Multivariate analysis of paracetamol, propiphenazone, caffeine and thiamine in quaternary mixtures by PCR, PLS and ANN calibrations applied on wavelet transform data

The quantitative resolution of a quaternary pharmaceutical mixture consisting of paracetamol,propiphenazone, caffeine and thiamine was performed by the simultaneous use of fractional wavelettransform (FWT) with principal component regression (PCR), partial least squares (PLS) and artificialneural networks (ANN) methods. A calibration set consisting of 22 mixture solutions was prepared bymeans of an orthogonal experimental design and their absorption spectra were recorded in the spectralrange of 210.0–312.3nm and then transferred into the fractional wavelet domain and processed by FWT.The chemometric calibrations FWT–PCR, FWT–PLS and FWT–ANN were computed by using the relationshipbetween the coefficients provided by FWT method and the concentration data from calibration set.An external validation was carried out by applying the developed methods to the analysis of syntheticmixtures of the related compounds, obtaining successful results. The models were finally used to assaythe studied drugs in the commercial pharmaceutical formulations.