Physicochemical properties of iodixanol

Area of Science:

• Radiology and Imaging
• Medical Diagnostics
• Pharmacology

Background:

• Conventional monomeric radiopaque contrast media often exhibit high osmolality, potentially causing adverse effects.
• Nonionic contrast agents were developed to mitigate risks associated with ionic agents.
• There is a continuous need for improved contrast media with better safety profiles and physiological compatibility.

Purpose of the Study:

• To introduce iodixanol, a new nonionic dimeric contrast medium.
• To evaluate the physicochemical properties of iodixanol, including osmolality, viscosity, and hydrophilicity.
• To compare iodixanol with existing contrast agents like iohexol.

Main Methods:

• Characterization of iodixanol as a nonionic, dimeric roentgen contrast medium.
• Assessment of osmolality of iodixanol solutions at various concentrations.
• Measurement of viscosity and partition coefficients to determine hydrophilicity.
• Formulation adjustments using sodium and calcium salts to achieve isotonicity.

Main Results:

• Aqueous solutions of iodixanol exhibit lower osmolality compared to nonionic monomers.
• Iodixanol solutions can be rendered isotonic by adding sodium and calcium salts.
• The viscosity of iodixanol solutions is comparable to or less than iohexol (Omnipaque) 350 mg I/ml.
• Iodixanol demonstrates high hydrophilicity and good aqueous solubility due to its molecular structure.

Conclusions:

• Iodixanol offers an advantageous low osmolality profile, making it suitable for intravascular use.
• The dimeric structure contributes to improved physiological compatibility and isotonic formulation possibilities.
• Iodixanol represents a significant advancement in nonionic dimeric contrast media, potentially improving patient safety.