Bio-surfactants that can be harvested from micro-organisms are of particular interest, because these can potentially be harvested in high yield and at low cost. In this category of bio-surfactants, are the rhamnolipids that are produced by various forms of bacteria. Rhamnolipids not only show very low-toxicity and are bio-degradable, they can now be produced with high efficiency allowing for economical production and industrial scalability. These characteristics, together with their proven anti-fungal activity, makes them very promising candidates for use in manufacture of active drug delivery systems for drugs like amphotericin B. In the studies proposed here, we aim to carry out neutron reflectivity experiments to determine the structure of the AmB-containing monolayers formed at the air-water interface by rhamnolipid(/sterol) with and without AmB.