Attenuated total refectance with Fourier transform infrared spectroscopy (ATR/FTIR) and different PLS algorithms for simultaneous determination of clavulanic acid and amoxicillin in powder pharmaceutical formulation

Abstract

A method for simultaneous determination of clavulanic acid (CA) and amoxicillin (AMO) was developed using Fourier transform mid infrared technique coupled with attenuated total refectance (ATR/FTIR) accessory. 27 samples were used as calibration set and 8 samples were used for prediction set. Calibration models were developed using partial least squares (PLS), interval PLS (iPLS), synergy PLS (siPLS) and backward PLS (biPLS). Multiplicative scatter correction and the mean centering were used and produced the best models. Relative standard error of prediction (RSEP) of 3.8% for CA and 5.1% for AMO were obtained using biPLS algorithm for ATR/FTIR data. Results obtained by the proposed methodology were compared with those using high performance liquid chromatography (HPLC) and no signifcant differences were obtained. The proposed method using ATR/FTIR combined to multivariate analysis methods was suitable for the simultaneous determination of CA and AMO in commercial pharmaceutical products. © 2011 Sociedade Brasileira de Química.