Pharmacokinetics And Residue Elimination Of Six Antibacterials In Lateolabrax Japomicus

This paper studies the six kinds antibacterial drug in Lateolabrax japomicus in vivo pharmacokinetics dynamics,tissue distribution and residue depletion law provides a theoretical basis for the development of rational drug program and the withdrawal period.the six kinds antibacterial drug were Oxilinic acid,Norfloxacin,Sarafloxacin hydrochloride,Doxycycline hydrochloride,Neomycin sulfate and Florfenicol,respectively.The water temperature and middle weight of Lateolabrax japomicus were?22±1?? and?505.3±70.5?g.For pharmacokinetics and residue depletion law analysis,the dose were 20 and 60 mg/kg body weight.Pharmacokinetic analysis showed that after oral administration of mixed feed at the dose 20 mg/kg,the peak concentration(C_max)of Oxilinic acid,Norfloxacin,Sarafloxacin hydrochloride,Doxycycline hydrochloride were 2.761,2.224,1.824,4.560,8.925 and 18.356 ?g/m L in Lateolabrax japomicus,respectively.The peak time(T_max)were 3,4,3,3,3 and 3 h.C_max was all reached in 3 or 4 h,but was significant difference.The absorption rate?T1/2Ka?were 0.944,1.134,0.371,1.643,1.059 and 0.161 h,the elimination half-life(T_1/2z)were 6.389,22.166,10.760,9.116,14.196 and 12.508 h.The elimination half-life were 1.997,1.809,1.354,0.979,1.597 and 1.188 d after oral administration of mixed feed at the dose 60 mg/kg in mucle of Lateolabrax japomicus.The maximum residue limits?MRL?of Oxilinic acid,Sarafloxacin hydrochloride,Doxycycline hydrochloride,Neomycin sulfate and Florfenicol were 300,30,100,500 and 1000 ?g/kg in fish according to the 235 announcement of the Ministry of Agriculture.If 50 ?g/kg is the highest residue limits,the withdrawal period of Oxilinic acid were 11.81 d in muscle,14.01 d in liver,12.61 d in kidney and 7.01 d in plasma.The withdrawal period of Norfloxacin were 17.89 d in muscle,25.23 d in liver,20.99 d in kidney and 11.20 d in plasma.The withdrawal period of Sarafloxacin hydrochloride were 13.22 d in muscle,11.56 d in liver,19.98 d in kidney and 12.31 d in plasma.The withdrawal period of Doxycycline hydrochloride were 8.76 d in muscle,9.93 d in liver,9.74 d in kidney and 6.52 d in plasma.The withdrawal period of Neomycin sulfate were 9.58 d in muscle,9.04 d in liver,15.89 d in kidney and 6.15 d in plasma.The withdrawal period of Florfenicol were 6.54 d in muscle,8.69 d in liver,8.30 d in kidney and 5.89 d in plasma.The results provided theortical basis for practical applications of six antibacterials in aquatic animals.