Abstract: Objective To establish a sensitive and specific LC-MS/MS method for determination of Moxifloxacin Hydrochloride in Beagle dog plasma and to evaluate the pharmacokinetic characteristic in dog. Method The concentration of Moxifloxacin Hydrochloride was determined by LC-MS/MS with XTerra@MS C18 column (5μm, 2.1mm×150mm). The mobile phase consisted of methanol-water (50:50, v/v) with the flow rate of 0.2 ml/min. The injection volume was 10 μl. Ions of moxifloxacin and Ciprofloxacin were m/z 402.1→m/z 384.3 (F=120V, CE= 25), m/z 332.2→m/z 314.2(135V, CE=20). Results Standard calibration graph for Moxifloxacin Hydrochloride was linear over a curve range of 10μg/L -2000μg/L (R2>0.99) and the lower limit of quantification was 10 μg/L using a plasma sample of 100μL. The intra-day and inter-day precision (RSD) were in line with analysis of the biological samples. RSD were less than 11.6%, the extraction recoveries were greater than 80%. The concentration-time curves of Moxifloxacin Hydrochloride were best fitted to a two compartment model. The main pharmacokinetic parameters of t1/2, tmax, AUC0–t, AUC0–∞ and CL were 10.7h, 2.1h, 3943μg/L?h, 4177μg/L?h and 10.5L/h?kg respectively. Conclusion The analysis method was specific and suitable for the determination of Moxifloxacin Hydrochloride in Beagle dog plasma and to study the pharmacokinetic character.

Key words: Moxifloxacin Hydrochloride, LC-MS/MS, Beagle dog, Pharmacokinetics