To prepare a solid dispersion of cisapride with hydroxypropylmethyl cellulose(HPMC E5 LV) as carrier for the purpose of accelerating the in vitro drug release by means ofimproving the solubility of the model drug. Methods Alcohol and simulated gastric fluid (SGF) wereused to dissolve cisapride and HPMC in order to make the model drug dispersed homogeneously in thecarrier. The HPMC-cisapride solid dispersion was then obtained by conventional solvent evaporationmethod. Powder X-ray diffraction (XRD) was used to measure the diffraction peaks of pure carrier,pure cisapride, physical mixture of HPMC with cisapride (4:1), and HPMC-cisapride solid dispersion(4:1) to confirm the crystal existence. The solubility of pure drug and HPMC-cisapride soliddispersion was measured with water, SGF and simulated intestinal fluid (SIF) . The in vitro drugreleases of the sustained release tablet prepared with pure cisapride or HPMC-cisapride soliddispersion were investigated with water and SGF as media, respectively. Results No diffraction peakswere found by X-ray diffraction in the HPMC-cisapride solid dispersion (4:1), indicating that thedrug existed in an amorphous form at that drug-carrier ratio. Compared with the pure drug, thesolubilities of HPMC-cisapride solid dispersion are increased by 239.4% in SGF, 132.6% in water, and117.9% in SIF. According to the in vitro drug release, the sustained release tablet prepared withHPMC-cisapride solid dispersion had a faster drug release than did that prepared with pure drug. Thein vitro drug release profiles were found to comply with Higuchi's rule. Conclusion The in vitrodrug release of the sustained release tablet made by HPMC-cisapride solid dispersion is improvedowing to the increased drug solubility.
