Development and Validation of Spectrophotometric Method for Determination of Riluzole in its Dosage Form Using Phloroglucinol as coupling Agent

The goal of the present study was to create and validate a newly developed, quick, precise, and easy-to-use spectrophotometric technique for identifying substances with amino group in pure and in pharmaceutical formulations, particularly riluzole. Two steps are involved in the suggested procedure: first, diazotization of riluzole's primary amine with sodium nitrite in an acidic medium to form riluzole diazonium salt; second, reacting the diazonium salt with reagent in a basic medium to produce a stable purple-red water-insoluble dye with maximum absorption at 530 nm. As a result, the resulting azo dye satisfies Lambert's law within a concentration range of 20 – 50 mg/L. The method was tested for linearity, precision, accuracy, and limits of quantification and detection. It was also optimized for several production variables. The results confirmed the statistical validity of the methodology with a molar absorptivity of 6.8443 ×10+3 L.mol-1. cm-1 and a Sandell's sensitivity of 0.0227 mg. L-1/0.001 abs. unit. .In overall, the findings indicate which this approach succeeds well for routinely measuring riluzole in quality control procedures involving both pure and tablet formulations.