Comparison between sodium dodecylsulphate and cetyltrimethylammonium bromide as mobile phases in the micellar liquid chromatography determination of non-steroidal anti-inflammatory drugs in pharmaceuticals

The retention behaviour of non-steroidal anti-inflammatory drugs (NSAIDs) using micellar mobile phases of sodium dodecylsulphate (SDS) is studied and compared with that observed with micellar mobile phases of cetyltrimethylammonium bromide (CTAB). A liquid chromatographic procedure for the determination of acemetacin, diclofenac, indomethacin, ketoprofen, naproxen and tolmetin in pharmaceutical preparations is described. The proposed system uses a Kromasil C-18 analytical column and a solution of 0.15 M SDS at pH 3 with 10% 1-propanol as mobile phase. Under these conditions, the studied NSAIDs elute between 6 and 10 min at a 1 mL min(-1) flow rate. Limits of detection (LOD) are lower than 0.5 mug mL(-1). Recoveries in the analysis of the pharmaceutical preparations are ranged between 91 and 104% respect to the nominal content declared by the manufacturers and the relative standard deviations are in general lower than 4%. (C) 2004 Elsevier B.V. All rights reserved.