Visible spectrophotometric methods for estimation of repaglinide in tablet formulation

Two simple, economical, precise and reproducible visible spectrophotometric methods have been developed for the estimation of repaglinide in tablet formulation. The developed methods are based on the formation of chloroform extractable complex of repaglinide with zincon and methylthymol blue in acidic medium. The extracted complex with zincon shows absorbance maxima at 533.0 nm and linearity in the concentration range of 50-250 µg/ml. The extracted complex with methylthymol blue shows absorbance maxima at 427.0 nm and linearity in the concentration range of 100-500 µg/ml. Results of analysis for both the methods were validated statistically and by recovery studies.