Simultaneous Determination of Celecoxib, Dezocine and Dexmedetomidine in Beagle Plasma Using UPLC-MS/MS Method and the Application in Pharmacokinetics

Abstract
Background: An efficient, fast and sensitive ultra high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method for simultaneous determination of celecoxib (CEL), dezocine (DEZ) and dexmedetomidine (DEX) in beagle plasma were established. Methods: The beagle dogs plasmawas precipitated by acetonitrile. The column was Acquity UPLC BEH C18 column and the mobile phase was acetonitrile-formic acid with gradient mode, and the flow rate was set at 0.4 mL/min. Under the positive ion mode, CEL, DEZ, DEX and Midazolam (internal standard, IS) were monitored by multiple reaction monitoring (MRM) as the following mass transition pairs: m/z 381.10→ 282.10 for CEL, m/z 246.20→ 147.00 for DEZ, m/z 201.10→ 94.90 for DEX, and m/z 326.10→ 291.10 for IS. Results: This UPLC-MS/MS method had good linearity for CEL, DEZ and DEX. The RSDs of inter-day and intra-day precision were the values of 0.31– 7.66% and 0.11– 9.63%, respectively; the RE values were from − 6.05% to 10.98%. The extraction recovery was more than 79%, and the matrix effect was around 100%. The RSDs of stability were less than 8.96%. All of them met the acceptance standard of biological analysis method recommended by FDA. Conclusion: This UPLC-MS/MS method is an effective tool for the simultaneous determination of CEL, DEX and DEX, and has been successfully applied to the study of pharmacokinetics in beagle dogs.