Nearly 40% of new chemical entries are poorly water-soluble. Drug encapsulation into water-soluble polymers is an active research area owing to the ability of improving drug dissolution and absorption.Many processes can be used to produce drug molecular dispersions in polymers; principally fusion via melting and solvent evaporation. No studies have been performed comparing the efficacy of these two methods for the same polymer-drug combination.In our work, felodipine, a calcium channel blocker, and Eudragit E OP and PVP have been used as the model poorly water-soluble drug and carrier polymers, respectively. We propose neutron reflectivity to study the phase separation behaviour of spin-cast polymer-drug thin films,which will give us crucial information about the structure of the films in order to compare with the extruded dispersions,and the optimal processing for drug delivery systems.