Determination of Effective Constituents in Imported Novel Coronavirus Specific Drugs by High Performance Liquid Chromatography Tandem Mass Spectrometry

In order to ensure the quality of imported novel coronavirus specific drugs, the method mentioned by the title was proposed. The sample (about 0.600 g) was dissolved in 15 mL of 50% (volume fraction, the same below) methanol solution by ultrasound for 20 min, and made its volume up to 25 mL. 10 mL of the above solution was centrifuged, then 100 μL of the supernatant was taken, and made its volume up to 100 mL with 50% methanol solution. The obtained solution was separated on ZORBAX Eclipse XDB-C₁₈ column, using a mixture of methanol and 0.1%(volume fraction) trichloroacetic acid solution at different volume ratios as mobile phase for gradient elution. As shown by the results, linear relationships between values of the corresponding peak area and mass concentration of nirmatrelvir and ritonavir were found in the range of 2-200 μg·L^-1, with lower limits of determination (10S/N) of 0.85 μg·L^-1 and 0.63 μg·L^-1, respectively. Test for recovery was made by the standard addition method, giving the results in the range of 92.5%-115%, with RSDs (n=6) of the determined values less than 8.0%. This method was used for the analysis of 30 batches of actual samples, and the effective constituents of nirmatrelvir and ritonavir were detected in only 9 samples.