Development of Two Green and High-Throughput Microwell Spectrometric Platforms for Determination of Reboxetine, the First FDA-Approved Selective Noradrenaline Reuptake Inhibitor Antidepressant Drug.

Background: Reboxetine (RBX) is the first FDA-approved antidepressant drug of the selective noradrenaline reuptake inhibitors class. There is a serious need for a convenient analytical tool for the quantitation of RBX in its dosage form.

Objective: This study aims toward the development and validation of two green and high-throughput microwell spectrometric platforms for the pharmaceutical analysis of RBX.

Methods: The two platforms, abbreviated as MW-AB and MW-FL, involved microwell-based analysis assisted with a multifunction microplate plate reader for measuring absorbance and fluorescence signals, respectively. The MW-AB and MW-FL platforms involved the formation of colored and fluorescent derivatives upon the reaction of RBX with oxidized pyrocatechol reagent (OPC) and tetracyanoquinodimethane (TCNQ), respectively. The absorbance of colored RBX-OPC derivative at 520 nm, and the fluorescence of RBX-TCNQ charge transfer complex at 283 and 484 nm for excitation and emission, respectively. The optimum conditions of both reactions were established, their molar ratios were determined, and reaction mechanisms were postulated.

Results: Both platforms were optimized and validated according to the guidelines of the International Council on Harmonization. The limits of quantitation were 19.6 µg/mL and 27 ng/mL for MW-AB and MW-FL, respectively. Both platforms were applied with excellent reliability to the quantitation of RBX content in Edranox® tablets and their drug uniformity. The greenness levels of both platforms were assessed by two comprehensive tools, and the results confirmed the high level of greenness for both platforms.

Conclusions: Both platforms involved one-step reactions, adapted microwell analysis, and simultaneous handling of large number of samples. Therefore, they have the advantages of greenness and high-throughput analysis.

Highlights: The proposed two platforms are valuable tools for the rapid quantitation of RBX.