After 4 weeks of daily use, 92% of participants showed an improvement in skin hydration.
The use of sunscreen is necessary to prevent sun damage, but the effect of sunscreen on the skin barrier function has not been greatly investigated. Researchers conducted a study of 60 Chinese women and found that daily application of ceramide-containing sunscreen increased skin hydration and improved the function of the skin barrier.1
The treatment sunscreen contained the UV filters 3% avobenzone, 10% homosalate, 5% octisalate, 2.7% octocrylene, and ceramide 1,3,6. Skin parameters were measured in a single-blinded method at baseline and again at weeks 1 and 4.
Cao et al used IPP software to examine the a* values of the right or left cheek area of interest (AOI) in the RBX-Red Illumination mode side view images of each participant through Tewameter measurements, Mexameter measurements, and Corenometer measurements.
At week 1, skin redness decreased by 10.96% as measured by the a* value, with 82% of participants showing improvement. After 4 weeks of product use, skin redness decreased significantly by 11.89% and 87% of participants showed improvement. “Our research shows that the decrease in erythema is significant compared to before use, indicating that the use of ceramide-containing sunscreen not only avoids skin irritation but also has potential anti-inflammatory abilities.”
There was a significant reduction in skin hemoglobin content of 5.63% at week 1 and 5.68% at week 4. By week 4, 83% of participants showed a reduction in skin hemoglobin content.
At week 1, there was no significant decrease in transepidermal water loss (TEWL) but 57% of participants showed improvement. At week 4, TEWL decreased by 22.96% and 97% of participants exhibited improvement.
Skin hydration also improved. At week 1, there was an increase of 15.34% in moisture content of the stratum corneum, and 92% of participants showed improvement. After 4 weeks of product use, moisture content increased 21.96%, and 97% of participants exhibited improvement.
Cao et al concluded that daily use of ceramide-containing sunscreen can improve skin hydration and the skin function of the skin barrier. The limitations of the study included the limited sample size and no assessment of molecular levels.