It is estimated that > 40% of new drug molecules are poorly water soluble. Although there are many options for improving aqueous solubility, few if any, achieve the required level of solubility. For many reasons, solubilisation in nonionic surfactant micelles is a favoured means of increasing apparent aqueous solubility. Recently our group has found that significant increases in drug solubilisation can be achieved by ‘matching' the hydrophobe of the surfactant to the drug structure. In particular, we found that the drug, ibuprofen, is solubilised extremely well in micelles formed by the nonionic surfactant, Triton X-100, which has a hydrophobe which closely matches the structure of ibuprofen. The aim of the proposed SANS study is to understand the nature of the incorporation of the drug ibuprofen into Triton X-100 micelles in order to aid our rational design of new, improved surfactants.