Pharmacokinetics Of Enrofloxacin In Manila Clam Ruditapes Philippinarum Following Bath Treatment

A pharmacokinetic study of enrofloxacin (EF) following a bath administration was carried out in Manila clam Ruditapes philippinarum. Hemolymph and tissue concentrations of EF were determined by HPLC.The result showed that EF was distributed efficiently to hemolymph and tissues, with constantly the highest concentration in hemolymph. The concentrations of EF in hemolymph and tissue were significantly correlated with water drug concentration or time of exposure to medicated water. The concentrations of EF in Manila clam occurred in order: hemolymph>gill>visceral mass>foot>adductor muscle. This phenomenon is in accord with their physiological characteristics. The equations of elimination curve of enrofloxacin in hemolymph, gill, visceral mass, foot and adductor muscle were C=6.995e-0.0853t, C=2.7957e -0.1177t, C=1.539e-0.1013t, C=1.7015e-0.1535t, C=2.010e-0.1414t, respectively. The elimination ofhalf-lives (T1/2β) was 6.284, 5.889, 6.483, 4.516, 3.679h, respectively.The study on the influence of temperature and salinity on the tissue distribution and depuration of enrofloxacin in Manila clam Ruditapes philippinarum following bath treatment indicated that the elimination of EF in clam held at higher temperature was more rapid than clam held at lower temperature and that the elimination half-life in clam fed at higher salinity was shorter than clam fed at lower salinity. The elimination half-lives in hemolymph were 17.548h at 16℃/30‰, 6.284h at 22℃/30‰, 16.309h at 22℃/20‰ and in gill were 20.208h at 16℃/30‰, 5.889h at 22℃/30 ‰,17.865h at 22℃/20‰, respectively.This study provided information for further laboratory and field studies of this compound in the shellfish.