AUTHOR=Salminen Alec T. , Manga Prashiela , Camacho Luísa 

TITLE=Race, pigmentation, and the human skin barrier—considerations for dermal absorption studies

JOURNAL=Frontiers in Toxicology

VOLUME=Volume 5 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/toxicology/articles/10.3389/ftox.2023.1271833

DOI=10.3389/ftox.2023.1271833

ISSN=2673-3080

ABSTRACT=A functional human skin barrier is critical in limiting harmful exposures to environmental agents and absorption of intentionally applied topical drug and cosmetic products. Inherent differences in skin barrier between consumers due to extrinsic and intrinsic factors are an important consideration in the safety assessment of dermatological products. Race is a concept often used to describe a group of people who share distinct physical characteristics. The observed predisposition of specific racial groups to certain skin pathologies highlights the potential differences in skin physiology between groups. In the context of the human skin barrier, however, current data correlating function to race often conflict. These differing results are likely a consequence of the range of experimental approaches and controls employed in existing works. To date, a variety of methods have been developed for evaluating compound permeation through human skin, both in vivo and in vitro. Additionally, great strides have been made in the development of reconstructed human pigmented skin models, with the flexibility to incorporate melanocytes from donors of different race and pigmentation levels. Together, the advances in the production of reconstructed human skin models and the increased adoption of in vitro methodologies have the potential to aid in the standardization of dermal absorption studies for discerning racial and skin pigmentation differences in human skin barrier. This review analyzes the existing data on skin permeation, focusing on its interaction with race and skin pigmentation, and highlights the tools and research opportunities to represent better the diversity of human populations in these assessments.