Development and validation of charge transfer based spectrophotometric method for the quantification of bromocriptine mesylate in pharmaceutical formulations

Ali, Alaa E; Gouda, Ayman A.; Elasala, Gehan S.; Emam, Basant S.; Afify, Mohamed A.

doi:10.22034/crl.2025.531272.1640

Development and validation of charge transfer based spectrophotometric method for the quantification of bromocriptine mesylate in pharmaceutical formulations

Document Type : Research Article

Authors

Alaa E Ali ¹

Ayman A. Gouda ²

Gehan S. Elasala ¹

Basant S. Emam ¹

Mohamed A. Afify ²

¹ Chemistry Department, Faculty of Science, Damanhur University, Damanhour, Egypt

² Department of Chemistry, Faculty of Science, Zagazig University, Zagazig, 44519, Egypt

https://doi.org/10.22034/crl.2025.531272.1640

Abstract

This study seeks to develop and validate two straightforward, sensitive, accurate, and cost-effective spectrophotometric techniques for detecting bromocriptine mesylate, an anti-parkinsonian medication, in its pure form and in pharmaceutical formulations. The methods rely on establishing a charge transfer complex between bromocriptine mesylate as the n-donor and either quinalizarin (Quinz) and alizarin red S (ARS) as π-acceptors in methanol. This results in the formation of highly colored chromogens with absorption maxima at 551 and 521 for Quinz and ARS, respectively. The study examined the optimization of reaction parameters. The stoichiometric ratio of the produced charge transfer complexes was determined to be 1:1 (bromocriptine mesylate:reagent) using Job's method of continuous variation for both approaches. Beer’s law was followed within the concentration ranges of 1.0–20 and 1.0–24 μg mL⁻¹ using Quinz and ARS, respectively, under optimum circumstances. This assertion is supported by a significant correlation coefficient (r² > 0.9992) and a low relative standard deviation (RSD% < 0.84). The detection and quantification limits were set at 0.30 and 1.0 μg mL-1 for both reagents. The proposed approaches were effectively utilized to quantify bromocriptine mesylate in pure form and pharmaceutical formulations, and the validity was assessed using the standard addition technique.

Graphical Abstract