Determination Of Vancomycin Residues In Fish And Pharmacokinetics In Carp

The advent of antibiotics bring human epoch-making significance,with the continuous development and use of antibiotics are widely used in clinical,agriculture and animal husbandry,it is used to treat many infectious diseases and resistance to pests and diseases.But the overuse of antibiotics has given mankind a devastating disaster,leading to increased bacterial resistance,decreased clinical efficacy of treatment,environmental pollution and produce a range of diseases.Therefore,countries have established a national standard for the detection of antibiotic residues and the relevant regulation of antibiotic abuse.Vancomycin and Norvancomycin are belong to glycopeptide antibiotics,whose are widely used to treat bacterial infection especially super bacteria.These chemical structure and pharmacological properties are similar to antibacterial effect.Because of its efficacy,Vancomycin has become the first choice for the treatment of drug resistant Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.Excessive Vancomycin and Norvancomycin can cause severe ear poisoning and kidney toxicity.And if the consumption of foods of animal origin contain vancomycin class of drugs can lead to vancomycin accumulate in the body,resulting in resistant bacteria harmful to human health.A new method for the determination of glycopeptide antibiotics residues including vancomycin and norvancomycin in fish by high performance liquid chromatography-mass spectrometry?LC-MS/MS?coupled with dual solid-phase extraction was established.Samples were extracted with 0.1%formic acid-acetonitrile solution?7:3,V/V?,defatted by n-hexane saturated with acetonitrile,purified by SPE C18 and PCX column,analyzed under the multiple reaction monitoring?MRM?mode,quantified by Dedichloro vancomycin as internal standard.The results showed good linearity in the range of 2²50 ng/mL,and the correlation coefficient?r²?was greater than 0.99.At the spiked levels of 5,25 and 100 ?g/kg,the average recoveries were in the range of 92.8%⁹6.5% with the relative standard deviations from 4.48% to 6.93%?n=5?.The detection limit?LOD?of this method was 2.0 ?g/kg,and limit of quantitation?LOQ?was 5.0 ?g/kg.The results indicated that this method can be used for the simultaneous determination of Vancomycin and Norvancomycin residues in fish.Then,the method was used to investigate the dissolution efficiency of Vancomycin,Norvancomycin and Dedichloro vancomycin standard dissolved in 0.1% formic acid aqueous solution and methanol solution.At the same time,the stability of the four kinds of storage conditions was preserved under the condition of freezing and avoiding light preservation,preservation of cold storage,preservation of room temperature and preservation of room temperature at room temperature.It was found that Vancomycin,Norvancomycin and Dedichloro vancomycin were better dissolved in 0.1% formic acid aqueous solution,and the preservation effect was better under the condition of cold storage.Vancomycin,Norvancomycin and Dedichloro vancomycin in 0.1% formic acid aqueous solution after freezing and cold storage conditions are not very different,The sensitivity of the dark under the conditions of preservation is higher than not light to save,The stability of Dedichloro vancomycin was the worst compared with that of vancomycin and norvancomycin,which was the most influential with the change of storage days and storage environment.Finally,a pharmacokinetics and residues study of Vancomycin was investigate after following single oral gavage administration in grass carp at?18±1?? water temperature.The concentrations of Vancomycin in carp muscle,plasma,kidney and liver were determined by using the High Performance Liquid chromatography-mass spectrometry.Pharmacokinetic parameters were analyzed with the pharmacokinetic computer program DAS 3.0.5.The results indicated that when carp were taken single-dose Vancomycin 1 mg/kg by oral administration.The plasma concentration time data of Vancomycin could be described by a two-compartment open model.The main pharmacokinetic parameters were as follows: The absorption rate constant?Ka?of Vancomycin was to be 3.745.Whereas the elimination half-life(t_1/2?)of the drug was 39.337 h.The area under the serum concentration-time curve?AUC?was 15.121mg·h/L,the time-point of maximum plasma concentration of the drug(T_max)and the maximum plasma concentration(C_max)were calculated as 3h and 216.58?g/L.The study found that the concentration of vancomycin in the liver and kidney was significantly higher than that of muscle and plasma,with the highest concentration of 632.5?g / kg in the liver,followed by kidney,muscle and blood.Vancomycin in the carp muscle,plasma and liver easier to absorb,and the time-point of maximum plasma concentration of the drug Tmax 3h,kidney of 72 h.It indicated that the elimination of Vancomycin in the liver and kidneys of carp is very slow,elimination half-life is far greater than muscle and plasma.The elimination half-life t_1/2? of muscle,plasma,liver and kidney was 39.337 h,189.521 h,636.834 h,627.195 h respectively,and the overall clearance rates in the liver and kidneys were 0.003L/h/kg and 0.006L/h/kg.In this study,vancomycin in carp in the main organization of the drug metabolism process and the elimination of the law,and to provide a method and scientific basis for relevant departments to carry out supervision and detection of Vancomycin.