Macrocyclic Agents Remain Stable in Human Serum at pH 7.4 and 37˚C

  • There was no measurable release of gadolinium from any of the 3 macrocyclic agents when incubated in human serum at 37˚C for 15 days
  • There was no difference observed between the linear ionic agents Magnevist® and gadobenate dimeglumine, which released about 1.9% of their gadolinium after 15 days
  • The amount of gadolinium released from the linear nonionic agents reached around 20% after 15 days


Comparison of the amounts of gadolinium released from 1 mmol/L solutions of marketed GBCAs at 37˚C in native human serum from healthy volunteers


“The study confirmed the hypothesis that under physiological conditions, all GBCAs can be divided into 3 distinct stability classes, ie, the nonionic linear, ionic linear, and macrocyclic GBCAs (listed in order from lower to higher stability).”


This was an in vitro study designed to investigate the complex stability and gadolinium dissociation rate of all marketed gadolinium-based MRI contrast agents (GBCAs) under physiological conditions. The GBCAs were incubated in human serum at pH 7.4 and 37˚C for 15 days. The initial rates of gadolinium release and the total amounts of gadolinium released after 15 days were measured by HPLC-ICP-MS analysis.

(*) OptiMARK® is no longer marketed in Canada.