We request 6 days on NIMROD to collect total scattering neutron diffraction data of aqueous solutions of paracetamol and caffeine. While much effort has gone into improving the physciochemical properties of drugs in their solid forms, less attention has been paid to the the nature of interactions of drug molecules in solution. By using a neutron spallation source together with isotopic subsitution and empirical structure refinement procedures it is possible to determine intermolecular structure correlations in solution. These data will provide a detailed insight into the environment of the solute and solvent molecules and enable determination of the role of hydrogen bonding and ring-ring interactions in directing the solvation and self assembly of pharmaceutical molecules in solution.