Nanoemulsions as Vehicle for Topical 8-Methoxypsoralen Delivery

This work describes preparation, characterization and properties of nanoemulsion formulations as drug carrier systems for topical application of 8-methoxypsoralen (8-MOP). The lipid emulsions were prepared from soy bean oil, as oil phase, different mixtures of phospholipids as emulsifiers (soy phosphatidylcholine or hydrogenated soy phosphatidylcholine or soy lecithin), and a mixture water/glycerine as aqueous phase. To characterize the physicochemical properties of the lipid nanoemulsions, average diameter, polydispersity index and Zeta potential were determined. The effects of the nanoemulsion incorporation on the 8-MOP diffusion through and into the skin were investigated in vitro using newborn pig skin. Data showed that 8-MOP was predominantly localized in the different skin layers, with a minimal amount (less than 0.05% of the applied dose) detected in the receptor compartment.