Pharmacokinetics of marbofloxacin after a single oral dose to loggerhead sea turtles (Caretta caretta).

The single-dose disposition kinetics of marbofloxacin (MBX) were determined in clinically healthy loggerhead sea turtles (n=5) after oral (PO) administration of 2 mg kg(-1) bodyweight. Marbofloxacin plasma concentrations were determined by DAD-HPLC (LOD/LOQ 0.015/0.05 microg ml(-1)). Data were subjected to non-compartmental analysis. Following PO administration, marbofloxacin achieved maximum plasma concentrations of 11.66+/-2.53 mg L(-1) at 15.00+/-3.00 h. The absence of general adverse reactions in the turtles of the study, and the favourable pharmacokinetic properties (long half-life and high maximum plasma concentration) of MBX administered PO at the single-dose of 2 mg kg(-1) suggest the possibility of its safe and effective clinical use in loggerhead sea turtles.

Polychlorinated biphenyls and organochlorine pesticide levels in tissues of Caretta caretta from the Adriatic Sea.

We detected concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs) in the liver, muscle, and fat of 11 loggerhead sea turtles Caretta caretta from the central and southern Adriatic Sea. All samples contained PCBs at various concentrations, with Congener 138 (28%), 153 (27%), and 180 (32%) dominating the congener composition of the tissues. The dioxin-like congener (118, 13%) was detected in all tissues analyzed. The lower-chlorinated PCBs were not detected. The average of the total PCB concentrations, expressed in nanograms per gram wet weight, was 459.6 ng g(-1) in fat, 82.9 ng g(-1) in liver, and 5.8 ng g(-1) in muscle. Among 13 organochlorine pesticides for which analyses were conducted, 4 were detected: p,p'-DDE (57%); p,p'-DDD (16%); and p,p'-DDT and o,p'-DDT (27%). Spatial differences were found among OC concentrations in loggerheads from the central and southern Adriatic Sea. The only samples containing detectable concentrations of p,p'-DDT and o,p'-DDT were from the southern area.

Pharmacokinetics and mammary elimination of imidocarb in sheep and goats.

The pharmacokinetics and mammary excretion of imidocarb dipropionate, a therapeutic/prophylactic agent against a variety of tick-borne hemoparasitic diseases in domestic animals, have been investigated in sheep and goats. A commercial formulation of imidocarb di-propionate was injected i.m. at a single dose of 3 mg/kg of body weight in 7 mature lactating ewes and 8 lactating does in good health. Blood samples were collected for 48 h after administration and milk samples were collected every 12 h for 10 d. A weak cation-exchange solid-phase procedure was used to remove imidocarb from plasma. A hexane/isoamyl alcohol liquid-liquid procedure was adopted to extract the drug from the milk of sheep. The same method was used for goat milk after exposing the matrices to enzymatic digestion. The extracted samples were analyzed by HPLC. The i.m. disposition kinetics of imidocarb in the 2 species showed significant differences in the rate of elimination (0.0075 +/- 0.002 and 0.025 +/- 0.004 L/h in sheep and goats, respectively), being faster in ewes than in does. Nevertheless, a smaller area under the concentration-time curve (12.21 +/- 0.76 and 9.49 +/- 0.54 microg/mL per h in sheep and goats, respectively), a larger volume of distribution (4.18 +/- 0.44 and 7.68 +/- 0.57 L/kg in sheep and goats, respectively), and a longer mean residence time (9.07 +/- 0.77 and 14.75 +/- 2.20 h in sheep and goats, respectively) were found in goats, suggesting a more rapid and effective drug storage in tissues during the first 48 h after the injection. The concentrations of imidocarb in milk of both species were higher than in plasma. However, a fast passage through the blood-milk barrier and a high storage of imidocarb were observed in the milk of ewes, whereas the drug concentrations were not as high nor was the extent of drug penetration from blood to milk as great in the milk of goats (AUC(milk 0-48)/AUC(plasma 0-48) = 2.5 +/- 0.45 and 1.26 +/- 0.27 in sheep and goat, respectively). Despite the differences in pharmacokinetic behavior, and considering the sensitivity of pathogens to imidocarb, the same dosage regimen can be used for clinical efficacy against Babesia spp. infection in both species. In contrast, the differences in depletion of imidocarb residue in milk and the large variability in mammary drug elimination found in goats suggests that great care should be taken in defining the withdrawal time in small ruminant dairy species.