RESUMO
OBJECTIVE: To prepare Shuxiong pulsatile controlled-release dropping pill and study the influencing factors in vitro. METHODS: Dropping pills with suitable size (10 - 15 mg) were coated with swelling layer containing croscarmellose sodium and controlled-release layer containing ethylcellulos aqueous dispersion respectively to prepare Shuxiong pulsatile controlled-release dropping pill. The effects of the materials of swelling layer, the weight of swelling layer and controlled-release layer on the release of drugs were investigated to optimize the process technology and validate formula. RESULTS: The release behavior was influenced strikingly by the types and weight of coating layer. The optimal formula was as follows: Shuxiong pulsatile controlled-release dropping pills were prepared using croscarmellose sodium as inner layer with 15% (weight) coating level and ethylcellulose aqueous dispersion (Surelease) as outer controlled-release layer with 7% (weight) coating level. The lag time of prepared pulsatile controlled-release dropping pills was about 4 h and accumulative release rate reached 80% within 4 h. CONCLUSION: The drug release of Shuxiong pulsatile controlled-release dropping pill is shown in pulsatile way in vitro.
