Preparation of Venlafaxine Hydrochloride Sustained Release Pellets and Its Release Test in Vitro

OBJECTIVE To characterize venlafaxine's release behavior in vitro following the preparation of venlafaxine hydrochloride sustained-release pellets.METHODS At first,the drug substance was microencapsulated into an EC solution to prepare fast-release pellets by a centrifugal granulator;then,the fast-release pellets was used as the core and microencapsulated into aqueous dispersed coating materials made of Eudragit NE 30D to prepare sustained-release pellets;next,the fast-release pelltes and sustained-release pellets were mixed with a ratio of 1:2 to make the final sustained-release pellets.The effects of coating thicknesses on the sustained-release parameters were analyzed.RESULTS The optimal sustained release behavior in vitro of the sustained-release pellets mixed from fast-release pellets and sustained-release pellets with a ratio of 1:2 was selected when the amount of coating materials was 20% of total weight.CONCLUSION The venlafaxine hydrochloride sustained-release pellets provided a rather good sustained-release efficiency.