Determination of non-steroidal anti-inflammatory analgesics in solid dosage forms by high-performance liquid chromatography on underivatized silica with aqueous mobile phase

A high-performance liquid chromatography procedure for the determination of selected non-steroidal anti-inflammatory analgesics (acetylsalicylic acid, fenbufen, fenoprofen, ibuprofen, indomethacin, ketoprofen, naproxen, sulindac and tolmetin) from pharmaceutical dosage forms has been developed. The individual analytes are extracted from the dosage forms with 0 to 10% aqueous acetonitrile and chromatographed on a 22-cm underivatized silica column at ambient temperature (23 ± 1°C). The mobile phases consisted of 5 mM aqueous sodium phosphate—phosphoric acid buffer, pH 2.6 containing 0 to 10% acetonitrile. Accuracy and precision of the method were shown to be excellent. This study was performed to extend the applicability of underivatized silica stationary support with aqueous eluents to the analysis of acidic compounds.