For the 0.1 - , 0.3 - , 1.0 - , and 3.0-mg / kg dose groups , respectively , mean maximum plasma concentrations were 0.6 , 1.4 , 5.6 , and 14.5 g/mL and mean elimination half-lives were 20.6 , 16.8 , 17.6 , and 21.2 days .