In Vitro and In Vivo Efficacy and Tolerability of a Non-Hydroquinone, Multi-Action Skin Tone Correcting Cream

July 2019 | Volume 18 | Issue 7 | Original Article | 642 | Copyright © July 2019


Pearl E. Grimes MD,a David H. McDaniel MD,b Mitchell Wortzman PhD,c Diane Nelson RN MPHc

aVitiligo & Pigmentation Institute of Southern California, Los Angeles, CA

bMcDaniel Institute of Anti-Aging Research, Virginia Beach, VA

cskinbetter science LLC, Phoenix, AZ 

provement, 2=Mild Improvement, 3=Moderate Improvement, 4=Marked Improvement) at 4, 8, and 12 weeks. 

Melanin index measurements were obtained at baseline, 4, 8, and 12 weeks (Mexameter® MX 18, Courage+Khazaka Electronic GmbH, Germany). Standardized measurements were based on an average of 3 measurements obtained from the same location of a hyperpigmented area (an easily identifiable location or “spot”). Subjects completed a 21-question self-assessment at baseline, 4, 8, and 12 weeks. Evaluation of tolerability and collection of Adverse Events (AEs) occurred throughout the study period. 

All methods and procedures were identical in an optional 4-week extension study conducted through week 16. 

Statistical Analysis 

Endpoints were analyzed as mean least squares (LS) improvement and mean LS percent improvement from baseline to each timepoint. Global Improvement was analyzed based on the observed values. 


Mean percent improvement over time was based on the adjusted means (LS Means). Adjusted means were calculated using a general linear model, considering individual values at baseline for each variable. 

RESULTS

Subject Demographics and Disposition
A total of 52 subjects completed the study. Three subjects withdrew from the study and one subject was lost to follow-up. There were no significant differences between the two treatment groups. The majority of subjects in each treatment group presented with moderate dyschromia. Skin types I–V were represented in the study. All subjects continued using the product(s) through week 16.

Treatment Group 1 (ETCS, n=42) 

Twice daily application of ETCS demonstrated significant mean percent reductions from baseline in dyschromia at all timepoints (13% at 4 weeks, 24% at 8 weeks, and 31% at 12 weeks; P<0.0001, each) (Figure 1). Approximately half of the subjects (48%) achieved at least a ≥1-grade improvement in the appearance of dyschromia as early as 4 weeks. Significant mean percent reductions from baseline in melanin index were demonstrated in subjects at all timepoints (P<0.0001, each; Figure 2), with 7%, 12%, and 16% mean reductions from baseline at 4, 8, and 12 weeks, respectively. Additional parameters measured resulted in significant mean percent improvements from baseline in subjects at 12 weeks in the appearance of fine lines/wrinkles, pore size, and skin texture (Table 1; Figures 3 and 4). Subjects also experienced significant mean improvements in global improvement at 12 weeks (P<0.0001). 

At 16 weeks, subjects achieved significant mean percent reductions from baseline in dyschromia (37%; P<0.0001) and melanin index (19%; P<0.0001). Significant mean improvements from baseline were also visibly demonstrated in subjects for erythema (28%; P<0.006), skin texture (29%; P<0.0001), fine lines/ wrinkles (15%; P=0.0002) and pore size (16%; P=0.003).