Sustained-release ethyl cellulose (EC) micro-particles were prepared by electrospraying. Ketoprofen (KET) was taken as a model drug and various concentrations of EC functioned as a rate-controlling polymer. The morphology of the micro-particles was assessed using SEM. Images showed that as EC content increased, the granules shared similar surface characteristics containing pure EC. Micro-particle structures were analyzed by DSC, XRD, and FTIR. It was noted that the crystalline drug was converted into an amorphous form in all the granulations and that there was chemical interaction between KET and EC observed from FTIR. Dissolution studies revealed that as the amount of EC increased, the drug release rate decreased. This investigation suggests that electrospraying can be exploited as a useful tool for developing novel particulate drug delivery systems.