HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ASSAY OF THE MAGNETIC-RESONANCE-IMAGING CONTRAST AGENT GADOBENATE IN PLASMA, URINE AND BILE

Gadobenate dimeglumine (Gd-BOPTA-Dimeg) is currently under evaluation as an intravascular paramagnetic contrast agent for magnetic resonance imaging. The anion Gd-BOPTA(2-) is the moiety of Gd-BOPTA-Dimeg respo nsible for contrast enhancement. An HPLC method for assaying gadobenat e (Gd-BOPTA(2-)) in plasma, urine and bile samples is described. The a nalysis is based on the reversed-phase chromatographic separation of t he ion pair Gd-BOPTA(2-)-tetrabutylammonium from the endogenous compon ents of biological fluids and its detection by UV absorption at 210 nm . The mean accuracy and precision of the method were in the range -3.4 to +5.0% and 0.2-3.5%, respectively. The method detection limits for Gd-BOPTA(2-) in plasma (0.8 ml), urine (0.2 ml) and bile (1.0 ml) were 1.1, 7.6 and 1.7 mu M (corresponding to 0.73, 5.1 and 1.1 mu g/ml), r espectively.