Study On The Pharmacokinetics And Residues In The Milk Of Ciprofloxacin Hydrochloride In Cows Suffered From Endometritis Following Single-intrauterine Administration

The pharmacokinetics and residues of ciprofloxacin hydrochloride in the milk were investigated in 5 cows suffered from endometritis following single-intrauterine administration at the dosage of 2.5 per cow. Blood and milk were sampled at different intervals after administration and ciprofloxacin hydrochloride concentrations were determined by RP-HPLC method with a fluorescent detector. Difloxacin was used as intra-standard. The concentration-time data were analyzed with MCPKP program. The ciprofloxacin hydrochloride concentration-time data were fitted to a two-compartment open model with first order absorption in two cows suffered from endometritis after single-intrauterus. The main pharmacokinetics parameters were as follow: T1/2 1.26h, t1/2 10h AUC 28.336 mg/I h, 0.3571b-1 . The ciprofloxacin hydrochloride concentration-time data were fitted to a three-compartment open model with non-absorption in other three cows. The main pharmacokinetics parameters were as follow: T1/2 0.916h, T1/2 49.20h, AUC 7.6296 mg/1 h,Cl 1.582 I/kg h, P 0.642h-1 Milk ciprofloxacin pharmacokinetic parameters were calculated using a one-compartment open model with first order absorption. The main pharmacokinetics parameters were as follow: Ka 0.09125 h-1 , Tmax 19.17h,Cmax 0.01825ug/ml, AUC1.032mg/l h, T1/2Ka, 8.25h, T1/2k 24.64h. The results showed that ciprofloxaxin hydrochloride was absorbed fast and distributed extensively, but it was eliminated slowly in the milk after single-intrauterine administration,60 hours after its administration, the concentration of its residues was 0.00325 0.0015 g/ml and the milk abandon time was 4 days.