A newly synthesized photostable retinol derivative (retinyl N-formyl aspartamate) for photodamaged skin: Profilometric evaluation of 24-week study

Background: Retinol (vitamin A) is used in the cosmetics industry as an antiwrinkle agent. However, its photoinstability and skin irritation potential make it challenging to use in general cosmetic formulations. Objective. The aim of this study was to assess the efficacy of a newly synthesized photostable retinol derivative (retinyl N-formyl aspartamate) in patients with photodamaged skin. Retinyl N-formyl aspartamate is a newly synthesized retinol derivative with higher photostability, and a similar effect on collagenase expression level as retinol. Methods: In all, 29 Korean women (age range: 31-54 years), who were not pregnant, nursing, or undergoing any concurrent therapy, were enrolled in this study. A total of 24 patients completed a 24-week trial of retinyl N-formyl aspartamate twice daily on the left half of the face and a placebo on the right half of the face. A clinical evaluation, photographs, and silicone replicas of both crow's-feet areas were taken at baseline and at weeks 12, 20, and 24. Skin replicas were then analyzed using an optical profilometry technique. The standard wrinkle and roughness features were then calculated and statistically analyzed. The tolerance profile of the product was also clinically evaluated during the study. Results: The 24 women who completed this study showed more improvement on the left side of the crow's-feet area in terms of the signs of photodamage than on the right side according to both their own (P <.001) and the investigator's (P <.05) evaluations. These results were confirmed by skin replica analyses. The average roughness showed significant improvement (P <.001). The smoothness depth was improved, but this was not statistically significant. One patient noted burning and prickling sensations, and she withdrew during the study. Limitations: Pigmentation changes were not assessed, investigators were not blinded, and the study size was relatively small. Conclusion: In this small study retinyl N-formyl aspartamate applied on a photodamaged face twice daily was significantly more effective than a placebo without severe side effects.