Distribution and elimination of [ 14C] sarafloxacin hydrochloride from tissues of juvenile channel catfish (Ictalurus punctatus)

• Published in: Aquaculture 1995-03, Vol.131 (1), p.23-36
• Main Authors: Gingerich, W.H., Meinertz, J.R., Dawson, V.K., Gofus, J.E., Delaney, L.J., Bunnell, P.R.
• Format: Article
• Language: English
• Subjects: Animal aquaculture; Animal productions; Aquaculture; Biological and medical sciences; Disease; Diseases and their control—fish; Distribution; DRUG THERAPY; DRUGS; Elimination; Fish; FORMAS JUVENILES; Freshwater; Fundamental and applied biological sciences. Psychology; ICTALURUS; Ictalurus punctatus; JUVENILE; JUVENILES; MEDICAMENT; MEDICAMENTOS; Pisciculture; Sarafloxacin; TERAPEUTICA MEDICAMENTOSA; THERAPEUTIQUE MEDICAMENTEUSE; Vertebrate aquaculture
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/0044-8486(94)00362-R

The distribution and loss of radioactivity from tissues were determined in 60 juvenile channel catfish ( Ictalurus punctatus) following oral dosing with the candidate fish therapeutant Sarafin ® ([ 14C] sarafloxacin hydrochloride) at 10 mg/kg for 5 consecutive days. Twelve groups of 5 fish each were sampled at selected times ranging from 3 to 240 h after the last dose was administered. The concentration and content of sarafloxacin-equivalent activity was determined in liver, gallbladder, kidney, skin, and skinless fillet by sample oxidation and liquid scintillation counting; content of sarafloxacin-equivalent activity was determined in stomach and anterior and posterior intestines. Skinless fillet tissues were also analyzed for sarafloxacin and for potential metabolites by gradientelution high-performance liquid chromatography (HPLC) with in-line radiometric and fluorescence detection. Loss of radioactivity from the whole body conformed to a bimodal elimination pattern with a rapid initial phase ( t 1 2 = 11 h ) and a slower secondary phase ( t 1 2 = 222 h ). Tissue and contents of the gastrointestinal tract (i.e. stomach and anterior and posterior intestines) were a principal depot of activity during the first four sample times (3, 6, 12, and 24 h); the combined head, skeleton, and fins (i.e. residual carcass) were the principal depot of activity in samples taken after 24 h. Of those tissues sampled 3 h after the last dose, relative sarafloxacin concentration was greatest in the liver (4.06 μg equivalents/g) and least in the residual carcass (1.13 μg equivalents/g). Intermediate concentrations were found in the kidney (2.04 μg equivalents/g), skinless fillet (1.71 μg equivalents/ g), and the skin (1.51 μg equivalents/g). Concentrations of sarafloxacin-equivalent residues in edible skinless fillet were consistently among the lowest of all tissues examined. The highest mean concentration of parent-equivalent material in the fillet tissue was found 12 h after administration of the last dose (2.27 μg equivalents/g) and declined thereafter. Sarafloxacin constituted between 80 and 90% of the extractable radioactive residues from the fillet homogenates. No other peaks were resolved in any of the fillet tissue samples analyzed by HPLC with in-line radiometric detection.