Abstract

Visible Spectrophotometric Methods For The Determination Of Rizatriptan In Pure Form And In Pharmaceutical Formulations

Author(s): Dannana Gowri Sankar, Marothu Vamsi Krishna

Three simple spectrophotometric methods (A, B and C) are described for the determination of rizatriptan (RZT) in pure form and in pharmaceutical formulations. Method A is based on the oxidative coupling reaction between RZT with 2, 6- dichloroquinone - 4 -chlorimide (DCQC) and the color developed was measured at 610 nm. Method B is based on the replacement of sulfonate group of 1, 2 - napthoquinone - 4- sulphonic acid (NQS) by an imino group of indole moiety of RZT producing a colored product which absorbs maximally at 480 nm. Method C is based on the oxidative coupling reaction between RZT and brucine in presence of sodium metaperiodate and the color developed was measured at 530 nm. The optimum experimental parameters for the color production are selected. Beer’s law is valid with in a concentration range of 5.0 - 25.0 μg/ml for method A, 15-75 μg/ml for method B and 8 -40 μg/ml for method C. The results obtained are reproducible and are statistically validated and found to be suitable for the assay of RZT in pharmaceutical formulations.