Simultaneous determination of arylpropionic acidic nonsteroidal anti-inflammatory drugs in pharmaceutical formulations and human plasma by HPLC with UV detection

A simple and sensitive high-performance liquid chromatography-UV detection method was developed for the simultaneous determination of non-steroidal anti-inflammatory drugs (NSAIDs) having an arylpropionic acid moiety in pharmaceutical formulations and human plasma. Isocratic separation was employed on ODS column (250 x 4.6 mm i.d., 5 mum) at ambient temperature. The mobile phase consisted of acetonitrile, phosphate buffer (pH 3.5; 50 mM), methanol and tetrahydrofuran. The NSAIDs in the eluent were monitored under a wavelength-programme to provide their maximum absorbance. Mefenamic acid was used as an internal standard. Drugs were found to be 96.8-101.9% of their label claim in pharmaceutical formulations. One hundred microliters of human plasma samples were pretreated with a simple liquid-liquid extraction using ethyl acetate. The detection limits of compounds studied at a signal-to-noise ratio of 3 were 11.5-75 ng/ml in human plasma samples. The proposed method is simple, selective and could be applicable for routine analysis of arylpropionic acidic NSAIDs in pharmaceutical as well as in human plasma samples. (C) 2002 Elsevier Science B.V. All rights reserved.