This probably reflects a small increase in hydration of the skin surface during the time
between baseline reading and the one-hour reading, in spite of the 20-minute equilibration
time prior to measurement. The fact that it was seen only with the Nova © and
the Skicon © agrees with the observation of Clarys eta/. (11) that the Nova © and Skicon ©
are more sensitive to changes at the very surface of the skin than is the Corneometer ©.
For the 3% NaC1 and 0% glycerin formulation, the one- and two-hour readings with the
Nova © DPM were significantly different from baseline, whereas the readings with the
Skicon © and the Corneometer © were not significantly different from baseline.
The correlation between the instrumental reading and the glycerin concentration was
calculated and plotted for all three devices at each salt level (Figure 1). Strong linear