Spectrophotometric Determination of Aspirin in Pure Form and Pharmaceutical Formulations using Oxidation–reduction reaction

Abstract

A simple, sensitive and accurate spectrophotometric method of determinationof aspirin in pure form and pharmaceutical formulation.The method is based on the formation of Prussian blue (PB) complex. Thereaction between the acidic hydrolysis product of the aspirin with the mixture ofFeCl3 and potassium hexacyanoferrate (ΙΙΙ) was evaluated for thespectrophotometric determination of the aspirin. The maximum absorbance ofthe colored complex occurred at λ=765nm. Reaction conditions have beenoptimized to obtain PB complex of high sensitivity and longer stability. Underoptimum conditions the absorbance of the PB complex where found to increaselinearly with increase in concentration of the aspirin, which corroborated withcorrelation coefficient value. The concentration ranges are 0.5-7μg mL-1 withdetection limit 0,2267μg mL-1 and relative standard deviation 0,025%. Theproposed method was successfully applied to determine of the selected aspirin inpure form and pharmaceutical formulations with good precision and accuracycompared to standard method as revealed by t- and F- values and the resultsobtained agree well with the labeled contents.Key word: Aspirin, spectrophotometric, oxidation–reduction reaction.