人血浆中氧氟沙星的HPLC测定及药代动力学研究

建立了人血浆中氧氟沙星含量的HPLC测定方法,以Spherisorb C18柱分离,流动相组成为甲醇-0.01mol/L磷酸盐缓冲液-0.5mol/L四丁基溴化铵(35:65:4,pH 2.5),流速为1.0 ml/min,在UV 294nm处测定。样品采用甲醇沉淀蛋白后,混旋、离心,吸取上清液在75℃下用氮气流吹干后,以0.4ml流动相稀释进样。采用内标法定量,在0.5～4.0μg/ml的浓度范围内呈线性关系,r=0.9999。最小检测浓度为20ng/ml。用本法对10名分别服用进口和国产氧氟沙星片剂的健康志愿者进行了血药浓度测定,取得了满意的结果,并对其药代动力学参数及生物利用度进行了研究。

DETERMINATION OF OFLOXACIN IN HUMAN PLAS MA AND STUDIES OF ITS PHARMACOKINETICS USING HPLC METHOD

Ofloxacin is a new broad-spectrum oral bactericidal antimicrobial agent. Its primary effect is the inhibition of bacterial DNA gyrase. This paper describes the development of a simple method for its determination using HPLC with UV detection. We used a Waters liquid chromatograph equipped with a Model 490 E multi-wavelength detector, a Model 510 pump and a U6K injector. The separation was performed on a Spherisorb C18 column (200 mm x 4.6 mm ID, 5 microns) with a mobile phase of methanol-0.01 mol/L phosphate buffer-0.5 mol/L tetrabutylammonium bromide (35:65:4, pH 2.50). The flow-rate was 1.0 ml/min and detection was at 294 nm. A specimen (0.2 ml) was spiked with the internal standard (norfloxacin) and deproteinized by adding 1.0 ml methanol. The precipitated mixture was shaken and then centrifuged at 3000 x g for 10 min, the supernatant was evaporated at 75 degrees C under a nitrogen stream. The residue was taken up with 0.4 ml of the mobile phase and 50 microliters aliquots were injected into the system. The minimal detectable concentration in plasma is 20 ng/ml. There is a linear relationship between the peak area ratio over the range of 0.5-4.0 micrograms/ml with r = 0.9999. The method has been applied to assay ofloxacin concentration in human plasma. The pharmacokinetic characteristics were studied.