Color based spectrophotometric determination of vericiguat using diazo coupling reaction; assisted computational calculations

Abstract

A novel spectrophotometric method aided by computational techniques has been developed to determine vericiguat, a soluble guanylate cyclase stimulator used for reducing the risk of heart failure and cardiovascular mortality. Using density functional theory calculations, 8-hydroxyquinoline was identified as the best coupling agent for the spectrophotometric determination of vericiguat. The method involves the creation of a red-colored chromogen by combining vericiguat with sodium nitrite to form a diazonium ion, which then reacts with 8-hydroxyquinoline. The resulting complex exhibits distinct absorption peaks at 515 nm. Various factors influencing the diazotization process were investigated, and the concentration range of 1–12 μg/mL vericiguat was found to adhere to Beer's law. Job's plot analysis revealed a 1:1 stoichiometric ratio between vericiguat and 8-hydroxyquinoline. This reaction formed the basis for determining vericiguat spectrophotometrically, both in its pure form and in pharmaceutical formulations. Additionally, an analytical greenness metric was employed to evaluate the environmental friendliness of the proposed procedure. The results demonstrated that the method aligns with established values of green analytical chemistry metrics.