The preparation and in vitro evaluation of titanium dioxide incorporated solid lipid nanoparticles

ABSTRACT Use of sunscreening preparations became absolutaly necessary after the attention had been given to the harmful effects of the sun rays. Efficacy and safety of the products must be maintained because of their frequent and long term usage. Emulsions, lotions, oils, gels, sprays and sticks are the most common formulation types of sunscreens. Besides those systems, solid lipid nanoparticles (SLN), which were determined to scatter and reflect UV rays, were evaluated as new delivery systems for sunscreening materials and researches have intensified on SLNs. Many research results showed synergistic UV protection effect after incorporation of the sunscreening materials into SLN formulations. With SLNs, there is a possibility of preparing more efficacious and safer formulations by decreasing the concentrations of the sunscreening agents, which may lead to serious side effects, without changing the sun protection factor. In this study, titanium dioxide incorporated SLN formulations prepared using both classical and novel incorporation methods were investigated by evaluating their stabilities and physicochemical characteristics. UV protection abilities of formulations were investigated using in vitro TransoreT and Sun To SeeT Test methods. Results have been discussed by comparing the classical SLN formulation with the novel SLN and the emulsion formulations. The results showed the superiority of the novel SLN formulations compared to the classical SLN; superiority of the SLN formulations compared to the emulsion formulations. Incorporation of titanium dioxide as a sunscreen agent into the SLN formulations gives opportunity to produce stable and safe formulations with high UV protection ability. Key Words : Solid Lipid Nanoparticles (SLN), Titanium Dioxide, TransoreT Test, Sun To SeeT Test u