To improve its solubility and dissolution,solid dispersions of silybin in PVP K30 were prepared by the conventional solvent evaporation method and characterized by equilibrium solubility and dissolution studies,differential scanning calorimetry （DSC） and Fourier transform infrared spectroscopy（FTIR）.Silybin solid dispersions showed increased solubility and rates of dissolution compared with pure drug and corresponding physical mixtures of silybin and PVP K30.Thermograms of various solid dispersions did not show the melting peak of pure silybin,indicating that silybin was in amorphous form inside the polymer carrier.FTIR studies demonstrated the presence of interactions between hydroxyl groups of silybin and carbonyl groups of PVP K30 in solid dispersions.Solid dispersion techniques can be used to formulate water insoluble drugs to improve their dissolution in vitro and absorption in vivo.
