7. MOISTURISING EFFECT The moisturising effect of Sanisara W was determined by evaluating the water-holding capacity of the stratum corneum, the outermost layer of the skin. The test performed was a water sorption-desorption test.
Test areas (1 × 1 cm for each test sample) were chosen from the inner side of the forearm of 9 healthy subjects.
Distilled water (100 µL ) was applied onto each test area. After 30 seconds, the water was wiped off with a paper towel, followed by measurement of skin capacitance using Corneometer CM825 (Courage+Khazaka electronic GmbH). The measurement was continued after 60, 90, and 120 seconds.
After the initial steps, each test sample (Sanisara W and 3 other brands) was then applied to the test areas using cotton swabs. This procedure was repeated 12 times in 5-minute intervals. As for the control, no test sample was applied to the test areas.
The test areas were washed 30 minutes after the last application. The process of measuring skin capacitance starting with applying DW onto each test area up to measuring capacitance at the specific time intervals (30, 60, 90, and 120 seconds) was performed again.
The water-holding capacity of the stratum corneum and the percentage change were determined using the following formulas: