[The dissolution rate and physical dispersion state of preparations of biphenyl dimethyl dicarboxylate (DDB)]

DDB is poorly soluble in water. The solid dispersions of DDB with easily soluble carriers such as polyethylene glycol 6000 (PEG 6000), polyvinyl pyrrolidone (PVP) and urea were prepared by melting and solvent methods. The two DDB-PEG 6000 systems are thermodynamically stable interstitial solid solutions. The DDB-PVP system is an amorphous precipitate and the DDB-urea system is a simple eutectic physical mixture judged by X-ray diffraction and thermal analysis methods. The dissolution rate of DDB-PEG 6000 pilule and two kinds of DDB tablets were determined. The dissolution rate of DDB-PEG 6000 pilule was found to be faster. The physical dispersion state is an important factor in relation to the dissolution rate of DDB preparations.