Determination of imipenem and cilastatin in serum by high-pressure liquid chromatography

Abstract

Imipenem and cilastatin concentrations in serum were determined by using reverse-phase high-pressure liquid chromatography. Serum samples were stabilized with 0.5 M morpholineethanesulfonic acid buffer (pH 6.0) and subjected to ultrafiltration before chromatography. The elution solvent consisted of water or potassium phosphate buffered to pH 2.5 and methanol. The imipenem and cilastatin peaks were detected at 300 and 220 mm, respectively. Recovery from serum was 99% for imipenem and cilastatin; the limits of detectability for the 2 compounds were 0.3 and 0.5 .mu.g/ml, respectively. The assay may be readily applied to pharmacokinetic analysis of imipenem and cilastatin biodisposition in patients.