Median time to clinically relevant response as estimated by 50 % reduction in clinical signs and symptoms ( CSS ) total score over the entire trial was similar for subjects treated with HC-ac 2.5 % ( 73.5 h ) and for subjects treated with HC-ac 1.0 % ( 67.7 h ) and was considerably and significantly longer for subjects treated with HC-ac 0.5 % ( 111.8 h ) [ p < 0.001 for both dosages ] .