Development and Evaluation of Furosemide Buoyant Tablet Dosage Form

Abstract

To get an optimum floating dosage form of furosemide, several formulation variables like different types, different percentages of HPMC, different percentages of sodium bicarbonate, and different percentages of magnesium stearate, were evaluated using the three level factorial design. Dosage form buoyancy was shown to depend on the viscosity grade of the polymer used. Moreover, onset of floating ofthe developed dosage forms was shown to be under the influence of percentage of polymer added, content of sodium bicarbonate included and the swelling / erosion ability of the polymer used. Swelling and erosion were also investigated to be buoyancy duration determining factor. USP 24 apparatus 2 was used to evaluate the in vitro dissolution from the developed floating tablets. Drug release from the dosage form was found to vary with the content and viscosity grade of the polymer used. Moreover, sodium bicarbonate was significantly enhancing furosemide release from the dosage form (p< 0.05). Drug release from tablets of the invention was shown to be controlled by both diffusion and polymer chain relaxation (anomalous). Tablet hardness showed no significant influence on the drug release (p> 0.05), but it was a powerful tool for dosage form buoyancy. In-vivo evaluation of the developed dosage form in dogs resulted in a significant increase in furosemide systemic availability (1.3 times) compared to conventional tablet. Based on the in vitro and in-vivo investigation findings, buoyant tablets might be considered as a feasible approach in delivering furosemide; however, such feasibility needs to be verified among large population of human subjects.