Development and validation of a fast reversed-phase ion-pairing liquid chromatographic method for simultaneous determination of eight cephalosporin antibiotics in pharmaceutical formulations

A fast and reliable single method was developed for rapid screening of cephalosporin oral dosage forms aimed to the detection of counterfeit and substandard drugs that might be illegally commercialised. Nine cephalosporin compounds, ceftibuten, cefatrizine, cefadroxil, cefaclor, cefprozil (Z) and (E)-isomers, cefixime, cephalexin and cefradine were separated in a six minutes chromatographic run by using a Symmetry(R) C18 column (50 x 4.6 mm I.D., 3.5 mum particle size) and an UV detector set at 254 nm. The mobile phase consisted of a mixture of acetonitrile-methanol-phosphate buffer (50 mM) containing 1-pentanesulfonic acid sodium salt (7 mM) adjusted to pH = 2.1 with phosphoric acid (9:13:78 v/v/v). Validation of the method showed it to be robust, precise, accurate and linear over the concentration range of analysis.