Objective: To investigate in vitro release characteristics of Shuxiong pulsatile controlledrelease dropping pills( SPCDP). Method: Determination of dissolution was taken by small glass method,effects of dissolution medium and stirring rate on in vitro release behavior were investigated,then release mechanism and characteristics of pulsatile controlled-release dropping pills were explained. Result: Release behavior of SPCDP was influenced most greatly by pH value of dissolution medium. Release behavior of pu...