Abstract: A simple, rapid and sensitive HPLC-MS method was developed and validated for determining bezafibrate in rat plasma. Chromatographic separation was achieved on a reversed-phase Gemini C18 at 35 ℃ using acetonitrile, methanol and 0.03% aqueous solution of formic acid(volume ratio 60∶15∶25) as mobile phase at flow rate of 0.3 mL/min. The UV absorption wavelength was set at 235 nm and the injection volume was 5 μL. Under these conditions, the detection was performed with negative electrospray ionization, monitoring the transitions m/z 359.65→273.70 for bezafibrate and m/z 212.95→127.08 for the clofibric acid(internal standard). A good linearity was achieved within the concentration range of 0.073~7.884 mg/L(r=0.9995) for bezafibrate and the mean recovery of samples ranged from 94.3% to 103.1% at three tested concentrations. The intra-day and inter-day precisions(as relative standard deviation) were below 6%. The limit of quantification(LOQ) was 30 μg/L and the limit of detection(LOD) was 9 μg/L. This HPLC-MS method was reproducible and sensitive enough for routine analysis of bezafibrate in human plasma.

Key words: benzafibrate, HPLC&, ndash, MS, rat plasma