.13 ng. The average recoveries were 97.4%, 95.2%, 101.5%, 105.3%, 100.7%, 97.4%, respectively. RSDs were 1.7%, 3.0%, 3.8%, 2.4%, 0.8%, 2.8%(n=9), respectively. CONCLUSION The method is rapid, simple, accurate and specific and can be used for the quantitative study on related substances in Cetrorelix Acetate for injection.