Development of NLC- based Sunscreen Gel of Lutein and its in-vitro and ex-vivo Characterisation

Background: In humans, Carotenoids are important in scavenging singlet oxygen and peroxyl radicals. Lutein has been demonstrated in multiple studies to help protect the skin from photodamage, as well as provide a variety of other health advantages. In the recent decade, the topical use of Lutein as a new ultraviolet (UV) protectant, anti-stress, and blue light filter capable of protecting skin from photodamage has piqued cosmetic and pharmacological attention. Because Lutein is insoluble, it was integrated into nanocarriers for topical administration. Objective: The objective of this study was to formulate an NLC-based sunscreen gel of Lutein. Methods: Nanostructured lipid carriers (NLC) were prepared by melt emulsion ultrafiltration technique and were evaluated for particle size, zeta potential, polydispersity index (PDI), drug loading (DL), encapsulation efficacy (EE), and in vitro drug release. The optimised formula was incorporated into a gel base and an in-vitro sun protection factor (SPF) was determined. Ex- vivo permeation study was performed on rat skin using a Franz diffusion cell. Cocoa butter and rose oil were chosen as solid and liquid lipids for NLC formulation. Results: The particle size, PDI, zeta potential, entrapment efficiency, and in vitro drug release of optimised formulation (NLC5) were found to be 81.64 nm, 0.463, -14.1mV, 79.90 %, and 89.86% respectively. The SPF value of the Lutein-NLC-loaded gel was found to be 27.524. The drug flux Jss from NLC gel was measured in the range of 0.07955 g/cm²/h. Conclusion: The investigation suggested lipid nanoparticles as a suitable carrier for Lutein to be delivered as sunscreen gel.