Depletion study and estimation of the withdrawal period for oxytetracycline in tilapia cultured in Brazil

Autor(es)

Paschoal, J. A. R. ^[1] ; Bicudo, A. J. A. ^[2] ; Cyrino, J. E. P. ^[2] ; Reyes, F. G. R. ^[3] ; Rath, S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Dept Analyt Chem, Inst Chem, BR-13084971 Campinas, SP - Brazil

^[2] Univ Sao Paulo, Escola Super Agr Luiz Queiroz, Dept Zootecnia, Piracicaba, SP - Brazil

^[3] Univ Estadual Campinas, Sch Food Engn, Dept Food Sci, BR-13084971 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS; v. 35, n. 1, p. 90-96, FEB 2012.
• Citações Web of Science: 9

Resumo

Defining pharmacokinetic parameters and depletion intervals for antimicrobials used in fish represents important guidelines for future regulation by Brazilian agencies of the use of these substances in fish farming. This article presents a depletion study for oxytetracycline (OTC) in tilapias (Orechromis niloticus) farmed under tropical conditions during the winter season. High performance liquid chromatography, with fluorescence detection for the quantitation of OTC in tilapia fillets and medicated feed, was developed and validated. The depletion study with fish was carried out under monitored environmental conditions. OTC was administered in the feed for five consecutive days at daily dosages of 80 mg/kg body weight. Groups of ten fish were slaughtered at 1, 2, 3, 4, 5, 8, 10, 15, 20, and 25 days after medication. After the 8th day posttreatment, OTC concentrations in the tilapia fillets were below the limit of quantitation (13 ng/g) of the method. Linear regression of the mathematical model of data analysis presented a coefficient of 0.9962. The elimination half- life for OTC in tilapia fillet and the withdrawal period were 1.65 and 6 days, respectively, considering a percentile of 99% with 95% of confidence and a maximum residue limit of 100 ng/g. Even though the study was carried out in the winter under practical conditions where water temperature varied, the results obtained are similar to others from studies conducted under controlled temperature. (AU)

• Processo FAPESP: 04/07312-9 - Residuos de antimicrobianos em alimentos:oxitetraciclina e acido oxolinico em peixes.
• Beneficiário: Susanne Rath
• Modalidade de apoio: Auxílio à Pesquisa - Regular