Clinical Evaluation of a Thiamidol-containing Regimen Compared With Photoprotection for the Visual Management of Facial Hyperpigmentation

Abstract

Objective: Pigmentary disorders, including melasma, post-inflammatory hyperpigmentation, and solar lentigines, are among the most common skin disorders. Uneven skin tone as a result of hyperpigmentation affects how patients see themselves, and how they are perceived by others, resulting in an impact on patients’ quality of life. Photoprotection in the form of broad-spectrum ultraviolet sunscreen is the cornerstone of most standard management protocols to reduce hyperpigmentation exacerbation. Hyperpigmentation is mediated by overactivity of a multi-step synthesis process resulting in the overproduction of melanin from tyrosine via tyrosinase activity. Recently, isobutylamido thiazolyl resorcinol (Thiamidol) has been identified as the most effective human tyrosinase inhibitor out of >50,000 screened compounds, making it an attractive ingredient for anti-hyperpigmentation formulations. The objective of this study was to evaluate the efficacy of a Thiamidol-containing regimen (Day Lotion with SPF 30, Serum, and Night Cream) compared with a standard SPF 30 lotion for visible management of hyperpigmentation.

Materials and Methods: A randomized study was performed (N=95; n=47, Thiamidol regimen; n=48, standard SPF 30 lotion) with subjects aged 18-64 and Fitzpatrick Skin Types I-VI clinically presenting with facial hyperpigmentation (measured by colorimeter and individual typology angle [ITA°]) to assess the efficacy of the Thiamidol-containing regimen (Day Lotion with SPF 30 and Serum applied in the morning, Night Cream and Serum applied in the evening) compared with a standard SPF 30 lotion (applied 1-4 times daily as needed) for 12 weeks, followed by a 6-week regression phase.

Results: Facial hyperpigmentation, measured by skin lightness, ITA° values, radiance and shine, was significantly reduced relative to baseline for both groups as early as Week 2, and significantly reduced for patients receiving the Thiamidol-containing regimen vs the standard SPF 30 lotion at Weeks 8 and 12. Additionally, both groups maintained significant reductions in hyperpigmentation compared to baseline after a 6-week regression phase.

Discussion: This study demonstrates that while SPF alone can reduce the visible signs of hyperpigmentation, the addition of Thiamidol to a daily skin care regimen can confer additional benefit with regard to skin lightness, radiance, and shine. This data supports the integration of Thiamidol-containing formulations into existing skin care regimens for individuals with facial hyperpigmentation.

Scientific Poster support provided by Beiersdorf, Inc.