Study On The Elimination Of Praziquantel And Its 4-Hydroxy-Praziquantel In Tilapia

As a highly effective,low-toxic,broad-spectrum antiparasitic agent,praziquantel is widely used in the treatment of parasitic diseases in humans and livestock.Praziquantel also has good effects on parasitic diseases of freshwater fish such as aphids,spines and nematodes.In this study,the residue elimination of praziquantel and its 4-hydroxyl metabolites in tilapia were investigated by high performance liquid chromatographic method established.Tilapia?body weight 495.4⁵22.2 g?was regularly sampled after intragastric administration at a single dose of 10 mg praziquantel kg^-1 b.w.,and then fish muscle samples were extracted with ethyl acetate and purified by freeze-thaw approach.Subsequently,the target analytes were separated by Agilent EC-C₈ column?250 mm×4.6mm,5?m?using acetonitrile and ultrapure water as mobile phases with isometric elution program.Praziquantel and 4-hydroxyl metabolites were detected at UV 210 nm and quantified by external standard method.Results showed that praziquantel and its4-hydroxyl metabolites?trans-4-hydroxy-praziquantel and cis-4-hydroxy-praziquantel?were in good linear in the experimental concentration range,and the correlation coefficients?r²?were more than 0.99.The limits of detection in tilapia muscle were 0.01?g/g,and the limits of quantitation were 0.02?g/g.In three spiked levels of 0.05?g/g,0.2?g/g and 0.5?g/g,The average recoveries of praziquantel and 4-hydroxyl praziquantel ranged from 71.4%to96.9%,the intra-assay coefficient of variation was less than 9.7%,and the inter-assay coefficient of variation was less than 6.9%.The residue amounts of praziquantel,trans-4-hydroxy-praziquantel and cis-4-hydroxy-praziquantel in muscle tissue of tilapia were below the detection limits at 36 h,48 h and 24 h,respectively.Trans-4-hydroxy-praziquantel metabolites were eliminated slowly,and later residue amount were higher than praziquantel.