Determination of indomethacin in the presence of its alkaline-induced degradation products using first-derivative spectrophotometry

ABSTRACT

A rapid and direct method for the determination of indomethacin in the presence of its alkaline induced degradation products using first- derivative spectrophotometry is presented. By measuring the absolute value of the first derivative curve at the zero contribution of the degradation products [1D 340 nm], the concentration of the intact drug can be calculated directly without interference of the degradation products. Beer's law was obeyed, for intact indomethacin, in range of 2-12 mg%. The method was proved using two sets of synthetic mixtures of the intact drug with its degradation products. The mean percentage recovery was 100.2 + ' 0.86 and 99.9 =0.74, respectively. The producer is simple, rapid and allows for accurate and precise results: