Development of Nanostructured Lipid Carrier as Potential Sun Protectant

Aqueous dispersions of lipid nanoparticles are being investigated as drug delivery system for different therapeutic purpose. In the present investigation, aqueous dispersion of solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were prepared by ethanol injection method and then incorporated into the freshly prepared water removable cream base. Lipid nanoparticles were characterized for particle size, PDI, zeta potential and surface morphology. The optimized lipid nanoparticles bearing oxybenzone were incorporated into cream base and were evaluated for in vitro and in vivo parameters. Cream base formulations containing SLN and NLC with 5% oxybenzone equivalent showed slow drug permeation compared to cream base containing 5% oxybenzone solution. The cream base formulations containing oxybenzone loaded lipid nanoparticles had shown better sun protecting factor (SPF 21 for NLC & 24 for SLN) as compared to cream base formulation. The confocal laser scanning microscopy (CLSM) study shows higher retention of SLN in the subcutaneous skin as compare to NLC and plain cream base. Hence studies revealed the SLN exhibited good skin retention and sun protection effect as compared to NLC and plain cream based formulation.