| Mandarin fish(Siniperca chuatsi),commonly known as osmanthus fish,is a valuable specie in China aquaculture,and usually known as "freshwater grouper".However,the farmed mandarin fish are seriously threatened by variety of bacterial diseases,caused huge lossed to aquaculture.Florfenicol and oxolinic acid are widely used as important drugs for fish,but there are no report about research on the pharmacokinetics and residual law of florfenicol and oxolinic acid in mandarin fish at present.In this study,the absorption,distribution and elimination of florfenicol and oxolinic acid in Siniperca chuatsi were studied by HPLC,and the findings of this study will contribute to the reduction of residual risk,and lay the scientific basis for the rational use of drugs in the prevention and control of Siniperca chuatsi disease.The specific experimental results are as follows:At the temperature of 28 ± 2 ℃,florfenicol was given at a dose of 12 mg/kg for oral administration twice a day for three days.Plasma,muscle,liver and kidney were extracted and analyzed by HPLC method and the results were analyzed using non-compartmental model in software DAS3.2 and withdrawal time software WT1.4.The results showed that the absorption and distribution of florfenicol were fine after the oral administration,and the curve was "double peak",and Tmax was 4 h.The peak concentration C max in plasma,muscle,liver and kidney was 10.42、7.62、5.55 and 3.18 mg/L(kg)respectively;and the area under the curve AUC0-t were 166.57,121.56,107.38 and 84.30 mg/L(kg).After repeatedly oral administration of florfenicol in Siniperca chueno,the drug eliminated fastest in the blood and slowest in liver,the elimination half-life t1/2z in plasma,muscle,liver and kidney were 10.55,22.95,25.09 and 11.36 h respectively,with a ranking of liver > muscle > kidney > plasma In this study,the florfenicol on the mandarin fish can be 12 mg/kg dose for administration,once every 12 h,for 3-5 days.At the temperature of 28 ± 2 ℃,the oxalic acid was ad ministered at a dose of 20 mg/kg for single time or continuous administration once a day for 3 d.After administration,the plasma,muscle,liver and kidney of the Siniperca chuatsi were extrated and analyzed by HPLC method,and the results were analyzed using non-compartmental model in software DAS3.2 and withdrawal time software WT1.4.The results showed that the single oral administration of oxalic acid in mandarin fish was well distributed in all the tissues,and kept a higher levels in the blood.The curves were with high similarities in all the tissues,and Tmax was 12 h,C max was 9.29,1.15,3.54 and 7.82 mg/L,AUC0-t were 316.77,18.00,89.83 and 224.42 mg·h/L,respectively.After repeatedly oral administration of oxalic acid in Siniperca chueno,the elimination half-life t1/2z in plasma,muscle,liver and kidney were 6.53,13.97,9.68 and 17.47 mg/L(kg)respectively,with a ranking of kidney> muscle> liver > pla sma.The resuls suggested that the o xalic acid can be used of 20 mg/kg dose on the mandarin fish,and administration once every 2 d after the first administration,for 6 days or more.In conclusion,the results show that under the conditions of this study,with the advantage of evenly distributed after absorption,fast metabolic elimination,low drug dosage and short withdrawal time,florfenicol is very suitable for the control of bacteria disease of mandarin fish;oxalic acid is also have the advantage of well distributed,strong metabolic elimination,and low residual risk,and is considered to be suitable for the treatment of bacterial disease of mandarin fish. |
