Rapid Determination of Meropenem in Biological Fluids by LC: Comparison of Various Methods for Sample Preparation and Investigation of Meropenem Stability

A rapid and sensitive LC-UV method was developed and validated for the determination of meropenem, in human plasma and urine. Meropenem retention time was 4.8 min. Method development was based on comparative analysis of different extraction methods published as well as careful study of meropenem stability in biological samples under different conditions. Best results in plasma sample preparation were obtained from protein precipitation with methanol. LOQ was 0.1 A mu g mL(-1) for plasma and 1 A mu g mL(-1) for urine samples. Meropenem in plasma has low stability at room temperature (< 20% of original content after 12 h), but had acceptable stability when the whole analysis procedure was designed to minimize the exposure of meropenem-containing samples and solutions to temperatures higher than 4 A degrees C. The developed method was applied to a human pharmacokinetic study in patients with acute peritonitis.