Rapid and Sensitive Liquid Chromatographic Assay of Mefenamic Acid in Plasma

摘要

Mefenamic acid (MA) is a nonsteroidal antiinflammatory analgesic agent widely used clinically. A simple and sensitive liquid-chromatographic assay has been developed for the quantitative determination of MA in human plasma. A reverse phase, 10-mu;m cyano column (25 times; 0.4 cm), a mobile phase of water-acetonitrile-methanol-17Macetic acid (69:15:15:1 by volume), and an ultraviolet detection (290 nm) are used for the separation of MA and internal standard (methyl-clonazepam). MA and internal standard are extracted from acidified plasma into diethyl ether and after evaporation of the organic phase, the residue is redissolved in methanol. Calibration curves are linear in the range 0.05ndash;3.20 mu;g/ml, and at the plasma level corresponding to the quantification limit (0.05 mu;g/ml) coefficients of variation are 7.5percnt; and 10.2percnt; for repeatibility and reproducibility studies, respectively. This assay was successfully used in the study of pharmacokinetics of MA in human plasma after a single oral administration of a low MA dose.