IDENTIFICATION OF DESVENLAFAXINE, THE MAJOR ACTIVE METABOLITE OF VENLAFAXINE, IN EXTENDED-RELEASE CAPSULES

Abstract

In this work, we describe the identification of desvenlafaxine in extended release capsules of venlafaxine (VEN) in acid degradation studies. We developed a stability indicating reverse-phase HPLC method and validated for the analysis of VEN in pharmaceutical formulation. The HPLC method was linear over the range of 0.45-1.05 mg/ml (r2=0.999). The RSD values for intra- and inter-day precision studies showed good results (RSD < 2%) and accuracy was greater than 99%. The degradation studies in acidic media for 24 h showed two additional peaks, which were further identified by ESI-MS/MS as the desvenlafaxine and the dehydration product of venlafaxine. Furthermore, desvenlafaxine is the major active metabolite of venlafaxine and has recently been approved for treatment of major depressive disorder.