complete analysis of oxytetracycline pharmacokinetics in farmed Pacific white shrimp (Litopenaeus vannamei)

• Published in: Journal of veterinary pharmacology and therapeutics Vol. 29; no. 5; pp. 409 - 414
• Main Authors: CHIAYVAREESAJJA, S, CHANDUMPAI, A, THEAPPARAT, Y, FAROONGSARNG, D
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.10.2006; Blackwell Publishing Ltd
• Subjects: animal tissues; Animals; Anti-Bacterial Agents - pharmacokinetics; application methods; Area Under Curve; Chromatography, High Pressure Liquid; digestive gland; dosage; drug excretion; Half-Life; hemolymph; intrasinusal administration; Litopenaeus vannamei; Male; muscles; oxytetracycline; Oxytetracycline - pharmacokinetics; Penaeidae; pharmacokinetics; shrimp; shrimp culture; temporal variation; Tissue Distribution
• ISSN: 0140-7783; 1365-2885
• DOI: 10.1111/j.1365-2885.2006.00785.x

Lack of dosing information of the major antibiotics known as oxytetracycline (OTC) for the Pacific white shrimp (Litopenaeus vannamei) could have harmful impact on aquaculture in Thailand. The aim of this study was to detail complete pharmacokinetic information of OTC in the Pacific white shrimp. Sixty-four male L. vannamei weighing 14-22 g with carapace length of 2.30-3.00 cm in the standardized moulting stage of C-D₀ were used for the investigations. Single dose, 10 μg/g body weight OTC solution was administered intra-sinusally (i.s.), and the shrimps were then sampled in three replicates at time intervals of 0.25, 0.5, 2, 4, 6, 9, 12, 24, 48, 72, 170, 336 and 504 h postdose. OTC levels with time intervals in biological matrices including the hemolymph, abdominal muscle, and digestive gland of each sample were determined by validated high-performance liquid chromatography, and were analyzed with noncompartment and compartment models. A simplified two-compartment model was employed rather than a more complicated model, with additional digestive compartment if necessary. A significant portion of the OTC was found in the digestive glands, even though the OTC was administered i.s. The model indicated that the OTC was thus not only distributed into the tissue compartment, but also to the digestive gland, from where it was eliminated from the shrimp's body. The dispositional half-lives of all compartments was found to be 14-21 h. Approximately 60% of the drug elimination took place in digestive gland, which is proposed to be the major route of elimination.