Preparation of Urapidil Osmotic Pump Tablets / 中国药房

OBJECTIVE:To prepare urapidil osmotic pump tablet(OPT) characterized by 24 h constant drug release in vitro.METHODS:OPT of urapidil was prepared using NaCl and low or high moleculan weight PEO(Mr 4?106、2?105) as core,CA and PEG-400 as the coating material.Similarity factor was used to evaluate formulation of osmotic pump tablets.The drug release mechanism was investigated as well.RESULTS:The optimal core formulation consisted of urapidil 60 mg,NaCl 190 mg,PEO(Mr 4?106) 90 mg,PEO(Mr 2?105) 90 mg.The drug was released from OPT at controlled rate 24 h.CONCLUSION:The preparation of osmotic pump tablets was simple and characterized by zero-order release.