ascorbate has demonstrated skin lightening effects18 and antioxidant
benefits, as well as protective effects in the presence of UVA radiation.19 In addition, vitamin E was incorporated into the moisturizer for further antioxidant benefits. The anti-aging moisturizer with 30% vitamin C also contained coenzyme Q10, which has multiple known topical benefits including antioxidant,
energizing, and wrinkle inhibitory effects.20,21
The test products containing these ingredients with known topical
benefits should produce a statistically significant anti-aging result in this single-center clinical usage study.
This single-center study was conducted in order to assess the efficacy and tolerance of a dual-product regimen containing a 0.5% retinol treatment and an anti-aging moisturizer with 30% vitamin C when used over the course of 12 weeks by women with mild-to-moderate facial hyperpigmentation and photodamage.
Clinical efficacy parameters included the following: 1) clarity/brightness; 2) fine lines; 3) evenness of skin tone (redness);
4) firmness; 5) global hyperpigmentation (mottled); 6) global hyperpigmentation (discrete); 7) overall photodamage; 8) radiance; 9) skin tone (color) evenness; 10) tactile smoothness; 11) visual smoothness; and 12) wrinkles. Tolerability parameters assessed included: erythema, dryness, scaling, burning, stinging,
and itching. In addition, users completed self-assessment questionnaires to evaluate product efficacy and attributes.
MATERIALS AND METHODS
The efficacy and tolerance of the dual product regimen was assessed
via clinical grading at baseline and at weeks 4, 8, and 12. Imaging procedures and self-assessment questionnaires were completed at these same timepoints.
The dual product regimen included a 0.5% retinol treatment and an anti-aging moisturizer with 30% vitamin C (containing
30% vitamin C in the form of THD ascorbate). In addition to encapsulated retinol, the 0.5% retinol treatment contained bakuchiol, and Ophiopogon japonicus root extract. In addition to the 30% THD ascorbate, the anti-aging moisturizer with 30% vitamin C also contained vitamin E and coenzyme Q10.
A total of 44 subjects (the per-protocol population) completed the 12-week clinical usage study. The demographic information is shown in Figure 1. Qualified subjects were between 35 to 60 years of age and exhibited mild-to-moderate global face hyperpigmentation
and global face photodamage. Patients were not eligible if they had known allergies to facial skin care products, retinol products, moisturizers, or sunscreens, or if they were using
any of several facial medications prior to study initiation.
Enrolled subjects were instructed to avoid application of any topical moisturizing products to the face for at least 2 days
prior to the baseline visit. At the baseline visit they were then instructed to apply the anti-aging moisturizer with 30% vitamin C to the entire face once per day in the morning after cleansing.
For the first 2 weeks of the study, subjects were instructed to apply the 0.5% retinol treatment every other evening to the entire face; subsequently, after the initial 2-week time period, they were instructed to apply the treatment every evening (or every other evening if irritation occurred). A basic sunscreen, Neutrogena UltraSheer® SPF 30, was instructed to be applied to the entire face if sun exposure was expected to occur for greater then 30 minutes for that day. Concerning study visits at the selected timepoints, subjects were instructed to remove all makeup at least 30 minutes prior to each scheduled clinic visit and to avoid applying other topical products to the face or eye area until after the visit.
Subjects were asked to avoid extended periods of sun exposure and all use of tanning beds for the study duration. In addition, they were instructed to wear protective clothing, including sunglasses,
and to avoid sun exposure between 10 AM and 2 PM. They were asked to continue use of all regular brands of color cosmetics
and makeup remover, but to avoid using any anti-aging products and beginning the use of any new facial products.
Clinical grading of efficacy parameters was performed at baseline
and weeks 4, 8, and 12. The parameters were assessed globally using a modified Griffiths’ 10-point scale22 according to the following numeric definitions (half-point scores were used as necessary to improve accuracy of assessment): 0 = none (best possible condition); 1-3 = mild; 4-6 = moderate; and 7-9 = severe (worst possible condition). Figure 2 describes the parameters
and possible assessment outcomes.
Tolerability evaluations were performed at baseline and weeks 4, 8, and 12 by assessing for signs and symptoms of erythema, dryness, and scaling, and by subject reporting of the degree of burning, stinging, and itching on the treatment area. For assessments
of subjective irritation, subjects reported the degree of any parameters that they typically experienced when using a product similar to the test material(s) at the baseline visit. At post-baseline timepoints, subjects reported the degree of any of these symptoms
they had experienced since the previous timepoint.
Digital photography was used to document each subject’s condition using the VISIA CR photo-station (Canfield Imaging Systems, Fairfield, New Jersey) with a Canon Mark II 5D digital
SLR camera (Canon Incorporated, Tokyo, Japan). A total of 3 full-face images were taken of each subjects (right side, left side, and center view).
Subjects completed a self-assessment questionnaire on facial skin condition, product efficacy, and product aesthetics at baseline
and at weeks 4, 8, and 12.