Metformin HCL is an oral anti-diabetic drug and it comes under biguanide class. Plasma half–life of Metformin after intravenous administration, about 1.5 to4 h. Absorption of the metformin HCl is limited to upper part of the GI tract and therefore its bioavailability from both immediate and sustained release marketed dosage forms is 50- 60%. So metformin is suitable for gastro retentive drug delivery system, which may improve bioavailability. Floating matrix tablets containing of Metformin HCL were prepared using wet granulation method using HPMC K100M, Eudragit RL 100 as polymer and Sodium Bicarbonate as gas generating agent. The prepared formulations wereevaluated for hardness, weight variation, friability and drug content,floating time and in vitro drug releasecharacteristics.Comparison between optimized and marketed formulation by similarity factor (ƒ2) divulged similarity in release profile between both. Release kinetic study showed that all batches followed Fickian diffusion.
