Kumud Madan, Sanju Nanda
Our skin is constantly subjected to various harmful environmental factors including particulate matter, nitrogen dioxide, ozone, and UV radiations leading to photoaging, photoimmunosupression and photocarcinogenesis encouraging photoprotection. Solid Lipid Nanoparticles (SLNs) have gained particular prominence in the field of photoprotection. SLNs are biodegradable, biocompatible colloidal systems with particle sizes typically ranging from 1 to 1000 nm. Owing to their intrinsic light-scattering properties, SLNs exhibit notable photoprotective effects, which are further enhanced when combined with conventional sunscreen agents, resulting in a synergistic improvement in efficacy. Beyond superior photoprotection, SLNs offer several additional advantages, including enhanced photostability, strong adhesiveness, favorable viscoelastic properties, and the capacity for controlled drug release. Their compatibility with a diverse range of sunscreen compounds underscores their versatility as a lipidic carrier system. This review consolidates the various benefits of incorporating molecular sunscreens into the lipidic matrix of SLNs, while also addressing their limitations, safety considerations, patentability, and regulatory perspectives. The combination of cosmetic attributes with multifunctional photoprotective effects makes SLNs highly suitable for the development of next-generation sunscreen formulations, particularly when enriched with natural bioactive agents.