Disposition kinetics of meloxicam in green sea turtles (Chelonia mydas) after intravenous and intramuscular administrations.

The pharmacokinetics were described of meloxicam (MLX) in green sea turtles (Chelonia mydas), following a single intravenous (i.v.) and intramuscular (i.m.) administrations at one of two dosages of 0.1 or 0.2 mg/kg body weight (b.w.). The sample of 20 green sea turtles was divided into four groups (n = 5) using a randomization procedure according to a parallel study design. Blood samples were collected at pre-assigned times up to 168 h. MLX in the plasma was cleaned-up and quantified using a validated high-performance liquid chromatography method with UV detection. The concentration of MLX in the experimental green sea turtles with respect to time was pharmacokinetically analyzed using a non-compartment model. MLX plasma concentrations were quantifiable for up to 72 and 120 h after i.v. at dosages of 0.1 and 0.2 mg/kg b.w., respectively, whereas it was measurable for up to 168 h after i.m. administration at both dosages. The long elimination half-life value of MLX (28 h) obtained in green sea turtles after i.v. administration was consistent with the quite slow clearance rate for both dosages. The average maximum concentration (Cmax ) values of MLX were 1.05 µg/mL and 4.26 µg/mL at dosages of 0.1 and 0.2 mg/kg b.w., respectively, with their elimination half-life values being 37.26 h and 30.64 h, respectively, after i.m. administrations. The absolute i.m. bioavailability was approximately 110%. These results suggested that i.m. administration of MLX at a dosage of 0.2 mg/kg b.w. was likely to be effective for clinical use in green sea turtles (Chelonia mydas). However, further studies are needed to determine the pharmacodynamic properties and clinical efficacy of MLX for the treatment of inflammatory disease after single and multiple dosages.

Pharmacokinetic characteristics of florfenicol in green sea turtles (Chelonia mydas) and hawksbill sea turtles (Eretmochelys imbricata) after intramuscular administration.

The pharmacokinetics of florfenicol (FFC) in green sea and hawksbill sea turtles were evaluated following intramuscular (i.m.) administration at two different dosages of 20 or 30 mg/kg body weight (b.w.). This study (longitudinal design) used 5 green sea and 5 hawksbill sea turtles for the two dosages. Blood samples were collected at assigned times up to 168 h. FFC plasma samples were analyzed using validated high-performance liquid chromatography equipped with diode array detection. The pharmacokinetic analysis was performed using a non-compartment approach. The FFC plasma concentrations increased with the dosage. The elimination half-life was similar between the treatment groups (range 19-25 h), as well as the plasma protein binding (range 18.59%-20.65%). According to the surrogate PK/PD parameter (T > MIC, 2 µg/mL), the 20 and 30 mg/kg dosing rates should be effective doses for susceptible bacterial infections in green sea and hawksbill sea turtles.

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 (AUC0-24 /MIC > 125), DNX is predicted to have antibacterial success for disease caused by bacteria with MIC < 0.04 µg/ml.

Pharmacokinetics of tolfenamic acid in green sea turtles (Chelonia mydas) after intravenous and intramuscular administration.

The present study aimed to evaluate the pharmacokinetic features of tolfenamic acid (TA) in green sea turtles, Chelonia mydas. Green sea turtles were administered single either intravenous (i.v.) or intramuscular (i.m.) injection of TA, at a dose of 4 mg/kg body weight (b.w.). Blood samples were collected at preassigned times up to 168 hr. The plasma concentrations of TA were measured using a validated liquid chromatography tandem mass spectrometry method. Tolfenamic acid plasma concentrations were quantifiable for up to 168 hr after i.v. and i.m. administration. The concentration of TA in the experimental green sea turtles with respect to time was pharmacokinetically analyzed using a noncompartment model. The Cmax values of TA were 55.01 ± 8.34 µg/ml following i.m. administration. The elimination half-life values were 32.76 ± 4.68 hr and 53.69 ± 3.38 hr after i.v. and i.m. administration, respectively. The absolute i.m. bioavailability was 72.02 ± 10.23%, and the average binding percentage of TA to plasma protein was 19.43 ± 6.75%. Based on the pharmacokinetic data, the i.m. administration of TA at a dosage of 4 mg/kg b.w. might be sufficient to produce a long-lasting anti-inflammatory effect (7 days) for green sea turtles. However, further studies are needed to determine the clinical efficacy of TA for treatment of inflammatory disease after single and multiple dosages.