Md. Sarfaraz, P. Keerthi Chandra Reddy, Udupi R.H, H. Doddayya
The present investigation concerns the development of bilayer floating tablets of Tramadol hydrochloride (TH) for prolongation of gastric residence time. TH is a synthetic opioid analgesic used to treat moderate to severe pain. An attempt was made to prepare bilayered floating tablets of TH by wet granulation method using release retarding polymers like hydroxypropyl methyl cellulose grades (HPMC K4M, K15M, K100M), PEO, Sodium alginate and sodium bicarbonate as gas generating agent, with a view to deliver the drug at sustained or controlled manner in gastrointestinal tract and consequently in to systemic circulation. Five formulations were prepared and evaluated for compatibility study, buoyancy lag time, total floating time, swelling study, in-vitro disintegration and in-vitro dissolution studies. Formulations were found uniform with respect to thickness (5.04 to 5.07 mm) and hardness (6.3 to 6.6 kg/cm2). The friability (0.29 to 0.37%), weight variation (1.44 to 1.71%) and Drug content (98.73 to 99.23%) of different batch of tablets were found within prescribed limits. Formulation F3 selected as best formulation, shown buoyancy lag time of 39 sec, total floating time of 36 hrs and drug release of 95.90% in a period of 24 hrs. Tablets followed diffusion controlled first order kinetics and non- fickian transport of the drug. FTIR study revealed the absence of any chemical interaction between drug and polymers used.