RESULTS	After intravenous injection , parent drug rapidly declined and was converted to dihydroartemisinin ( DHA ) with overall mean elimination half-lives ranging 0.15-0 .23 hr for AS and 1.23-1 .63 hr for DHA , but the peak concentration ( C ( max ) ) of AS was much higher than that of DHA with a range of 3.08-3 .78 - folds .\