Blood samples were drawn immediately before taking the drug , then at @ and @ minutes , and @ , @ , @ , @ , @ , @ , @ , @ , @ , @ , @ , @ , and @ hours after dosing , to evaluate pharmacokinetic parameters of the single dose administration , ie , the area under the plasma concentration-time curve ( AUC ) from time zero to @ hours ( AUCt ) , AUC from time zero to infinity ( AUC ( inf ) ) , the peak plasma concentration of the drug ( Cmax ) , time needed to achieve Cmax ( tmax ) , and the elimination half-life ( t@/@ ) .