Effect of cogrinding with various kinds of surfactants on the dissolution behavior of phenytoin.

The physicochemical properties of phenytoin (PHT) combined with various kinds of surfactants at 40 w/w % such as sodium lauryl sulfate (SLS), sodium deoxycholate (DCNa), and the sucrose ester of stearic acid (SE) by a cogrinding method were investigated by X-ray diffraction analysis, Fourier transformed infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), and dissolution kinetics in 2nd fluid (Japanese Pharmacopoeia XII, pH 6.8, 37 degrees C). All X-ray diffraction peak intensities of the coground mixtures were decreased by grinding, and the product with DCNa grinding for 3 h transformed into a noncrystalline solid, but the products with SE and SLS were not. The solubilities of ground products with SLS and SE were almost the same as those of respective physical mixtures. However, the apparent solubility of ground products with DCNa was 28.7 times higher than that of the physical mixture.