Abstract: Pharmacokinetics of quinocetone and its three main metabolites in swine were investigated in this study. Quinocetone was administered to 7 healthy cross-bread swine orally at a dosage of 40 mg/kg,The concentration of quinocetone and its major metabolites in plasma were detected using the high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) method,the concentration-time data were analyzed with WinNonlin5.2 program. After oral administration, quinocetone and its three major metabolites were detected. Plasma drug concentration-time data of quinocetone after oral administration was found to be fitted to one compartment open model with first order absorption and its pharmacokinetic parameters were as follows: T_1/2Ka＝(0.97±0.08)h,T_1/2λz＝(2.79±0.16)h,CL＝(26.03±0.65)L/h·kg,Cmax＝(0.26±0.01)μg/mL,Tmax＝(2.23±0.06)h,AUC＝(1.54±0.04)h·μg/mL. Plasma drug concentration-time data of demonoxyquinocetone and desoxyquinocetone were analyzed by non-compartmental model and its pharmacokinetic parameters were respectively as follows:demonoxyquinocetone, Tmax＝(6.33±1.37)h,Cmax＝(8.81±2.08) ng/mL,T_1/2λz＝(3.03±1.27)h,AUC＝(0.07±0.01)h·ng/mL,MRT＝(6.58±0.40)h;desoxyquinocetone,Tmax＝(10.29±0.29)h,Cmax＝(6.20±1.11)ng/mL,T_1/2λz＝(5.84±2.78)h,AUC＝(0.15±0.01)h·ng/mL,MRT＝(3.64±0.72)h.MQCA were detected in several samples. Quinocetone was rapidly absorbed and metabolized in swine after oral administration;three metabolites were detected,but their concentration were low.

Key words: quinocetone; swine; pharmacokinetics; HPLC-MS/MS