ABSTRACT
OBJECTIVE: To prepare mifepristone gastric retentive multi-unit pellet system (MUPs), and study its release behaviors in vitro. METHODS: A sustained release layer and mucous adhesive layer were coated onto extrusion spherized mifepristone pellets. The gastric retentive sustained release pellets were mixed with granules which were wet granulated from micronized mifepristone and compressed into MUPs tablets. Investigation and evaluation of the in vitro release of mifepristone MUPs tablets were carried out from different aspects. RESULTS: The turning point of pH value for the solubility of mifepristone was 3.0.Micronized mifepristone showed higher dissolving rate and apparent solubility. The gastric retentive mifepristone MUPs tablets had faster release than marketed mifepristone tablets. The in vitro adhesive experiment with pig stomach showed that mucous adhesive mifepristone pellets could be entrapped into the gastric mucous and retained for a long time. The accelerated stability study showed that mifepristone MUPs tablets were as stable as marketed mifepristone tablets. CONCLUSION: Novel mifepristone gastric retentive MUPs tablets are successfully prepared. The release characteristics in vitro indicate that the product may have higher bioavailability than marketed mifepristone tablets with significantly lower variability.