Estimation of Rizatriptan in bulk and pharmaceutical formulation

Four simple, sensitive, accurate, precise, and economical methods were developed for the quantitative estimation of Rizatriptan in bulk drug and its pharmaceutical formulation. Method-1 was a HPLC method and the chromatographic separation was carried out on column of Zorbex-eclips XDB, C18, 150 x 4.6mm, 5μ. using a mobile phase composition of acetonitrile,methanol and phosphate buffer of pH 2.5 in ratio 45:30:25 v/v pumped at flow rate of 1 ml/min. The eluent was monitored at 278 nm. The method was linear over the range of 50–150 μg/ml. The method was statistically validated for precision, accuracy, robustness and recovery. Method-2 and Method-3 are colorimetric methods based on condensation reaction involving the formation of violet colored complex between Rizatriptan and vanillin in presence of conc. Sulphuric acid which showed a linearity range 3–18 μg/ml at 558nm and formation of red colored complex between Rizatriptan and chromogenic agent 4-aminophenazone in presence of potassium ferricyanide which obeyed Beer's law in the concentration range of 20–100 μg/ml and showed absorption maxima of 531nm. Method-4 was a simple UV method developed and validated for the estimation of Rizatriptan in methanol. The linearity range for Rizatriptan was obtained as 10–50 μg/ml and its wavelength of detection was 278nm. The results of analysis for all the four methods have been validated statistically according to ICH guidelines.