Nanoemulsions (NE) i.e. nanoparticles containing a fluid lipid or oil dispersed in water and stabilized by a surfactant particles have attracted considerable attention as vehicles for the delivery of poorly-water soluble drugs. Recent studies have surprisingly shown that in certain types of NE increasing the amount of lipid present has a detrimental effect on the solubility of drug. The proposed study will use SANS in combination with contrast variation to probe the internal structure of NE containing high amounts of lipid understand the reason for the fall in drug solubilisation in these systems. The insight provided by the study should provide an understanding of the potential of NE as vehicles for drug delivery.