Studies On Pharmacokinetics And Tissue Distribution Of Pefloxacin Mesylate In Partridge Chicken

Background: Pefloxacin(Pefloxacin) is the quinolone derivative of methyl-4-piperazine. And it is a high-efficient, low toxic and broad-spectrum antibiotics,characterized by fast absorption, good bioavailability, high drug concentrations of tissues,wide distribution in vivo and long maintained time. Its clinical application mainly focus on mesylating form. In vivo, its antibacterial activity to gram-negative bacterium is similar to the third-generation cephalosporins and new aminoglycosides. Besides, it also have some antibacterial effect to chlamydia, mycoplasma and some gram-positive bacteria.Pefloxacine has made a good effect on treating serious infectious diseases caused by common bacteria and mycoplasma in clinic. Besides, it can break through the blood brain barrier effectively and without cross-resistance with other antibiotics. Last several years,more and more pefloxacin mesylate were applicated in veterinary clinic. Consequently, it has a wide perspective. Whereas, it is still a blank when it comes to the pharmacokinetics of pefloxacin mesylate and tissue distribution of partridge chicken in vivo. And pharmacokinetics is studying on the blood concentration changes over time in animals.Therefore, it is meaningful for guiding the application of mesylate pefloxacin if we make a good research on pharmacokinetic of pefloxacin mesylate, make a scientific and reasonable mode of administration and dosage. Currently, the studies of pefloxacin mesylate in pharmacokinetic mainly focused on people, dogs, goats, but the report of pharmacokinetic in poultry have not seen yet. This experiment can give a reference for the clinical use of pefloxacin mesylate by studying the pharmacokinetics mesylate pefloxacin in partridge chicken and clarifying its changing rules.Objective: In order to better understand the absorption, distribution metabolism and elimination of mesylate pefloxacine in healthy partridge chickens, we established a method for detecting its pharmacokinetic process in MaJi by HPLC. And providing a reference for its rational use in the process of disease prevention and control cilnically by studying on its pharmacokinetic in partridge chicken.Methods: The medicine was given orally gavage to partridge chickens and collect venous blood under the wings at different time points after administration. And plasma samples collected for testing by HPLC with the purpose to research the pharmacokinetic characteristics of pefloxacin mesylate in partridge chicken.The plasma samples were treated with methanol liquid-liquid extraction, and choosed enrofloxacin as the internal standard. HPLC is Shimadzu LC-10 A, chromatographic column is shimadzu ODS-C18(250×4.6 mm, 5 μm), detective wavelength is 276 nm, mobile phase is0.025 mol/L phosphoric acid solution(triethylamine adjusted pH 3.1 ± 0.1)- acetonitrile(80:20, V/V), the flow rate is 1 mL/min, the injection volume is detected with 20 μL of chromatographic conditions. The retention time of pefloxacin mesylate and enrofloxacin were 6.1 min and 8.0 min respectively.Results: By the study of pharmacokinetic found that the pharmacokinetic parameters generation of partridge chicken with aminophylline oral given 20 mg/kg was showed as follow.The Cmax of peak plasma concentration was( 6886.7 ± 444.6) μg / mL, Tmax to peak was 2 h, elimination half-life t1/2 was( 7.03 ± 0.17) h, the elimination rate constant was 0.10 h-1, AUC0-t was(64333.4 ± 2309.0) ng·h·m L-1, AUC0â†'∞ was(66507.3 ± 2428.7)ng·h·m L-1,the mean residence time was(7.67 ± 0.18) h, clearance CLtot was(5.0 ± 0.19)ng·h·m L-1, the apparent distribution volume Vz was( 3.05 ± 0.11) L·kg-1. Tissue distribution studies show that partridge chicken after oral pefloxacin mesylate 20 mg/kg, the highest concentration of the drug is in the liver, the peak concentration Cmax was(16800 ± 1914.4)ng / m L, the peak time Tmax was 1 h, eliminate half-life t1/2 was(33.70 ± 8.80) h. Followed by the liver is the kidney, the peak concentration Cmax was(15980.0 ± 5856.4) ng/m L, the peak time Tmax was 1 h, the elimination half-life t1/2 was(17.30 ± 3.9) h. In the lungs, leg muscle,brain, bone marrow, pancreas could be detected pefloxacin mesylate, while the concentration was very low, but the durationthe was long, likely to cause accumulation. In the chest, any concentration of pefloxacin mesylate was not detected.