Determination of meropenem levels in human serum by high-performance liquid chromatography with ultraviolet detection

Meropenem is a β-lactam broad-spectrum antibiotic and belongs to the subgroup of carbapenems. It is primarily used in intensive care units for intravenous treatment of severe infections. To avoid bacterial resistance or toxic side effects, the determination of serum meropenem concentration is highly advisable. A simple and fast method for the quantitative determination of meropenem in human serum using high-performance liquid chromatography with ultraviolet detection (HPLC/UV) was developed and validated. Meropenem was determined by an isocratic HPLC using a tris(hydroxymethyl)aminomethane buffer (pH 8.5; 15% methanol) as a mobile phase and UV detection at 300 nm, with a flow rate of 1.0 mL/min and an analysis time of 10 min. Chromatographic separation was performed on a Kinetex C₁₈ column (5 μm, 150 × 4.6 mm). In order to remove undesired serum components, solid-phase extraction was used for sample preparation. Since meropenem is not stable in solution, sample and stock solution were stored at -80°C. After preparation, samples were stable at room temperature for at least 6 h. The calibration curve was linear from 3.5 to 200 mg/L with a correlation coefficient r² of 0.999. The method is accurate with an intra- and inter-assay precision <18.5%.