Two simple, economic and highly sensitive uv-spectrophotometric methods have been described for the determination of rizatriptan benzoate (RTB) in bulk drug and in tablets. The proposed methods are based on the measurement of the absorbance of RTB either in 0.1 M HCl (method A) or in 0.1 M NaOH (method B) at 226 nm. Linearity was found to be in the ranges, 0.4-10.0 and 0.25-10.0 µg/ml RTB, for method A and method B, respectively with apparent molar absorptivity values of 5.01 x 104 and 6.09 x 104 l/mol/cm. The sandell sensitivity values, limits of detection (LOD) and quantification (LOQ) values have also been reported for both the methods. The proposed methods were successfully applied to the determination of RTB in tablets with good accuracy and precision and without detectable interference from common excipients. The validity and reliability of the proposed methods were further assessed by performing recovery studies via standard addition method. The degradation behaviour of RTB was investigated by subjecting it to different ICH prescribed stress studies like dry heat treatment, UV-degradation, acid hydrolysis, alkali hydrolysis and wet oxidation. The drug undergoes significant degradation under oxidation condition only. No degradation was observed under other stress conditions.
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