Pharmacokinetic characteristics of danofloxacin in green sea (Chelonia mydas) and hawksbill sea (Eretmochelys imbricata) turtles.

To date, the number of green sea and hawksbill sea turtles is in decline due to environmental, anthropogenic, and pathological factors. The present study described the pharmacokinetic characteristics of danofloxacin (DNX) in green sea and hawksbill sea turtles, following single intravenous (i.v.) and intramuscular (i.m.) administrations at single dosages of 6 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 168 h. DNX in the harvested plasma was cleaned up using liquid-liquid extraction and analyzed using a validated high-performance liquid chromatography method with fluorescence detection. The pharmacokinetic analysis was performed using a non-compartmental approach. DNX was quantifiable from 5 min to 168 h after i.v. and i.m. administrations at an identical dosage in both turtle types. No statistical differences were found in the pharmacokinetic parameters between green sea and hawksbill sea turtles. The long elimination half-life value of DNX obtained in green sea (35 h) and hawksbill sea (30.21 h) turtles was consistent with the quite large volume of distribution and the slow clearance rate. The high values of absolute bioavailability (87%-94%) should be advantageous for clinical use of DNX in sea turtles. According to the pharmacokinetic-pharmacodynamic surrogate (AUC 0-24 /MIC > 125), DNX is predicted to have antibacterial success for disease caused by bacteria with MIC < 0.04 µg/ml.