Development and validation of an HPLC-UV method for iodixanol quantification in human plasma

Iodixanol is a widely used iso-osmolar contrast medium agent. Similar to iohexol, it can also be a good exogenous marker for the measurement of glomerular filtration rate (GFR). This article describes the development and validation of an HPLC-UV method for quantification of iodixanol in human plasma. internal standard, iohexol (20 mu l, 1 mg/ml), and perchloric acid (30 mu l, 20%, v/v) were added to plasma samples (300 mu l), followed by neutralization with 10 mu l potassium carbonate (5M). Samples were centrifuged and 10 mu l of the supernatant was injected onto a C-18 EPS analytical column (3 mu m particle size, 150 mm x 4.6 mm). The extraction method yielded > 95% recovery for both iodixanol and iohexol. The mobile phase consisted of 0.1% (w/v) sodium formate buffer and acetonitrile. Iohexol and iodixanol peaks were eluted at similar to 5 and 9 min, respectively using a fast gradient method. The assay lower limit of detection was 2.0 mu g/ml and lower limit of quantification was 10 mu g/ml. The calibration curves, assessed in six replicates, were linear over an iodixanol concentration range of 10-750 mu g/ml. Intra- and inter-day accuracy was > 95% and precision expressed as % coefficient of variation was < 10%. This method is simple, accurate, precise and robust and can potentially be used for iodixanol quantification in large-scale clinical studies. (c) 2008 Elsevier B.V. All rights reserved.