Double divisor mean centering of ratio spectra as a developed spectrophotometric method for the analysis of five-component mixture in drug analysis

In this paper a simple method was developed for the simultaneous determination of five-component mixtures, without prior separation steps. The method is based on the combination of double divisor-ratio derivative method and mean centering of ratio spectra method. The mathematical explanation of the procedure is illustrated. The linear determination ranges were 0-30, 0-20, 0-20, 0-45 and 0-100 μg ml−1 for paracetamol, methylparaben, propylparaben, chloropheniramine maleate and pseudoephedrine hydrochloride in 0.1 M HCl, respectively. The proposed method was validated by using synthetic five-component mixtures and applied to the simultaneous determination of these drugs in Decamol Flu syrup. No published spectrophotometric method has been reported for simultaneous determination of the five components of this mixture. So the results of the double divisor mean centering of ratio method (DD-MCR) were statistically compared with those of a proposed classical least squares method (CLS).