Effect of Superdisintegrants on Physical Attribute and Release Profile of Metformin HCl Immediate Release Tablets

An immediate action of Metformin HCl is essential for emergency treatment of diabetes. With an objective of finding the best suitable disintegrant for immediate release tablet of Metformin HCl, different formulations were prepared by incorporating varying ratios of three widely used superdisintegrants both by intra and extra granularly. Wet granulation method was adopted to formulate the tablets by using Maize Starch as diluent; Povidone k-30 as binder; Sodium Starch Glycolate/Kollidon CL/Crosscarmellose Sodium as superdisintegrants in different concentration (2-3.5%), Aerosil-200 as flow promoter and Magnesium Stearate as lubricant. To evaluate the rheological properties of powdered blend, some pre-compression characteristics including bulk and tapped densities, compressibility index, Hausner’s ratio, angle of repose were studied. The compressed tablets were evaluated for hardness, thickness, diameter, friability, drug content, weight variation, in vitro dispersion time, in vitro disintegration time, in vitro wetting time and finally for in vitro dissolution studies. It was found that wetting time, dispersion time and the disintegration time of the tablets were governed by the type and quantity of the superdisintegrants. In vitro drug release data obtained at phosphate buffer at pH 6.8 also found reliant on successful incorporation of right disintegrating agent. Higher the disintegrant ratio in the formulation, lower the disintegration time and hence, higher percentage of drug release was obtained. Based upon results of different studies, Sodium Starch Glycolate has been proven successful in rapid disintegration of tablets and enhancing dissolution behavior.