Efficacy of Pseudo-Ceramide Absorption Into the Stratum Corneum and Effects on Transepidermal Water Loss and the Ceramide Profile: A Randomized Controlled Trial.

Background: Changes in the level or profile of ceramides are associated with decreased stratum corneum (SC) barrier function. Topical application of a pseudo-ceramide (pCer)-containing moisturizer can improve barrier function. Additionally, pCer that absorbs into the SC may improve ceramide profiles.

Aim: We investigated the relationship between pCer absorption into the SC and SC properties and determined the efficacy of a pCer-containing spray compared with that of a commercial spray without pCer.

Patients/methods: Patients with self-perceived dry and sensitive skin and decreased barrier function (transepidermal water loss [TEWL] > 10 g/m²h) were randomized into two groups to topically apply a pCer-containing spray (test group; N = 33) or commercial spray without pCer (control group; N = 19) twice daily as a single-blind study. SC function and ceramide properties were investigated before and after 4 weeks of application.

Results: In the test group, the ceramide (NP)/(NS) ratio proportionally increased with the pCer application level after 4 weeks of pCer-containing spray application. In the control group, there were no changes in SC function after topical application of the commercially available spray without pCer; however, the SC water content, TEWL, SC cell area, and scaling score improved in the test group. Furthermore, the changes in TEWL in the test group were significantly negatively correlated with the pCer application level.

Conclusions: The efficacy of pCer-containing sprays for those who have sensitive skin with impaired barrier function was demonstrated. Furthermore, the improvement in SC barrier function induced by pCer may contribute to normalizing the SC ceramide profile.