Voriconazole, a pivotal antifungal agent, has been analysed using two uncomplicated, sensitive, rapid, and validated spectrophotometric methods. These procedures rely on the formation of charge transfer complexes in methanol, employing alizarin red S and quinalizarin as chromogenic reagents, each exhibiting absorption maxima at 568 and 513 nm, respectively. The optimisation of reaction conditions was explored, encompassing the choice of solvent, reagent concentration, and reaction duration. Both alizarin red S and quinalizarin demonstrated excellent adherence to Beer's law over concentration ranges of 1.0-18 and 1.0-24 µg mL-1, respectively, with robust correlation coefficients (r2 ≥ 0.9993) and minimal relative standard deviations (RSD% ≤ 1.04). Additionally, calculations were conducted for molar absorptivity (1.1256×104 and 1.7624 ×104 L mol-1 cm-1), Sandell sensitivity (31.0 and 19.82 ng cm-2), detection and quantification limits (0.3 and 1.0 µg mL-1) for alizarin red S and quinalizarin, respectively. Both methods were effectively applied for the determination of voriconazole in dosage forms, and their validity was confirmed using the standard addition technique. The results obtained from these proposed procedures for pure and dosage forms closely matched those from previously reported methods.

KEY WORDS: Voriconazole, Spectrophotometry, Charge transfer complex, Dosage forms, Method validation.

Bull. Chem. Soc. Ethiop. 2025, 39(2), 189-200.                                                             

DOI: https://dx.doi.org/10.4314/bcse.v39i2.1