A Rapid, Simple, and Validated RP-HPLC Method for Quantitative Analysis of Levofloxacin in Human Plasma

Abstract

To conduct a bioequivalence study for a copy product of levofloxacin (LEV), a simple and validated analytical method was needed, but the previous developed methods were still too complicated. For this reason, a simple and rapid high performance liquid chromatography method was developed and validated for LEV quantification in human plasma. Chromatographic separation was performed under isocratic elution on a Luna Phenomenex® C18 (150 × 4.6 mm, 5 µm) column. The mobile phase was comprised of acetonitrile, methanol, and phosphate buffer 25 mM that adjusted at pH 3.0 (13:7:80 v/v/v) and pumped at a flow rate of 1.5 mL/min. Detection was performed under UV detector at wavelength of 280 nm. Samples were prepared by adding acetonitrile and followed by centrifugation to precipitate plasma protein. Then followed successively by evaporation and reconstitution step. The optimized method meets the requirements of validation parameters which included linearity (r = 0.995), sensitivity (LLOQ and LOD was 1.77 and 0.57 µg/mL respectively), accuracy (%error above LLOQ ≤ 12% and LLOQ ≤ 20%), precision (RSD ≤ 9%), and robustness in the ranges of 1.77-28.83 µg/mL. Therefore, the method can be used as a routine analysis of LEV in human plasma as well as in bioequivalence study of LEV.

Keywords

• levofloxacin
• HPLC-UV
• validation
• human plasma