Development of infrared methodologies applied to determination of the metformin hidrochloride in pharmaceutical formulations

Abstract

In this work 20 metformin hydrochloride commercial pill samples and 14 synthetic samples were used and their spectra acquired in the 4000 – 650 cm-1 range by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). Multivariate calibration models were built and compared using all spectral region (global model PLS) and optimized models applying FTIR spectral sub-regions (iPLS and siPLS models). The best results were the ones obtained by using the siPLS algorithm, dividing the spectrum into 40 intervals and combining 3 intervals (37, 39 and 40) with 4 latent variables, which also presented an RMSEP value lower than the one obtained by using the global model and the iPLS algorithm. Finally, the application of selection techniques for infrared spectral regions (iPLS and siPLS) has been efficient to develop simpler, faster and non-destructive methodologies to analyze pharmaceutical pill formulations containing metformin, highlighting the potentialities of these techniques to control and inspect industrialized medicines.