Spectrophotometric Estimation of Sulfacetamide Sodium Using N,N-Diethyl-p-phenylenediamine Reagent

A simple, accurate and sensitive spectrophotometric method was described for the determination of sulfacetamide sodium in an aqueous solution. The method is based on the oxidative coupling reaction of N,N-diethyl-p-phenelenediamine with sulfacetamide sodium in the presence of potassium dichromate as an oxidizing agent in an acidic medium to form a violet-colored product, which has a maximum absorbance at 546 nm. Beer׳s law is obeyed in the concentration range of 1.25-75 µg.ml -1 of sulfacetamide sodium, with a molar absorptivity of 0.76×10 4 L.mol -1 .cm -1 and sandell , s sensitivity value of 0.03344 μg.cm -2 .The relative error values are in between-2.01 and -0.14 while the relative standard deviation values are in between 0.34 and 1.55. The proposed method was applied successfully to assay sulfacetamide sodium in its pharmaceutical preparations as eye drops and ointment.