Day-to-day reproducibility of exposure was high : the between-day within-subject coefficients of variation for total systemic exposure ( area under the serum insulin glargine concentration time curve from time 0 to 24h after dosing ) and maximum insulin concentration were 17.4 % [ 95 % confidence interval ( CI ) 15-21 ] and 33.4 % ( 95 % CI 28-41 ) , respectively .