Sunscreen Efficacy Validation and Other Topics

Skin and Skin
Care pH on epidermal permeability: Hachem et al. have studied the effect of pH on epidermal permeability and skin barrier homeostasis.¹ Although the skin has long been known to display an acid surface, known as an “acid mantle,” little is known about either the origin or the function of this acidic surface. Prior students of the acid mantle ascribed its origin principally to exogenous sources of microbial, sebaceous gland and/or eccrine gland origin^.2 Recent studies support alternative views of the origin of the acid mantel, as well as additional functions of the stratum corneum (SC).^3-5