Design and Characterization of Effervescent Gastro Retentive Floating Tablets by Using Venlafaxine Hcl as a Model Drug

In the present research work the gastro retentive floating matrix formulation of Venlaflaxine hydrochloride by using various hydrophillic polymers. Initially analytical method development was done for the drug molecule. Absorption maxima was determined based on that calibration curve was developed by using different concentrations. Gas generating agent sodium bicarbonate concentration was optimized. Then the formulation was developed by using different concentrations of polymers of various grades of HPMC and Guar gum. The formulation blend was subjected to various preformualation studies, flow properties and all the formulations were found to be good indicating that the powder blend has good flow properties. Among all the formulations the formulations prepared by using Guar gum were in the concentration of 120mg (F4) showed maximum drug release 99.76% in 12 hours with good floating lag time and duration of floating.The formulations prepared with HPMC K 15 M retarded the drug release up to 12 hours in the concentration of 120 mg (F8).The formulations prepared with HPMC K100M were also retarded the drug release for more than 12 hours. Hence they were not considered. The optimized formulation dissolution data was subjected to release kinetics; from the release kinetics data it was evident that the formulation followed peppas mechanism of drug release.