Pharmacokinetic parameters and milk concentrations of ketoprofen after administration as a single intravenous bolus dose to lactating goats.

Six clinically normal lactating does were administered ketoprofen (2.2 mg/kg intravenously (i.v.)). Blood and milk samples were collected prior to and for 24 h after drug administration. Drug concentrations in serum and milk were determined by high performance liquid chromatography. Pharmacokinetic parameters from each goat were combined to obtain mean estimates (mean +/- SD) of half-life of elimination (t1/2beta) of 0.32 +/- 0.14 h, systemic clearance (Cl) of 0.74 +/- 0.12 L/kg x h, and volume of distribution at steady state (V(ss)) of 0.23 +/- 0.051 L/kg. In milk, ketoprofen was unmeasurable by the method employed (level of detection 25 ng/mL) for all samples.