Stability-indicating Method for the Estimation of Riluzole in Tablets

A stability-indicating reverse-phase high-pressure liquid chromatography method with photodiode array detector was developed and validated for estimation of riluzole in the bulk and tablet dosage forms. Riluzole was subjected to stress conditions (light, heat, humidity, acid/base hydrolysis and oxidation) and the stressed samples were analyzed by developed method. Degradation was observed in acidic, basic, oxidative and thermal conditions. The degradation products were well resolved from riluzole peak. An inertsil-ods column (250×4.6 mm, 5 μ) with a mobile phase comprising 0.02% v/v formic acid:acetonitrile(35:65 v/v) at a flow rate of 1.0 ml/min was used and eluents were monitored at 260 nm. The retention time of riluzole was 5.7 min. Complete validation for the method was carried out according to Internation Conference on Harmonization guidelines. Linearity was achieved in the range 10-50 μg/ml with a correlation coefficient (r) 0.9998. The percent assay was 100.92 and mean percentage recovery was found to be 101.10.