Particle size is ones of the most important characteristic of active drug substance that affects solubility and bioavailability. Fenofibrate, as a class II drug based on biopharmaceutical classification system, which has poor aqueous solubility has been chosen to be drug model of particle size reduction.. Fenofibrate was mixed with mannitol as stabilizer with the ratio 1:9 in physical mixture form. The size reduction was conducted by a ball mills, with the milling rate of 100, 200 and 300 rpm, respectively. Characterization of the solid dispersion was analyzed by organoleptic and instrumental method. The instrumental tools used were Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) which showed that there was no changes happen in fenofibrate molecule during milling process. Scanning Electron Microscope results showed that fenofibrate-mannitol was produce non-spherical forms. Milling rate improvement produce smaller size of particle with rough morphology that decrease the flow properties. Based on the solubility test and reflected in UV/Vis spectra, it showed that particle size reduction with 200 rpm milling rate determined 3 times higher of aborsbance value compared with pure fenofibrate
