Sunscreens: A comprehensive review with the application of nanotechnology

Ultraviolet (UV) radiation is the primary cause of various skin diseases, necessitating the need for UV protection. Topical sunscreens are the most commonly used method to achieve this. However, traditional sunscreen formulations have limitations that hinder their widespread use. Nanotechnology has played a significant role in the development of new sunscreen formulations that aim to address the limitations of traditional sunscreens. These advancements have brought about several improvements in terms of UV protection and cosmetic appeal. The review explores different nanosystems utilized in sunscreen formulations, including polymeric nanoparticles, liposomes, nanostructure lipid carriers, solid lipid nanoparticles, nanoemulsions, hydrogels, nanocrystals, mesoporous silica particles, niosomes, ethosomes, transfersomes, transethosomes, and sunspheres. These nanosystems enhance the safety and effectiveness of sunscreens, improving their distribution, photostability, SPF, UVA protection, and water resistance. Combinational sunscreens, which combine multiple active ingredients, are also discussed. They offer broad-spectrum protection against UVA and UVB radiation, providing comprehensive sun protection. The article reviews evaluation methods for sunscreens, such as SPF, UVA protection, and water resistance. SPF measures the level of UVB protection, while UVA protection indicates defense against UVA radiation. Water resistance assesses the sunscreen's durability after exposure to water or sweat. Additionally, the article addresses the safety, regulation, and challenges associated with nanosystem-based sunscreens. Safety considerations and regulatory frameworks ensure the products' safety for human health and the environment. Formulation stability, potential toxicity concerns, and lack of public awareness are also discussed as challenges. In summary, nanotechnology-based sunscreens offer promising advancements in UV protection. The utilization of various nanosystems improves safety and efficacy. Ongoing research and regulatory efforts are vital to ensure the continued development and safe use of these nanosystems in sunscreens.