Pharmacokinetics of flunixin-meglumin following intravenous administration in Angora rabbits

The pharmacokinetics of flunixin-meglumin were determined after intravenous bolus injection at two different doses (1.1 and 2.2 mg/kg body weight) in rabbits. Six healthy adult Angora rabbits were used in the experiment. Blood samples were collected at 10, 20, 30, 45 and 60 min, 2, 4, 6, and 8 h after injection. Concentrations of drug in plasma were determined by HPLC. Pharmacokinetics were described by a two-compartment open model. The area under the curve, contrary to other pharmacokinetic parameters, showed statistically significant differences between the two doses used (P<0.05). The data obtained for the low and high doses were as follows: the elimination half-lives were 1.4 and 1.7 h, the volume of distribution - 0.6 and 0.8 L/kg, and total body clearance - 0.32 and 037 mL/h/kg body weight, respectively. The present study has shown that the pharmacokinetic variables of fluxin-meglumin in Angora rabbits are dose independent in the dose range of 1.1-2.2 mg/kg body weight.