Spectrophotometric methods for the estimation of nitazoxanide in pharmaceutical formulations

Abstract

Three simple and sensitive spectrophotometric methods (I, II, and III) in the visible region have been developed for the quantitative estimation of nitazoxanide in bulk drug and pharmaceutical formulations. These methods are based on the reaction of reduced nitazoxanide with p-dimethylaminobenzaldehyde, p-dimethylaminocinnamaldehyde and vanillin in acidic conditions to form pink, orange red, and orange yellow coloured chromogens with absorption maxima at 559 nm, 534.5 nm, and 475 nm respectively. The reduction of nitazoxanide was carried out with zinc granules and 5 N hydrochloric acid at room temperature in methanol. Beer's law is obeyed in the concentration range of 5-25 mg/ml, 5-25 mg/ml, and 10-50 mg/ml respectively. The results of analysis have been validated statistically and by recovery studies. The methods were found to be accurate, precise, rapid, and economic. The results are comparable with those obtained with visible spectrophotometric method in methanol at 402 nm.