Pharmacokinetics of doxycycline in tilapia (Oreochromis aureus × Oreochromis niloticus) after intravenous and oral administration.
The pharmacokinetics of doxycycline was studied in plasma after a single dose (20 mg/kg) of intravenous or oral administration to tilapia (Oreochromis aureus × Oreochromis niloticus) reared in fresh water at 24 °C. Plasma samples were collected from six fish per sampling point. Doxycycline concentrations were determined by high-performance liquid chromatography with a 0.005 μg/mL limit of detection, then were subjected to noncompartmental analysis. Following oral administration, the double-peak phenomenon was observed, and the first (Cmax1 ) and second (Cmax2) peaks were 1.99 ± 0.43 μg/mL at 2.0 h and 2.27 ± 0.38 μg/mL at 24.0 h, respectively. After the intravenous injection, a Cmax2 (12.12 ± 1.97 μg/mL) was also observed, and initial concentration of 45.76 μg/mL, apparent elimination rate constant (λz) of 0.018 per h, apparent elimination half-life (t1/2λz) of 39.0 h, systemic total body clearance (Cl) of 41.28 mL/h/kg, volume of distribution (Vz) of 2323.21 mL/kg, and volume of distribution at steady-state (Vss) of 1356.69 mL/kg were determined, respectively. While after oral administration, the λz, t1/2λz, and bioavailability of doxycycline were 0.009 per h, 77.2 h, and 23.41%, respectively. It was shown that doxycycline was relatively slowly and incompletely absorbed, extensively distributed, and slowly eliminated in tilapia, in addition, doxycycline might undergo enterohepatic recycling in tilapia.
College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China; College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
F
F
Yang
Z L
ZL
Li
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Q
Shan
Z L
ZL
Zeng
D000284:Administration, Oral; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D004318:Doxycycline / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D017619:Hemibody Irradiation; D007275:Injections, Intravenous; D017210:Tilapia / Q000097:blood / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D004318:Doxycycline