Preparation of ultrafine fenofibrate powder by solidification process from emulsion

The solidification process from emulsion, which consisted of emulsifier, water and molten drug as oil phase without use of any organic solvent, was firstly employed to prepare ultrafine fenofibrate (FF) powder. The effects of stirring speed and volume ratios of hot emulsion to cold water on the particle size and morphology were discussed as well as the impacts of different emulsifiers on emulsion. The produced ultrafine powder was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, specific surface area analysis and a dissolution test. XRD patterns and FT-IR spectra showed that the ultrafine FF was crystalline powder with the structure and the components similar to those of bulk drug. The product had a mean particle size of about 3 μm with a narrow distribution from 1 μm to 5 μm. The specific surface area reached up to 6.23 m2/g, which was about 25 folds as large as that of bulk FF. In the dissolution tests, about 96.1% of ultrafine FF was dissolved after 120 min, while there was only 38.1% of bulk drug dissolved, proving that the dissolution property of ultrafine FF was significantly improved when compared to commercial drug.