We found that the peak plasma concentrations ( C ( max ) ) increased dose dependently ( 0.41 0.14 , 0.89 0.55 , and 1.56 0.50 g/ml ) , but the times to C ( max ) ( 23.0 15.8 , 23.1 14.5 , and 20.8 11.5 min ) were not different between 0.25 , 0.5 , and 0.75 % ropivacaine doses , respectively .