RESUMO
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 microm) 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.