METHODS
60 female subjects Fitzpatrick skin types I–V age 40–65 years were enrolled in a 4-week single site study after completing informed consent (Allendale Institutional Review Board, Old Lyme, CT) and meeting all inclusion criteria and none of the exclusion criteria. Subjects possessed mild to moderate photodamaged skin defined as the presence of wrinkles and uneven skin tone rated 3–6 on the Fitzpatrick Wrinkle and Elastosis Scale.9 In addition, the subjects possessed self-perceived sensitive skin. The sensitive skin panel was constructed according the following guidelines: 1/3 eczema/atopic dermatitis, 1/3 rosacea, and 1/3 cosmetic intolerance syndrome. All subjects washed out of anti-aging or therapeutic skin care products for 4 weeks prior to study entry and topical retinoids or AHAs for 3 months prior to study enrollment.
Subjects were not allowed to consume anti-inflammatory drugs, immunosuppressives, or anticancer medications. Subjects were dispensed a compliance diary, cleanser, and anti-aging moisturizer with the first application occurring at the research center. Study products were applied morning and evening to the face and neck. Investigator tolerability (investigator assessed erythema/redness, peeling/flaking, visual roughness, dryness and subject queried stinging, burning, itching, tightness) and subject tolerability (stinging, burning, itching, tightness, redness, flaking, roughness, irritation, dryness, overall sensitivity) assessments were performed on a 5-point ordinal scale (0=none, 1=minimal, 2=mild, 3=moderate, 4=severe). Investigator and subject efficacy assessments (visual smoothness, tactile softness, clarity, radiance, overall skin appearance, overall global photoaging) were also conducted on the same 5-point ordinal scale. All evaluations were repeated at week 4.
Instrumental noninvasive upper right cheek transepidermal water loss (TEWL)(Evaporimeter, Cyberderm, Broomall, PA) and lower right cheek triplicate pin probe corneometry (Dermalab Combo, Cortex Technologies, Hadsund, Denmark) measurements were recorded after subjects acclimated to the research center environment for 30 minutes. Measurements were obtained at baseline, 5–10 minutes post-application, and week 4.
Subjects were not allowed to consume anti-inflammatory drugs, immunosuppressives, or anticancer medications. Subjects were dispensed a compliance diary, cleanser, and anti-aging moisturizer with the first application occurring at the research center. Study products were applied morning and evening to the face and neck. Investigator tolerability (investigator assessed erythema/redness, peeling/flaking, visual roughness, dryness and subject queried stinging, burning, itching, tightness) and subject tolerability (stinging, burning, itching, tightness, redness, flaking, roughness, irritation, dryness, overall sensitivity) assessments were performed on a 5-point ordinal scale (0=none, 1=minimal, 2=mild, 3=moderate, 4=severe). Investigator and subject efficacy assessments (visual smoothness, tactile softness, clarity, radiance, overall skin appearance, overall global photoaging) were also conducted on the same 5-point ordinal scale. All evaluations were repeated at week 4.
Instrumental noninvasive upper right cheek transepidermal water loss (TEWL)(Evaporimeter, Cyberderm, Broomall, PA) and lower right cheek triplicate pin probe corneometry (Dermalab Combo, Cortex Technologies, Hadsund, Denmark) measurements were recorded after subjects acclimated to the research center environment for 30 minutes. Measurements were obtained at baseline, 5–10 minutes post-application, and week 4.
RESULTS
60/60 subjects successfully completed the study. The investigator rated no tolerability issues and highly statistically significant improvement (P<0.001) in all parameters to include visual smoothness, tactile smoothness, clarity, radiance, overall appearance, and global anti-aging (Figure 1).
The subject ratings mirrored the investigator assessments with highly statistically significant improvement (P<0.001) in visual smoothness, tactile smoothness, clarity, radiance, overall
appearance, and global anti-aging. The subjects assessed tolerability in terms of stinging, burning, itching, and tightness. In 10% of subjects primarily with eczema, minimal stinging occurred immediately after application (P=0.008) and persisted into week 4 (P=0.031). A few subjects noted minimal tightness at week 4 (P=0.017). Overall, the subject assessed tolerability profile was excellent given the sensitive skin panel composed of subjects with eczema, rosacea, and cosmetic intolerance syndrome.
TEWL readings did not change from baseline to week 4 indicating absence of barrier damage in sensitive skin subjects, which is crucial to skin health in this population. Corneometry triplicate measurements were taken from the cheek of all subjects. The skin care products produced a highly statistically significant 16% increase in skin moisture content (P<0.001), which is notable given the challenging sensitive skin population enrolled in the study.
The subject ratings mirrored the investigator assessments with highly statistically significant improvement (P<0.001) in visual smoothness, tactile smoothness, clarity, radiance, overall
appearance, and global anti-aging. The subjects assessed tolerability in terms of stinging, burning, itching, and tightness. In 10% of subjects primarily with eczema, minimal stinging occurred immediately after application (P=0.008) and persisted into week 4 (P=0.031). A few subjects noted minimal tightness at week 4 (P=0.017). Overall, the subject assessed tolerability profile was excellent given the sensitive skin panel composed of subjects with eczema, rosacea, and cosmetic intolerance syndrome.
TEWL readings did not change from baseline to week 4 indicating absence of barrier damage in sensitive skin subjects, which is crucial to skin health in this population. Corneometry triplicate measurements were taken from the cheek of all subjects. The skin care products produced a highly statistically significant 16% increase in skin moisture content (P<0.001), which is notable given the challenging sensitive skin population enrolled in the study.
DISCUSSION
The search for cosmeceutical ingredients suitable for use in patients with sensitive skin resulted in the development of a bakuchiol-based cleanser and moisturizer. Bakuchiol has been studied as an antioxidant for its ability to interfere with free radical-producing systems, inhibit microsomal lipid peroxidation, decrease translocation of mitochondrial apoptosis induced factor (AIF), and quench superoxide- and hydroxy- radicals in vitro.10,11 It also can inhibit matrix metalloprotease (MMP) MMP-1 more effectively than retinol.12 Even though bakuchiol can function like retinol in the regulation of gene
