Comparison Of Pharmacokinetics Of Danofloxacin In Healthy And Pasteurella Multocida Infected Ducks

Danofloxacin is the third generation of fluoroquinolone antimicrobials which is solely used in veterinary.It shows great merits in treatment of fowl cholera caused by Pasteurella multocida.To study the influence of pathological state caused by pastuerellamultocida infection on pharmacokinetics of danofloxacin,this paper compares the pharmacokinetic parameters of danofloxacin in the serum and lung tissue of healthy ducks and those infected by Pasteurella multocida.The in vitro antibacterial effects of danofloxacin against Pasteurellosis was also studied.The results provide theoretical basis for the treatment of Pasteurella multocida infection and guide the rational use of danofloxacin.First of all,the in vitro efficacy of danofloxacin against Pasteurella multocida showed that the MIC was 0.25 μg/mL,the MBC was 1 μg/mL and the MPC was 3.2 μg/mL.The post antibiotic effect(PAE)was observed in the vitro efficacy of danofloxacin against the Pasteurella multocida.The in vitro static sterilization curve showed that,when the drug concentration was 0.5 μg/mL,an inhibitory effect on bacteria within 24 hours was achieved;when the concentration was higher than 0.5 μg/mL,the drugs have a bactericidal effect.Secondly,the model of ducks infected by Pasteurella multocida is established.1.5×102 CFU/kg b.w bacteria was injected into the muscel of the healthy ducks.Pathological symptoms and clinical symptoms was observed.Pathogen was isolated from the sick duck.Finally,the pharmacokinetics of danofloxacin in health and infected ducks was performed by oral administration(PO)at a single doe of 5mg/kg b.w..The drug concentration in serum samples and lung tissue samples were determined by high performance liquid chromatography(HPLC).The concentration-time data of danofloxacin were analyzed with non-compartmental model using software WinNonlin 5.2.The main pharmacokinetic parameters of danofloxacin in serum of health ducks were Cmax:0.47±0.01 μg/mL,Tmax:3,75±1.53 h,T1/2β:13.24±2.56 h,AUC:5.70± 1.15 μg·h/mL.The main pharmacokinetic parameters of danofloxacin in lung tissue of health ducks is Cmax:9.96±0.13 μg/g,Tmax:4 h,T1/2β:10.31 ±0.43 h,AUC:106.22±3.31 μg h/g.The main pharmacokinetic parameters of danofloxacin in the serum of infected ducks is Cmax:0.38±0.01 μg/mL,Tmax:2.15± 1.18h,T1/2β:17.00±2.70 h,AUC:7.19± 1.21μg ·h/mL.T he main pharmacokinetic parameters of danofloxacin in lung tissue of infected ducks is Cmax:8.93±0.30 μg/g,Tmax:2.75±0.50 h,T1/2β:13.03±0.09 h,AUC:135.37±4.35 μg·h/g.Compared to the healthy ducks,the absorption rate of danofloxacin and the total amount of drug in the body circulating was increased in the infected ducks,but the elimination rate was slower.but is more widespread.Danofloxacin was distributed more widely in infected ducks.