In Vitro and In Vivo Assessment of an Innovative Peeling System with Azelaic and Tranexamic Acids for Targeted Hyperpigmentation Reduction

Abstract

Introduction: Melanin, derived from tyrosine, plays a pivotal role in skin pigmentation through melanogenesis. Disruptions in this process lead to hyperpigmentation, a condition affecting skin tone and quality of life. Current treatments, including chemical peels, have limitations, highlighting the need for novel solutions. Here, we present an innovative peeling system, comprising a masque and moisturizer, formulated with a novel blend of acids, including azelaic acid (AZA) and tranexamic acid (TXA), alongside known brightening and penetration-enhancing agents for a comprehensive solution to target hyperpigmentation.

Methods: In vitro studies assessed the ability of the novel moisturizer to inhibit ultraviolet-A (UVA)-induced melanin accumulation in human melanocytes. In a single-center, controlled study, we assessed the efficacy of the peeling system in 33 healthy female participants aged 30-55 years with moderate-to-severe hyperpigmentation over a 6-week treatment period. Skin condition was assessed using clinical photography, 3D skin topography, and clinical expert evaluation (CEE) at baseline and 6 weeks post-treatment. Participants completed a self-evaluation questionnaire at 6 weeks post-treatment.

Results: In vitro findings demonstrated a concentration-dependent inhibition of melanin accumulation by the novel moisturizer. In vivo, significant reductions in dark spot number, area, and perimeter were observed at week 6, along with improvements in skin homogeneity, contrast, and brightness. Skin tone and roughness parameters also improved significantly from baseline. These findings were supported by self-evaluation findings and improvements in CEE parameters.

Conclusion: These data provide evidence for the efficacy of the innovative peeling system in reducing the appearance of hyperpigmentation over a 6-week treatment regimen in females with healthy skin and moderate-to-severe hyperpigmentation. The inclusion of AZA and TXA within the peeling system, along with active brightening and penetration-enhancing ingredients, may have synergistically facilitated the observed improvements. This multifaceted approach may address hyperpigmentation at the source, contributing to overall improvements in the appearance of the skin.

Keywords: Azelaic acid; Hyperpigmentation; Melanogenesis; Tranexamic acid.

Fig. 1

Timeline and treatment schedule

Fig. 2

Normalized cell viability levels in normal human epidermal melanocytes following application of a novel moisturizer at varying concentrations. **p < 0.01, ****p < 0.0001

Fig. 3

Normalized melanin levels in normal human epidermal melanocytes following application of a novel moisturizer at 0.0001% and 0.001% and UVA exposure. *p < 0.05, ****p < 0.0001. UVA ultraviolet-A

Fig. 4

Dark spot parameter mean change from baseline following 6 weeks of treatment with the innovative peeling system. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001

Fig. 5

Skin brightness mean change from baseline following 6 weeks of treatment with the innovative peeling system. ***p < 0.001

Fig. 6

Skin tone parameters mean change from baseline following 6 weeks of treatment with the innovative peeling system. ****p < 0.0001. CieL* lightness component of the CIELAB color space, CieA* green–red component of the CIELAB color space, CieB* blue–yellow component of the CIELAB color space, ITA, individual typology angle

Fig. 7

Skin roughness parameters mean change from baseline following 6 weeks of treatment with the innovative peeling system. **p < 0.01, ****p < 0.0001. Sa average value of all height points, St maximum height deviation on the surface, peak to peak, Stm average of the 25 local peak-to-peak values, Sq standard deviation of the height points, Sr ratio of the real developed area to the apparent area

Fig. 8

CEE parameters at baseline and following 6 weeks of treatment with the innovative peeling system. CEE scores ranged from 0 to 4 for assessments of dark spots and from 0 to 9 for assessments of lack of radiance and skin tone. **p < 0.01, ****p < 0.0001. CEE clinical expert evaluation

Fig. 9

Representative parallel-polarized light clinical photographs of differences in skin outcomes at baseline (left) versus following the innovative peeling system at week 6 (right). (i) An increase in skin luminosity, texture, and tone is noted at week 6. (ii) An even skin tone and improved overall skin luminosity are achieved. (iii) Notable luminosity improvements and even skin tone are present on the cheeks and chin at week 6. Slight variations in lighting occurred, primarily due to minor differences in participants' expressions or positioning, which influenced how the camera flash reflected on their faces

Fig. 10

Self-evaluation questionnaire outcomes following 6 weeks of treatment with the innovative peeling system