© 2005 Blackwell Publishing • Journal of Cosmetic Dermatology, 4, 167–173 167 Original Contributions Blackwell Publishing, Ltd. Clinical efficacy assessment in photodamaged skin of 0.5% and 1.0% idebenone DH McDaniel, 1 BA Neudecker, 2 JC DiNardo, 3 JA Lewis II, 3 & HI Maibach 1 Institute of Anti-Aging Research, Eastern Virginia Medical School, Norfolk, VA 2 Department of Dermatology, University of California Son Francisco, San Francisco, CA 3 Pharma Cosmetix Research, LLC, Richmond, VA Summary Idebenone is an antioxidant lower molecular weight analogue of coenzyme Q10. Previously, idebenone was shown to be a very effective antioxidant in its ability to protect against cell damage from oxidative stress in a variety of biochemical, cell biological, and in vivo methods, including its ability to suppress sunburn cell (SBC) formation in living skin. However, no clinical studies have been previously conducted to establish the efficacy of idebenone in a topical skincare formulation for the treatment of photodamaged skin. In this nonvehicle control study, 0.5% and 1.0% idebenone commercial formulations were evaluated in a clinical trial for topical safety and efficacy in photodamaged skin. Forty-one female subjects, aged 30–65, with moderate photodamaged skin were randomized to use a blind labelled (either 0.5% or 1.0% idebenone in otherwise identical lotion bases) skincare preparation twice daily for six weeks. Blinded expert grader assessments for skin roughness/dryness, fine lines/wrinkles, and global improvement in photodamage were performed at baseline, three weeks and six weeks. Electrical conductance readings for skin surface hydration and 35 mm digital photography were made at baseline after six weeks. Punch biopsies were taken from randomly selected subjects, baseline and after six weeks, and stained for certain antibodies (interleukin IL-6, interleukin IL-1b, matrixmetallopro- teinase MMP-1, collagen I) using immunofluorescence microscopy. After six weeks’ use of the 1.0% idebenone formula, a 26% reduction in skin roughness/dryness was observed, a 37% increase in skin hydration, a 29% reduction in fine lines/wrinkles, and a 33% improve- ment in overall global assessment of photodamaged skin. For the 0.5% idebenone formulation, a 23% reduction in skin roughness/dryness was observed, a 37% increase in skin hydration, a 27% reduction in fine lines/wrinkles, and a 30% improvement in overall global assessment of photodamaged skin. The immunofluorescence staining revealed a decrease in IL-1b, IL-6, and MMP-1 and an increase in collagen I for both concentrations. Keywords : antioxidant, idebenone, photodamage Introduction Antioxidants have become popular anti-aging ingredients in topical skincare products. Antioxidants have been shown to be photoprotective, anti-inflammatory, able to reduce UVR-induced immunosuppression, and protective against free radical–mediated cellular damage. 1 Typically these ingredients have been referred to as agents that Correspondence: D. H. McDaniel, MD, Institute of Anti-Aging Research, 933 First Colonial Road Suite 113, Virginia Beach, Virginia 23454, E-mail: mjohnson@lsvcv.com Accepted for publication June 25, 2005