Spectrophotometric Methods for the Determination of Cefprozil in Bulk and Dosage Form

Two simple spectrophotometric methods were developed for the determination of cefprozil in pure bulk and in tablets forms. The first is a colorimetric method based on the coupling of cefprozil, after being hydrolyzed by sodium hydroxide (0.1N), with ascorbic acid as a chromogen (method A). It has been established that cefprozil reacts with ascorbic acid to form a 1:1 water soluble colored product with maximum absorbance (λmax) at 408 nm and molar absorptivity of 7.2 × 10(3)L mol(-1) cm(-1). The second method (Method B) utilizes a direct reaction between cefprozil and sodium hydroxide (1N). A colored product with λmax at 486 nm and molar absorptivity of 7.4 × 10(3) L mol(-1) cm(-1) is formed after heating cefprozil with sodium hydroxide (1N). The absorbance-concentration plot was rectilinear over the range 5-25 µg/ml in both methods with correlation coefficient values not less than 0.999. The detection limits (L.O.D.) were 0.96 µg/ml and 0.93 µg/ml for method A and method B respectively. The methods were validated using the USP liquid chromatography method for cefprozil assay. The results obtained by the USP liquid chromatography method for the tablets dosage form were statistically compared with those of the developed methods and evaluated at 95% confidence limits.