Pharmacokinetics, plasma protein binding and bioavailability of Ketoprofen in Pekin ducks after different routes of administration

1. Although the anti-inflammatory drug Ketoprofen has been used in ducks, there has been no research on its pharmacokinetics. This study examined the disposition kinetics and bioavailability of Ketoprofen in Pekin ducks after intravenous (IV), intramuscular (IM) and oral administration for the first time. 2. A total of 18 ducks were split into three equal groups (n = 6) and were given a single dose of Ketoprofen (5 mg/kg) via IV, IM or oral routes. Blood samples were collected at 16 different time points up to 24 h post‐administration to determine the change in Ketoprofen plasma concentration over time by high-performance liquid chromatography with ultraviolet detection. 3. Following IV injection, total clearance, volume of distribution at steady state and elimination half‐life were 0.31 l/h/kg, 0.32 l/kg and 0.95 h, respectively. Following IM and oral administrations, peak plasma concentrations of 13.82 and 6.76 μg/ml were attained at 0.34 and 0.48 h, respectively. Bioavailability was 106 and 63% for IM and oral route, respectively, and average plasma protein binding was 98.8 ± 2.4%. 4. Ketoprofen showed small volume of distribution and rapid elimination in Pekin ducks. The IM injection resulted in higher plasma concentration and bioavailability than oral administration. This information contributes to the use of Ketoprofen in ducks in an appropriate dosage regimen, but efficacy needs to be demonstrated in experimental inflammation models.