Objective: To determine whether or not there is any interaction between iopamidol and gadopentetate dimeglumine (Gd-DTPA) in test tubes using the direct mixing manner.
Materials and methods: The test solution was prepared by mixing iopamidol (Iopamiron 300) and Gd-DTPA (Magnevist) at a ratio of 1:1. The color, viscosity, and pH of the mixed solutions were assessed immediately after mixing and 1,3,6, and 24 hours after mixing. The concentration of aromatic primary amines, content of iopamidol, concentration of free iodine ion, and content of Gd-DTPA in the mixed solution were determined, and the presence or absence of spots, other than those resulting from iopamidol and Gd-DTPA, was determined using thin layer chromatography. These tests were carried out immediately, and 24 hours after mixing. Using iopamidol alone and Gd-DTPA alone as controls, the same items were examined.
Results: There was no significant change in the appearance or pH of the mixed iopamidol and Gd-DTPA solution immediately and 1, 3, 6, and 24 hours after direct mixing. The study of iopamidol alone or Gd-DTPA alone showed no apparently abnormal values or findings.
Conclusion: The direct mixing of iopamidol and Gd-DTPA in a test tube results in no significant interaction.