Studies on Preparation of Bergenin Inclusion Compound Osmotic Pump Tablets

OBJECTIVE To improve the release character in vitro of slightly soluble bergenin by using β-cyclodextrin (β-CD) inclusion technology. And investigate the effect of the formulation of core tablets and coating on bergenin inclusion compound osmotic pump tablets release in vitro and optimize the formulation. METHODS The bergenin-β-CD inclusion complex was prepared by saturation water-solution. And the phase solubility and dissolution test was also determined. The release in vitro was studied through cumulative release measuring. And the optimal formulation of bergenin inclusion compound osmotic pump tablets was selected via the single-factor method and orthogonal design. RESULTS The molecular weight of polyethylene oxide (PEO), the amount of PEO and mannitol agents were all found to have great effect on release in vitro of bergenin inclusion compound osmotic pump tablets. The tablets with optimized formulation could achieve the desired zero-order release profile in 12 hours and the cumulative release over 90%. CONCLUSION The bergenin inclusion compound monolithic osmotic pump tablets could deliver drug constantly for 12 h based on the intermediat of bergenin-β-CD inclusion complex.