Micronization of gemfibrozil by reactive precipitation process.

Ultrafine gemfibrozil (GEM) was prepared by reactive precipitation process in which methyl cellulose (MC) was employed to inhibit the growth and the agglomeration of particles. The impact of NaOH concentrations on bulk GEM consumption was explored. The effects of H2SO4 concentrations and the drying methods on the particle size and morphology were also discussed. The produced ultrafine powders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, specific surface area analysis and dissolution test. XRD patterns and FT-IR spectra showed that the as-obtained ultrafine GEM was a crystalline powder with the structure and components similar to those of bulk GEM. The ultrafine GEM had a mean particle size of about 1.25 microm with a narrow distribution from 0.6 to 3 microm. The specific surface area reached up to 11.01 m2/g, which was about 6 times as large as that of bulk GEM. In the dissolution tests, about 91.2% of ultrafine GEM was dissolved after 120 min, while there was only 23.6% of bulk GEM dissolved, proving that the dissolution property of ultrafine GEM was significantly enhanced when compared to commercial GEM owing to a decreased particle size and an increased specific surface area.