Study on Pharmacokinetics and Residues of Ofloxacin in Common Carp (Cyprinus Carpio)

The paper reported that the oral administration of a single dose of ofloxacin (20mg/kg b.w) carp in vivo pharmacokinetics and skin, muscle, liver and pancreas tissue residues. Were taken before and after administration of plasma and various tissues ofloxacin in plasma and tissue concentrations were measured by reversed-phase high-performance liquid chromatography, mobile phase: methanol-0.05mol / L potassium dihydrogen phosphate buffer -0.5mol / L the four-butylammonium bromide (v / v / v = 10:90:4), with 86% phosphate adjusted pH 3.0, Hypersil-C ₁₈ column (150 × 4.6mm, 5μm), a flow rate of 1.0ml/min, UV detector, wavelength 294 nm, sample treatment: take homogeneous samples, plus pH7.0 phosphate buffered saline, and then extracted with dichloromethane, the organic phase was dried with nitrogen with mobile phase, and the residue was dissolved, n-hexane, fat 3 times, centrifuged back injector 20μl. The sample minimum detection limit for plasma ofloxacin 0.05μg/ml (g), under these conditions, a good linear relationship in the concentration range of 0.1 ~ 25μg/mL curve equation: S = 65709C-1177.4 (r = 0.9997), tissue ofloxacin 0.1 ~~ 10μg / g linear relationship good, hepatopancreas curve equation: S = 63233C-4291 (r = 0.9999), the the muscle curve equation: S = 58701C-4828.3 (r = 0.9998), Skin curve equation: S = 64754C-2924 (r = 0.9996). The recovery, days and day coefficient of variation to meet the requirements. The test results showed that the drug when data are consistent with the open mouth filling 20mg/kg body weight single dose absorption two-compartment model the pharmacokinetic equation: C = 2.834e ^{-0.0286t 50.234e < sup>-2.314t -53.258e -2.901t , the main pharmacokinetic parameters: the apparent volume of distribution (Vd / F) 5.79L/Kg, concentration - time curve The area (AUC) for 120.850μg · h / ml, the absorption half-life (t _{1 / (2ka)} ) as 0.239h, the distribution half-life (t _{1 / (2α)} ) 0.299h, the elimination half-life (t _{1 / (2β)} ) for 24.273h. High performance liquid chromatography determination of ofloxacin residues of carp skin, muscle, liver, pancreas and other tissues, after to give carp oral administration a single dose of 20mg/kg body weight intervals 1, 3, 5, 7, nine days each killed five, nine days after administration of the drug in each tissue residues were lower than 0.08μg / g ofloxacin could be detected in the skin, muscle and hepatopancreas The results showed that ofloxacin slow elimination in carp, residual period longer withdrawal period of not less than nine days.}