Fabrication, Evaluation and Comparison of Metformin Tablets by Using Different Binders Effect on The Dissolution Rate

Abstract

The objective of the present study is to evaluate the effect of commonly used binders on the dissolution rate of metformin tablets. Tablets each containing 100 mg of Metformin hydrochloride were formulated employing commonly used binders namely acacia, starch paste, polyvinyl pyrollidine (PVP K30), sucrose, methyl cellulose LV and hydroxy propyl methyl cellulose (HPMC E5LV). For comparison purpose all the binders were used at the same strength, 2% w/v in the formula. The tablets were prepared by wet granulation method. All the tablets prepared were evaluated for drug content, hardness, friability, disintegration time and dissolution rate as per official methods. All the metformin tablets prepared using various binders disintegrated with in 2 min. Tablets formulated using acacia and sucrose as binders disintegrated very rapidly in30 and 40sec respectively when compared to others. Many variations were observed in the dissolution characteristics of the metformin hydrochloride tablets prepared and commercial brands tested. The binder used has significantly influenced the dissolution rate of metformin tablets prepared. Among all, tablets formulated using acacia and commercial product C3 gave rapid and higher dissolution of metformin hydrochloride. The order of increasing dissolution rate (K1) observed with various binders was acacia = C3 > starch paste > sucrose> methyl cellulose > PVP K30> C1 > C2 > HPMC. Tablets formulated using HPMC as binder and commercial brands C1and C2 gave relatively low dissolution of metformin hydrochloride .All the metformin tablets prepared and the three commercial brands tested fulfilled the dissolution rate specification of NLT 70% in 45min prescribed for metformin tablets in IP 2010. Hence acacia, starch paste, poly vinyl pyrollidine (PVP K30), sucrose and methyl cellulose LV are recommended as binders for the preparation of metformin hydrochloride tablets.