Pharmacokinetics and Residues of Norfloxacin in Hybrid Tilapia

In order to study the metabolism and elimination of norfloxacin (NFX) in hybrid tilapias (Oreochromis aureusO.niloticus), single oral administration at dose of 20 mgkg-1 had been investigated in healthy tilapia at (252)℃.The result demonstrated: Plasma concentration-time datas of NFX were best fitted using a two-compartmental open model.Absorption, distribution and elimination half-life were 1.30,1.97 and 26.36 hours, respectively.The maximal plasma concentration was 0.546 gmL-1, peaking at 2.715 hour.Area under the plasma drug concentration-time curve was 14.491 ghmL-1.As an edible tissue, muscle was selected as target tissue in this experiment.The maximum residue limit (MRL) is 10 gkg-1 in muscle, the withdrawal time should not be less than 55 days under this experiment condition.