Fast and sensitive RP-HPLC-fluorescence method for the quantitative analysis of moxifloxacin in rat plasma and its application to a preclinical pharmacokinetic Study

Abstract

A fast, simple, and sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed and fully validated for the determination of moxifloxacin (MXF) in rat plasma. MXF and gatifloxacin (internal standard, I.S.) were extracted from plasma by single-step protein precipitation with acidified acetonitrile. Chromatographic separation was accomplished in less than 8 min on an Atlantis ® T3 column with 0.4% aqueous triethylamine-methanol-acetonitrile (60:35:5, v/v/v) solution as mobile phase. Detection was achieved by fluorescence (λexcitation = 295 nm, λexcitation = 500 nm), and the calibration curves were found to be linear over the plasma concentration range of 10-2,500 ng mL-1 with a mean correlation coefficient (r) of 0.9946 (n = 6). The intra- And inter-assay imprecision (% CV) was less than 2.4 and 3.3%, respectively, and the accuracy was >90%. The mean extraction recoveries for MXF and I.S. from plasma were 77 and 82%, respectively. The method was also validated for specificity, sensitivity, and stability; all the results were within the acceptable range. The proposed method was then successfully applied to the quantitative analysis of MXF in rat plasma samples, being a valuable and high-throughput assay to support ongoing pharmacokinetic studies on this promising anti-infective agent.