JADE Student Edition 2019 JADE JSLUG 2019 | Page 78

The role of ethnicity on percutaneous absorption Article #11 Abstract The role of ethnicity on percutaneous absorption The world encompasses many different skin ethnicities; one important factor that contributes to this variation is pigmentation. Questions have been raised whether there are any differences in the skin structure and barrier function of pigmented individuals and those that lack. Understanding the differences in skin structure of different ethnicities can play an important role in tailoring the use of cosmetics and therapeutic products to maximize treatment options for patients. This review article will look at the differences in the skin structure and barrier function of Caucasian, Black, Hispanic, and Asian skin; but mostly emphasizing on the differences between Caucasian and Black skin. Author: Murielle Nsiela Keywords: Skin ethnicity, stratum corneum, pigmentation, drug absorption Keywords: Skin ethnicity, stratum corneum, pigmentation, drug absorption Introduction Skin Physiology The largest organ in the body is the skin, it makes up 16% of one’s body mass and provides a protective barrier against the loss of important physiological components, it shields the body from pathogens, toxic agents and ultraviolet radiation (Sahle et al., 2015). The skin itself is sectioned into three main layers; the epidermis, which is the uppermost layer of the skin, and is in contact with the environment. This is followed by the dermis the thickest layer containing structures such as the hair follicles and sweat glands. The hypodermis is the innermost layer that includes adipose tissue for subcutaneous fat storage; this is essential in the skin’s thermal barrier and provides a mechanical cushion. Additionally, this layer contains most of the skins blood vessels and nerves (D’Orazio et al., 2013). The epidermis is further divided into five layers as illustrated in figure 1, the stratum corneum (SC), stratum lucidum (SL), stratum granulosum (SG), stratum spinosum (SS) and the stratum basale (SB) (Wickett and Visscher, 2006). 78