Determination of the novel sialic acid analog GG167 (GR121167X) in human urine by liquid chromatography: direct injection with column switching.

GG167 is a novel compound which selectively inhibits viral neuraminidase and has demonstrated activity against influenza A and B. A liquid chromatography (LC) method for the determination of GG167 in human urine has been developed and validated. The method allows direct injection of urine (7 microliters) using LC column switching followed by UV detection. Initial chromatography is performed using a Nucleosil-Diol column (7 microns, 250 mm x 4.6 mm), eluted with 20 mM phosphate buffer (pH 2.5):acetonitrile (18:82, v/v) at 2.0 ml min-1. GG167 is "heart-cut" to a Spherisorb-SCX column (5 microns, 100 mm x 4.6 mm) and eluted with 35 mM phosphate buffer (pH 2.5):acetonitrile (50:50, v/v) at 1.5 ml min-1 for final separation. GG167 is detected by UV absorbance at lambda = 238 nm. UV detection and peak shape are enhanced at pH < 2.5. The quantitation range of the assay is 0.3-100 micrograms ml-1. The method has demonstrated sufficient ruggedness to be used in support of GG167 clinical trials.