Simultaneous determination of paracetamol and codeine phosphate in pharmaceuticals using molecular absorption spectroscopy and classical least squares method

In this article, a combined method of molecular absorption spectroscopy and classical least squares is used to simultaneously determine paracetamol (PAR) codeine phosphate (COP) in pharmaceutical samples without the need for prior separation or extraction steps. The spectra standard solutions were measured wavelength range 210 290 nm with step size 0.5 nm. concentrations PAR COP sample calculated using self-made program written Microsoft Excel 2016 Visual Basic Applications (VBA). reliability was verified through accuracy reproducibility measurements when analyzing Effer-Paralmax® Codeine tablets, comparing average values their HPLC method.