猫血浆中莫昔克丁LC-MS/MS检测方法的建立OA

To investigate the pharmacokinetics of compound moxidectin(Moxi)drops in cats,a liquid chromatography-tandem mass spec-trometry(LC-MS/MS)method was developed for the determination of Moxi in cat plasma using Moxi-D3 as the internal standard.Acetoni-trile was used as the extraction solvent.The samples were processed by ultrasonication in a water bath,and the extract was concentrated to dryness.Finally,the residue was reconstituted and analyzed by LC-MS/MS,with quantification performed using the internal standard meth-od.The results showed that the cat plasma matrix did not interfere with the quantitative determination of Moxi.The method exhibited high sen-sitivity,with a limit of detection(LOD)of 0.5 ng/mL and a limit of quantification(LOQ)of 1 ng/mL.The Matrix effects were negligible,hence,a standard curve was prepared with solvent standard solution,and the linearity of Moxi was good in the range of 1 to 120 ng/mL(R2＞0.99).The intra-batch and inter-batch accuracy ranged from 90.15%to 114.81%and 101.32%to 104.10%at different concentration lev-els of spiked samples,respectively.The coefficients of variation(CV)of intra-batch and inter-batch samples were less than 11%.The standard stock and working solutions stayed stable for 9 and 2 months at-18℃,respectively.The spiked samples with different concentra-tions were stable after 6 months of freezing and storage at-18℃,and still stable after repeated freezing and thawing.The processed solutions of the spiked samples remained stable at 4℃for 72 h.These results indicated that the proposed method had good specificity,high sensitivi-ty,stability and reliability,and could be used for the pharmacokinetics study of the compound moxidectin drops in cats.