Influence of different surfactants on the technological properties and in vivo ocular tolerability of lipid nanoparticles

Addition of one or more surfactant agents is often necessary for the production of nanostructured lipid and polymeric systems. The removal of residual surfactants is a required step for technological and toxicological reasons, especially for peculiar applications, such as the ophthalmic field. This study was planned to assess the technological properties of some surfactants, commonly used for the production of lipid nanoparticles, as well as their ocular safety profile. Stable and small-size solid lipid nanoparticles were obtained using Dynasan® 114 as the lipid matrix and all the tested surfactants. However, from a toxicological point of view, the nanocarriers produced using Kolliphor® P188 were the most valuable, showing no irritant effect on the ocular surface up to the highest tested surfactant concentration (0.4%, w/v). The SLN produced using Cremophor® A25 and Lipoid® S100 were tolerated up to a surfactant concentration of 0.2% by weight, while for Tween® 80 and Kolliphor® HS 15 a maximum concentration of 0.05% can be considered totally not-irritant.