Differential Spectrophotometric Determination of Levofloxacin in Bulk and Pharmaceutical Formulations
DOI:
https://doi.org/10.51412/psnnjp.2026.003Keywords:
Levofloxacin, Method Validation, Determination, Differential Ultraviolet SpectrophotometryAbstract
Background: Levofloxacin, which is pharmaceutically available as a hemihydrate (C18H20FN3O4 ·1/2H2O), is the optical S-(-) isomer of ofloxacin. This study proposed and validated a differential ultraviolet spectrophotometric method for determining levofloxacin in bulk and pharmaceutical formulations, based on the principle that levofloxacin exhibits characteristic spectral shifts with changes in the pH of the assay solvents.
Methods: Two solutions of levofloxacin in 0.1N HCl and 0.1N NaOH at the same concentration served as the test and reference solutions (∆D1), and as the reference and test solutions (∆D2). The amplitude values were calculated and plotted against concentrations.
Results: Beer's law was obeyed, and the calibration curves were found to be linear over the concentration range of 4–20 μg/mL, with an excellent correlation coefficient (r > 0.9999) for both scenarios at the observed absorption maxima and minima of 228 and 298 nm for ∆D1, and 257 and 348 nm for ∆D2. Accuracy studies showed recoveries close to 100% (100.17–100.35%) with low RSD values (≤1.78%), demonstrating excellent accuracy. Precision was also satisfactory, with intraday precision and robustness RSD values generally below 2%. Sandell's sensitivity (0.0113–0.0166 µg·cm⁻²) indicated adequate analytical sensitivity.
**Conclusion:** The results indicate that the proposed analytical method is accurate, specific, and precise, and can be used for routine analysis of levofloxacin hemihydrate in bulk and pharmaceutical formulations.
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Copyright (c) 2026 Sa'ad Toyin Abdullahi, Faith Oluwanifemi Dada, Oluwasegun Ibrahim Eniayewu, Olasunkanmi David Bamidele, Abdulrazaq Sanusi, Abdulrazaq Sanusi, Fatima Mohammad Madaki, Julius Olugbenga Soyinka

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