Validated hplc-uv method for determination of venlafaxine and its metabolite - o-desmethylvenlafaxine in human plasma

This paper describes a simple, rapid, and cost-effective HPLC-UV method for the determination of venlafaxine and its active metabolite O-desmethylvenlafaxine in human plasma. Sample preparation is based on a liquid-liquid extraction procedure with a short extraction time. Prazosine hydrochloride was used as the internal standard. The HPLC separation was performed on a Supelcosil LC-CN column, using a mobile phase consisting acetonitrile: 25 mM phosphate buffer at pH 3.5 (15: 85 v/v). The calibration curve is linear in the concentrations range of 25-1000 ng/mL, which is suitable for pharmacokinetic studies of venlafaxine hydrochloride following dosing from 37.5 mg to 375.0 mg per day. The method was fully validated according to international guidelines.