[The effect of urea on epidermal cell renewal measured with a noninvasive method]

On five subjects (2 women and 3 men) the penetration-promoting and cell division-blocking effect of 10% urea was measured and compared to that of the ointment base and a commercially available preparation (containing 10% urea, 5% lactic acid, and 4.3% betaine = ULB cream). The dansylchloride fluorescence detection technique coupled with quantitative evaluation on the lower arm was applied. Only ULB cream promoted penetration as early as day 3 and significantly increased fluorescence by day 6 as compared with controls.