Quantification of meropenem in plasma and cerebrospinal fluid by micellar electrokinetic capillary chromatography and...

A high-performance micellar electrokinetic capillary chromatography (MEKC) has been demonstrated for the determination of meropenem in human plasma and in cerebrospinal fluid (CSF) and application in meningitis patients after intravenous (IV) administration. Plasma sample was pretreated by means of solid-phase extraction (SPE) on C(18) cartridge and CSF sample was by direct injection without sample pretreatment, with subsequent quantitation by MEKC. The separation of meropenem was carried out in an untreated fused-silica capillary (40.2 cm x 50 microm I.D., effective length 30 cm) and was performed at 25 degrees C using a background electrolyte consisting of Tris buffer (40 mM, pH 8.0) solution with sodium dodecyl sulfate (SDS) as the running buffer and on-column detection at 300 nm. Several parameters affecting the separation and sensitivity of the drug were studied, including pH, the concentrations of Tris buffer and surfactant. Using cefotaxime as an internal standard (IS), the linear ranges of the method for the determination of meropenem in plasma and in CSF were all over 0.5-50 microg/mL; the detection limits (signal-to-noise ratio=3) of meropenem in plasma and in CSF were 0.2 microg/mL and 0.3 microg/mL, respectively.