Sustained release of venlafaxine from venlafaxine–montmorillonite–polyvinylpyrrolidone composites

Due to shorter half life of venlafaxine, it is a prime requirement to develop a formulation which could extend the release of venlafaxine in the human body and also eliminate daily multiple dosage of venlafaxine. Montmorillonite (MMT) was used as sustained release carrier for venlafaxine by preparing venlafaxine–MMT by ion exchange. Venlafaxine–MMT was coated with polyvinylpyrrolidone to delay the release of venlafaxine. In vitro releases of venlafaxine from the various formulations were carried out in simulated gastric and intestinal fluids in controlled environment. 50% of venlafaxine was released by intestinal fluid within 5 h, > 95% within 48 h. Venlafaxine–MMT coated with PVP further decreased the release of venlafaxine.