In vivo performance of a liposomal vascular contrast agent for CT and MR-based image guidance applications

Pharm Res. 2007 Jun;24(6):1193-201. doi: 10.1007/s11095-006-9220-1. Epub 2007 Mar 21.

Abstract

Purpose: This study evaluated the in vivo performance of a liposome formulation that co-encapsulates iohexol and gadoteridol as a multimodal contrast agent for computed tomography (CT) and magnetic resonance (MR)-based image guidance applications.

Materials and methods: The pharmacokinetics and biodistribution studies were conducted in Balb-C mice using high performance liquid chromatography (HPLC) and inductively coupled plasma atomic emission spectrometry (ICP-AES) to detect iohexol and gadoteridol concentrations. The imaging efficacy of this liposome system was assessed in New Zealand White rabbits using a clinical CT and a clinical 1.5 Tesla MR scanner.

Results: The vascular half-lives of the liposome encapsulated iohexol and gadoteridol in mice were found to be 18.4 +/- 2.4 and 18.1 +/- 5.1 h. When administered at the same dose the distribution (alpha phase) half-lives for the free contrast agents were 12.3 +/- 0.5 min (iohexol) and 7.6 +/- 0.9 min (gadoteridol); while, the elimination (beta phase) half-lives were 3.0 +/- 0.9 h for free iohexol and 3.0 +/- 1.3 h for free gadoteridol. The CT and MR signal increases were measured and correlated with the concentrations of iohexol and gadoteridol detected in plasma samples.

Conclusion: The long in vivo circulation lifetime and simultaneous CT and MR signal enhancement provided by this liposome system make it a promising agent for image guidance applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Vessels / metabolism
  • Chromatography, High Pressure Liquid
  • Contrast Media*
  • Female
  • Liposomes*
  • Magnetic Resonance Imaging
  • Mice
  • Mice, Inbred BALB C
  • Pharmacokinetics
  • Tissue Distribution
  • Tomography, X-Ray Computed

Substances

  • Contrast Media
  • Liposomes