Study On The Pharmacokinetics And Residue Elimination Of Decoquinate Suspension In Brolier

Chicken coccidiosis is one of the most common intestinal parasitic diseases in poultry industry.In production practice,coccidiosis is the most harmful to chicks and young rabbits.The use of chemotherapy drugs to prevent coccidiosis is still an important means.Decoquinate is a new quinoline broad-spectrum anti-coccidiosis drug which is widely used to prevent chicken coccidiosis in clinical veterinary.The highly effective anticoccidial activity of decoquinate has inspired people to try to develop new preparations to facilitate clinical use.Decoquinate suspension is recently developed a new formulation for decoquinate.The study on the pharmacokinetics and residue elimination of decoquinate dry suspension in chickens not only provides the basis for the development of new preparations and establishment of withdrawal period,but also has important practical significance for guiding clinical rational drug use and ensuring the safety of animal-derived food.1.Pharmacokinetic study of decoquinate dry suspensionFifty-day-old healthy white feather broilers(male and female in half)were randomly assigned to two groups,one group of 10 animals were intravenously injected with decoquinate solution at a single dose(2 mg/kg bw),and the other group of 12 were orally infused with decoquinate dry suspension at a single dose(10 mg/kg bw).Blood samples were collected at a given time after administration,and the concentration of decoquinate in plasma was measured using the validated HPLC assay.The pharmacokinetic parameters will be estimated using non-compartment pharmacokinetic techniques by the Kinetica pharmacokinetic analysis software.The parameters of main pharmacokinetic are following after single dose intravenous administration:the mean elimination half-life(t1/2β)was 29.22±18.28 h,the mean apparent volume of distribution(Vz)was 7.84±3.03 L/kg,the mean body clearance(CLb)was 3.55±1.24ml/min/kg,the mean area under the drug-time curve(AUC)was 4945.91±1409.76(mg/L)·h.The results showed that decoquinate was widely distributed in the chicken body,and the elimination was slow.Only a trace amount of the drug was detected in the blood of chickens after oral administration of decoquinate dry suspension,which indicated that there was little absorption after gastrointestinal administration of decoquinate,suggesting that there was little residual in the edible tissues of chickens after oral administration of decoquinate.2.Study on the residue elimination of decoquinate dry suspensionIn this study,Fifty-day-old healthy white feather broilers were used as experimental subjects to study the residue elimination of decoquinate dry suspension in commercial broilers,so as to provide the basis for the establish of withdrawal period.The test drug was continuously given by drinking water with 30 mg/L(by decoquinate)for 8 days.Five chickens were randomly selected and slaughtered at 4 h,1 d,3 d,5 d and 7 d after withdrawal of drug,respectively.The edible tissue of chicken was collected,and the residue of decoquinate in the edible tissue of chicken were determined using the validated HPLC assay.The results showed that the residue of decoquinate in fat/skin was the highest and the elimination was the slowest,the residue followed in liver,and the residue in muscle was the lowest and the elimination was fast.Results of residual elimination suggest that fat/skin or liver could be identified as the residual target tissues of decoquinate in chicken.Decoquinate dry suspension was given by drinking water at dosage regimen,the withdrawal period could be set as 0 day.