Pharmacokinetics and residues of oxytetracycline and oxolinic acid in black tiger shrimp (Penaeus monodon) and the effect of cooking on the residues

pharmacokinetics and residues of oxytetracycline (OTC) and oxolinic acid (OA) examined in oxytetracyclineblack tiger shrimp （Penaeus monodon）18- 25g shrimp) after intra-sinus (10mg /kg) and oral (50mg /kg) administration. The shrimp werekept in tanks with seawater at a salinity of 5- 10ppt . The water temperature was adjusted to 28-29℃。The hemolymph concentrations of both drugs after intra-sinus dosing were最佳描述two-compartment open model. The following equations were obtained to描述The time course ofhemolymph levels for two drugs:Oxytetracycline：Ct=35.4·exp(-3.5303·t)+10.6·exp(-0.0429·t)Oxolinic acid：Ct=9.96 . exp(-0.8252 . t)+3.88 . exp(-0.0391 . t)The distribution and elimination half-lives were found tobe 0.2 and 16.2 h for OTC and 0.84 and 17.7 h for OA. The apparent volume of distribution at asteady state and total body clearance were estimated to be 869 ml/kg and 38.7 ml/kg/h for OTC and2,061 ml/kg and 90.1 ml/kg/h for OA，respectively.The peak hemolymph concentration and the time to peak hemolymph concentration followingoral dose were 21.1 μg/ml at 4h for OTC and 4.20 μg/ml at 4h for OA. The bioavailability afteroral administration was 35.6% for OTC and 7.9% for OA. The elimination half-life of muscle was 22.0h for OTC and 20.2 h for OA. The elimination half-life of shell was 21.9 h for OA, however，for OTC the elimination half-life of shell无法调用because the drug residues persistedin shell tissues.Residual OTC in muscle was reduced to the boiling for 4min and frying at shell tissues.Residual OTC in muscle was reduced to 50% - 60%180℃for 1 min, and 30 ~ 40% baking at 200℃for 4 min. However，the reduction levels in shell were only 20%. Residual OA was 20 - 30% in muscle and shell by thecooking。

The pharmacokinetics and residues of oxytetracycline (OTC) and oxolinic acid (OA) were examined in black tiger shrimp (Penaeus monodon, 18-25 g shrimp) after intra-sinus (10 mg/kg) and oral (50 mg/kg) administration. The shrimp were kept in tanks with seawater at a salinity of 5-10 ppt. The water temperature was adjusted to 28-29℃. The hemolymph concentrations of both drugs after intra-sinus dosing were best described by a two-compartment open model. The following equations were obtained to describe the time course of hemolymph levels for two drugs :Oxytetracycline : Ct=35.4・exp(-3.5303・t)+10.6・exp(-0.0429・t)Oxolinic acid : Ct=9.96・exp(-0.8252・t)+3.88・exp(-0.0391・t)The distribution and elimination half-lives were found to be 0.2 and 16.2 h for OTC and 0.84 and 17.7 h for OA. The apparent volume of distribution at a steady state and total body clearance were estimated to be 869 ml/kg and 38.7 ml/kg/h for OTC and 2,061 ml/kg and 90.1 ml/kg/h for OA, respectively.The peak hemolymph concentration and the time to peak hemolymph concentration following oral dose were 21.1 μg/ml at 4 h for OTC and 4.20 μg/ml at 4 h for OA. The bioavailability after oral administration was 35.6% for OTC and 7.9% for OA. The elimination half-life of muscle was 22.0 h for OTC and 20.2 h for OA. The elimination half-life of shell was 21.9 h for OA, however, for OTC the elimination half-life of shell could not calculated because the drug residues persisted in shell tissues.Residual OTC in muscle was reduced to 50〜60% by the boiling for 4 min and frying at 180℃ for 1 min, and 30〜40% baking at 200℃ for 4 min. However, the reduction levels in shell were only 20%. Residual OA was 20〜30% in muscle and shell by the cooking.