[Objective] A study on the diminazene-protein binding rate in swine was carried out in this ex-periment for further clinical application efficiency and safety .[Method] The plasma samples were pretrea-ted to separate free drug by ultrafiltration .A high performance liquid chromatographic-UV ( HPLC-UV) method was used to measure the amount of free diminazene in plasma .Then the drug-protein binding rate was accounted .Six swine were administrated intramuscularly at a dosages of 7 and 14 mg/kg.The plas-ma samples were collected and the protein binding rates in vivo were determination at 3, 5, 15, 60 min.[Result and conclusion] Diminazene-protein binding rate tested in vitro was within the range of 74.68%-95.90%.Although the drug-protein binding rate in vivo was within the range of 84.11% -89.69%(7 mg/kg, i.m.), and 82.96%-88.65%(14 mg/kg, i.m.) after administration, and saturation phe-nomenon emerged as dosage increased .These factors should be considered in clinical regimens designing .

用乙二胺四乙酸二钠溶液稀释猪血浆样品,用SEP-PAK-C18固相萃取小柱富集药物,再以含有离子对试剂的乙腈洗脱.以氮气吹干洗脱液,流动相复溶后测定药物的质量浓度.HPLC分析柱为BDS C18,流动相组成为V(乙腈)∶V(pH 3.2的0.005 mol/L辛烷磺酸钠溶液)=30∶70,紫外检测波长372 nm.猪血浆中三氮脒的质量浓度在0.01～40.0 μg/mL范围内可准确定量;血浆中三氮脒的质量浓度为0.05、0.5、10 μg/mL时,相对回收率≥89.09％,批间变异系数在0.81％～4.41％之间.猪血浆中三氮脒的定量限为5ng/mL,检测限为2 ng/mL.结果表明,本研究建立的HPLC方法操作简单、重复性和灵敏度好,定量范围宽,适用于检测猪血浆样品中三氮脒的质量浓度.