Synercid is a combination of two semisynthetic @entity30658 derivatives, @entity11685 and @entity11686 in 30:70 (w/w) ratio. A rapid and specific high-performance liquid chromatography-mass spectrometry was developed for the determination of @entity11685 and @entity11686 using positive electrospray tandem mass spectrometry (+ESI- @entity15 / @entity15 ). Multiple reaction monitoring transitions at 1023.05>134.34 and 691.87>166.26 were selected for the quantitation of @entity11685 and @entity11686 , respectively. The assay run cycle-time was approximately 2.0 min injection-to-injection. The assay was linear up to concentration of 4000 ng x ml(-1) @entity11685 and 1920 ng x ml(-1) @entity11686 . The lowest limits of quantitation of @entity11685 and @entity11686 were found to be 1000 and 480 ng x ml(-1), respectively. Quantitation was based on peak area measurement of @entity11685 and @entity11686 using weighed linear regression. Linear relationships with correlation coefficients (r>0.99) were automatically computed for both constituents by MASSLYNX quantify program. The ratio of the slopes of the calibration curves of @entity11685 and @entity11686 was found to be 0.425, which matches the nominal ratio composition of the antimicrobial compounds in Synercid. The %RSD ranges were 2.3-4.0% for @entity11686 and 1.3-4.2% for @entity11685 , whereas the %DEV ranges were (-7.5+3.7) and (-1.2+9.1%), respectively, indicating appropriate precision and accuracy. Recoveries of 99.5-103.8% and 97.8-99.0% of @entity11685 and @entity11686 , respectively, were computed from Synercid injection. The described method is recommended for rapid determination of the contents and for tracking the stability and compatibility of @entity11685 and @entity11686 in Synercid injection.

LC- XXXX / @entity15 determination of Synercid injections.

@entity11685 :: ('MESH:C113825', 'Chemical') :: ['quinupristin'] @entity30658 :: ('MESH:D025762', 'Chemical') :: ['pristinamycin'] @entity11686 :: ('MESH:C113826', 'Chemical') :: ['dalfopristin'] @entity15 :: ('MESH:D009103', 'Disease') :: ['MS']
@entity15 :: (MESH:D009103,Disease) :: ['MS']
