Chloramine-T-induced oxidation of Rizatriptan Benzoate: An integral chemical and spectroscopic study of products, mechanisms and kinetics

Abstract

Oxidation is a prominent degradation route of biological molecules that produces a wide variety of degradation products through complex mechanisms and hence qualifies to be a vital pharmaceutical process. This article presents the kinetic and spectral study of the oxidation of an antimigraine drug rizatriptan benzoate (RTB) in an acid medium with the aid of a mild biocidal oxidant N-chloro-p-toluenesulfonamide, referred to as chloramine-T (CAT). The kinetic experimental studies reported here, such as fractional order dependency on RTB, pseudo-first-order dependency on CAT, negative fractional order dependency on the acid medium, independent of the rate on the ionic concentration and increasing rate with increasing dielectric constant, have led to the evaluation of stoichiometry, thermodynamic properties, and derivation of a rate equation. Effective interpretation of UV–Vis, IR, 1H and 13C NMR investigation was performed to identify and confirm the identity of the oxidation products and discuss the involved plausible mechanism. This study provides an extended insight into the products of oxidation formed during the metabolism of RTB.

Keywords

• rizatriptan benzoate
• oxidation product
• kinetics
• chloramine t
• spectrophotometric analysis
• 1h and 13c nuclear magnetic resonance
• indole
• imide