The Influencing Factors of the Impermeability of Water-resistant and Sun-protective Agents and Their Action Pathways

Abstract

Water-resistant sunscreens block ultraviolet rays through the construction of physical barriers and the synergistic effect of chemicals. Their anti-seepage performance is influenced by multiple factors such as the characteristics of film-forming agents, the compatibility of sunscreens, environmental conditions, and the physiological state of the skin. This article systematically reviews the molecular structure and film-forming mechanism of anti-water film-forming agents, analyzes the interaction pathways between physical and chemical sunscreens, reveals the destructive mechanisms of environmental factors such as humidity, temperature, and friction on the stability of the film layer, and explores the correlation between skin barrier function and the penetration of sunscreens. Research indicates that optimizing the molecular weight of film-forming agents, regulating the compounding ratio of sunscreens, and improving the hydrophilic and lipophilic balance value (HLB) of the formula are the key paths to enhance the efficacy of water-resistant sunscreens, providing a theoretical basis for the development of highly efficient and long-lasting sunscreen products.