Formulation Development and Evaluation of Floating Tablets of Venlafaxine Hydrochloride

Abstract

The aim of the present study was to formulate and evaluate gastroretentive floating tablets of an antidepressant drug, Venlafaxine HCl. The matrix tablets of Venlafaxine hydrochloride were prepared by employing low viscosity grade hydrophilic polymer HPMC E15LV in combination with any one of the high viscosity grades of HPMC (K4M, K15M, and K100M) as swelling polymers. Sodium bicarbonate was employed as gas generating agent. The tablets were formulated using direct compression technique and evaluated in terms of hardness, friability, weight variation, drug content, water uptake, in-vitro floating behavior, and in-vitro drug release study. Formulation L3 containing HPMC E15 LV and HPMC K15M in 1:3 ratio was considered as an optimized formulation. The optimized formulation exhibited short floating lag time of <1 min and remained buoyant on the surface for 12 h. It exhibited satisfactory sustained release and stability. It can be concluded that floating delivery system of Venlafaxine HCl can be successfully formulated as an approach to increase gastric residence time and thereby improving its absorption and bioavailability.

Keywords: Venlafaxine HCl, hydroxy propyl methyl cellulose, gastroretentive floating tablets, in-vitro drug release, non-fickian diffusion