The current project aims to probe (at the nanometer length scale) the relationship between the structure of a surfactant molecule, the micelles it forms in solution, and the drug molecules that its micelles can solubilise. Once obtained this understanding should allow the ration design of novel surfactant molecules to form micelles in which the drug loading is optimized. In the present study a series of structurally related steroidal drug molecules, namely 4-cholesten-3-one and adrenosterone will be solubilised in micelles formed from C12 surfactants with differing head groups. The results of the study will be complemented by molecular dynamic simulations of the drug in the surfactant micelles using the aggregation number obtained from SANS. The results of the study are essential to aiding the rational design and selection of surfactant micelles to optimise drug solubilisation.