Changes in Chemical Structure of Iopamidol Contrast Agents According to Radiation and Environmental Conditions

Background: To prevent contrast agent’s side effects, it is important to provide accurate information about the contrast agent and fulfill the duty of explaining the medication, experience of side effects, and medical history. However, the incidence of safety accidents associated with contrast agents is continuously increasing. Therefore, the objective of this study was to prepare an improvement plan for problems derived by analyzing changes in chemical structure of contrast medium according to radiation and external environment. Method: The chemical structure of the standard sample was analyzed using Nuclear Magnetic Resonance Spectroscopy (NMR) in P contrast agent of Iopamidol preparations used in Korean medical institutions. Samples were obtained by irradiation under 3Gy and 5Gy conditions according to the Photon 10MV, Electron 20MeV condition and the radiation dose according to the radiation and environmental conditions. Contrast agent samples after opening and sealed but expired samples were also obtained. These samples were analyzed and chemical shift values in the 1H-NMR spectrum using NMR analysis were compared. Findings: 1H-NMR analysis results of P contrast medium irradiated with Photon 10MV and 5Gy and sealed but expired P contrast medium samples showed no change in chemical shift. However, there were changes in chemical shift value in P standard sample, showing triple peaks in 1.1-1.2ppm range. In addition, the sample irradiated by Electron 20MeV and 3Gy showed double peaks. The sample irradiated by Electron 20MeV and 3Gy condition showed a single peak in the 3.0-3.5ppm region, demonstrating a change in chemical shift value. In the 1.0-1.4ppm region, P contrast medium standard samples showed triple peaks and opened contrast medium samples showed double peaks in the middle peak among the triplet, demonstrating changes in chemical shift value. Improvements: Changes in chemical structure of contrast agent were observed in contrast medium after electron irradiation and in contrast medium after opening. In this regard, guidelines for the administration of contrast medium should be prepared as soon as possible so that consumers could have accurate information and their right of choice.