Cheng Pei-pei;Hu Xing-xing;Wang Chun-mei;Liu Ying-chun;Fei Chen-zhong;Zhang Li-fang;Wang Xiao-yang;Zheng Wen-li;Xue Fei-qun

Chinese Acad Agr Sci, Shanghai Vet Res Inst, Minist Agr & Rural Affairs, Key Lab Vet Chem Drugs & Pharmaceut, Shanghai 200241, Peoples R China

ethanamizuril solution;coccidiosis;pharmacokinetics;chickens

Ethanamizuril (EZL) is a novel triazine anticoccidial compound that has high anticoccidial activity in chickens. In order to treat coccidiosis rationally in poultry, a detection method was developed for ethanamizuril in broiler plasma, and then the pharmacokinetics studies were performed in broilers after oral administration of different dose levels. Ethanamizuril was administered as single oral doses at low (0.67 mg kg(-1) BW), medium (1.33 mg kg(-1) BW) and high (6.67 mg kg(-1) BW) levels in which the medium dose was that recommended in clinics. Plasma concentrations of ethanamizuril were determined using ultra-high performance liquid chromatography and the data were analyzed with a non-compartmental model. Peak plasma concentrations of ethanamizuril were (2.16 +/- 0.57), (3.91 +/- 0.71), and (23.71 +/- 5.02) mg L-1 at (5.17 +/- 1.80), (4.60 +/- 2.12), and (4.60 +/- 2.12) h, respectively. The terminal elimination half-lives (t(1/2 Lambda z)) for ethanamizuril were (10.84 +/- 2.59), (10.66 +/- 2.47), and (13.34 +/- 3.10) h after oral administration at low, medium and high doses, respectively. The areas under the concentrationtime curve (AUC(0-t)) were (37.68 +/- 6.87), (73.19 +/- 9.18), and (485.76 +/- 125.10) mg L-1 h with mean residence times (MRT0-t) of (14.79 +/- 3.03), (15.57 +/- 3.69), and (20.22 +/- 4.01) h at the 3 dosages, respectively. Ethanamizuril was absorbed rapidly and eliminated slowly. A comparison across the dose range indicated that the time to reach peak plasma concentration (T-max) values were similar while peak plasma concentration (C-max) and AUC(0-t) were positively correlated with increasing dosages. This study of the pharmacokinetics of an ethanamizuril solution in chickens provides a theoretical basis for the rational use in the clinic.