© 2017, Springer Science+Business Media, LLC, part of Springer Nature. Two simple spectrophotometric methods were developed for determination of empagliflozin and metformin by manipulating their ratio spectra with application on a recently approved pharmaceutical combination, Synjardy® tablets. A spiking technique was used to increase the concentration of empagliflozin after extraction from the tablets to allow its simultaneous determination with metformin. Validation parameters according to ICH guidelines were acceptable over the concentration range of 2–12 μg/mL for both drugs using constant multiplication and spectrum subtraction methods. The optimized methods are suitable for QC labs.
Ayoub, B.M. Quantitative Analysis of Drugs with Highly Different Concentrations of Pharmaceutical Components Using Spectral Subtraction Techniques (2017) Journal of Applied Spectroscopy, 84 (5), pp. 884-887.