Design and evaluation of lafutidine floating tablets for controlled release by using semi-synthetic and natural polymer

Abstract

Purpose: Lafutidine is H2-receptor antagonist. The prepared tablets of various formulations were evaluated for a total floating time, buoyancy lag time, and percentage drug released. Guar gum is an efficient matrix forming agent in floating tablets by generating gas. Drug release from the prepared tablets was slowed over more 12 h and depended on the composition of guar gum and sodium bicarbonate. Lafutidine release was diffusion controlled and follows zero order kinetics. In case of F3 formulation non-fickian diffusion was the drug release mechanism from the prepared lafutidine floating tablets.

Methods: Floating tablets containing 10 mg of lafutidine could be prepared by wet-granulation technique employing guar gum of different grades as floating  polymer and release retardant, methocel K100LVCR, methocel K15M as  floating enhancers and sodium bicarbonate as a gas generating agent.

Results: The influence of various process parameters on physic-chemical properties and drug release potential have been studied. Different formulation ratios of blend affect the physical appearance of the tablets and micromeritic properties were observed. The measured tapped density was 0.501 to 0.643(g/cm³), bulk density 0.421 to 0.540 (g/cm³), Carr’s index(I) 10.88 to 23.04%, thickness 4.33 to 4.38(mm), hardness 4.26 to 5.06 (Kg/cm²), friability 0.24 to 0.46(%) were well within the limits, which indicates good flow potential of the prepared tablets. Angle of repose (θ) values for the granules was in the range 24.19 to 26.95⁰ indicating good flow potential for the tablets.

Conclusion: Although the tablets with guar gum were able to float for more than 12 h. Resultant tablets blend did not have any incompatibilities showed in FT-IR studies.

Keywords: Floating drug delivery system, in vitro, lafutidine and controlled release.