Formulation and Evaluation of Controlled Release Floating Tablets of Venlafaxine HCl Using Almond Gum

ABOUT AUTHOR 
Y. Sravani*¹, S. Md. Shahidullah¹, Ch. Sri Vidya¹, C. Swomya^2
1Department of Pharmaceutics, Dr. Samuel George Institute of Pharmaceutical Sciences,
Markapur, Prakasam, A. P. India.
²Department of Pharmaceutics, RIPER, Anantapur, A. P. India

Abstract
The purpose of this research was to prepare a floating drug delivery system of an anti depressant agent, Venlafaxine which is a unique antidepressant, and is referred to as a serotonin-norepinerphrine-dopamine reuptake inhibitor. Eight (F1-F8) various formulations of venlafaxine HCl and Almond gum floating tablets each containing 75 mg of drug were prepared by wet granulation method. Preformulation studies were done by FTIR and DSC and found to be no interaction between the API and excipients. Accurately weighed active ingredient and other excipients were passed through ASTM (American Society for Testing and Materials) mesh no. #80 and mixed thoroughly. The powder blend was granulated using the mixture of PVP and IPA mixture as a granulating fluid. After achieving required cohesiveness the mass was passed through sieve no.#30 to collect wet granules. The granules obtained were dried at 60^oc for 2 hrs and kept them in a desiccator for 24 hrs at room temperature. The granules were lubricated with talc (2% w/w) and magnesium stearate (2% w/w) and compressed into tablets using 9 mm round, flat and plain punches on pilot scale tablet compressing machine (MODEL MINI PRESS II MT). Lactose USP was used as a filler in the formulations. The tablets were evaluated for thickness, weight variation, hardness, friability, drug content; in vitro buoyancy test, in vitro drug release. Formulation F5 can be considered as an optimized formulation for gastro retentive floating tablet of venlafaxine HCl. The results of in vitro release studies showed that optimized formulation F5 could sustain drug release (99.70 %) for 12 hours and remain buoyant for more than 12 hours. Natural polymer shows better sustained release properties than synthetic polymer. The developed floating tablets of Venlafaxine HCL may be used in clinic for prolonged drug release for at least 12h in sustained release gastro retentive floating drug delivery system.
Key words: venlafaxine HCl, Almond gum, anti-depressant agent, gastro retentive floating tablet.