Abstract

Estimation and validation of metformin by colorimetry method

Author(s): Vijay Vikram Singh, Amit Kumar, G.T.Kulkarni, R. Hemalatha

A simple highly sensitive spectrophotometric method was developed for the quantification of metformin hydrochloride. The method involves the reaction of the target compound with ninhydrin reagent at specific pH 5.6 to produce a wine red color chromogen. The derivative chromogen exhibits absorption maxima at 567nm. At the specific pH of the reaction where no degradation may occur with that medium the proposed method can be utilized as a stability indicating assay. The different experimental parameters affecting the derivatization reaction were carefully studied and incorporated into the procedure. Under the described conditions the proposed method is linear over the concentration range of 10-70mcg/ml and the coefficient of determinationwere >0.999(n=6) with a relative standard deviation of 0.083% (n=6). The average recovery of the target compound is 99.47% with a limit of quantification (LOQ) of 2.637mcg/ml and the limit of detection (LOD) 0.870mcg/ml. The mechanism of the derivatization reaction is proposed and advantages of the proposed method are discussed.