Establishment Of HPLC Fluorescence Detection Method For Plasma Trace Ivermectin And Its Pharmacokinetics In Bactrian Camel

Ivermectin is a widely used veterinary antiparasitic drug in clinical use.It has many advantages such as wide spectrum,high efficiency,low toxicity and safety,and has a good killing and prevention effect on digestive tract nematodes,lung nematodes and ectoparasite of cattle,sheep,horses,camels and other animals.The purpose of present study was to determine the plasma drug concentration of ivermectin injection in the Phoenix Win Nolin7.0 software to study the pharmacokinetic characteristics and compare the characteristics of the drug in the camel.First,randomly selected 12 healthy Bactrian camel without ivermectin and similar drugs,then divided into high dose group（0.3 mg/kg）and low dose group（0.2 mg/kg）,by neck subcutaneous injection,centrifugation after blood collection,after C18 solid phase extraction column enrichment purification,elute ivermectin with methanol,Blow-dried with 50℃of nitrogen gas,and then after fluorescence derivatization;The derivative reagents are:trifluoroacetic anhydride and N-methimidazole.The HPLC detection conditions are as follows:mobile phase（methanol:acetonitrile=1:1）:water=95.8:4.2,flow rate of 1.00 m L/min,temperature of 35℃,sample intake of 20u L,excitation wavelength of 365 nm,emission wavelength of 475 nm,chromatogram interception time of 10min,and the internal standard is Doramin.The ratio of the peak area of ivermectin is the ordinate,the concentration value of ivermectin is the standard curve of the standard coordinate,the ivermectin plasma drug concentration was calculated according to the standard curve,and the blood concentration data was processed according to the Non-atrial modelusing Phoenix Win Nolin 7.0software,and the relevant pharmacokinetic parameters were analyzed.The results show that ivermectin scales well linearly in the concentration range of0.025 to 5 ng/m L（y=0.6946x+0.0088,R²=0.9988）,The lower limit of quantification was25.00 pg/m L,ivermectin recovery was higher than 70%,RSD was less than 7%,and the retention times for Dometrin and Ivermectin were 6.943 min and 8.545min,respectively.The pharmacokinetics characteristics of ivermectin in the double-peak camel are significantly different from the general livestock such as cattle and sheep,and have secondary absorption.Compared with the two dose groups,the peak time(_Tmax),average residence time（MRT）,apparent distribution volume（Vd）,while the peak concentration(C_max)and the area under the curve（AUC）were about 1.5 times that of the low dose group(C_maxis 1.709±0.27 ng/m L,AUC is 42.443±12.14 d·ng/m L,low dose group:C_maxis1.080±0.32 ng/m L,and AUC is 29.085±7.12 d·ng/m L),which is proportional to the injection dose.In this study,the HPLC fluorescence detection method of ivermectin in plasma was successfully established,and found that the main pharmacokinetics parameters of ivermectin injection in ruminant animals and cattle,sheep,C_maxis low,T_maxis long,and obvious secondary absorption phenomenon,ivermectin absorption in bimodal camel,wide distribution,and the peak concentration and drug curve were positively correlated with the dose.