A new (68)Ga anionic concentration and purification method for automated synthesis of [(68)Ga]-DOTA or NODAGA conjugated peptides in high radiochemical purity

J Labelled Comp Radiopharm. 2015 Aug;58(10):403-10. doi: 10.1002/jlcr.3316. Epub 2015 Aug 4.

Abstract

The (68)Ge/(68)Ga generator is of increasing interest for clinical PET. For successful labelling, the eluate has to be purified. The aim of our approach is to improve the existing anionic methods which have a number of advantages compared to other methods but which use high concentrated HCl, and require an additional anionizing step. A new (68)Ga-eluate anionic purification method that enables rapid and high efficiency labelling of DOTA and NODAGA conjugated peptides in high radiochemical purity is described. The new method uses NaCl as an alternative Cl(-) source to the corrosive HCl and combines the three standard steps in a single step. The recovery yield was ≥90%, and the (68)Ge breakthrough was in conformity with the European Pharmacopeia limit. An automated labelling of DOTA and NODAGA-conjugated peptides was performed with the new method, using acetate sodium buffer, with a total duration of 13 min and a radiochemical yield >85%. The labelled peptides have a radiochemical purity exceeding 99% and can be used directly without any further purification step and without the quality control by gas chromatography. Furthermore, the new method has an economic advantage: it offers the possibility to use generator until 20 months after the calibration date.

Keywords: DOTA; NODAGA; NaCl; anionic purification; gallium 68; peptides.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / chemical synthesis*
  • Anions / chemistry
  • Automation / instrumentation
  • Automation / methods*
  • Chemistry Techniques, Synthetic / instrumentation
  • Chemistry Techniques, Synthetic / methods*
  • Heterocyclic Compounds, 1-Ring / chemical synthesis*
  • Organometallic Compounds / chemical synthesis*
  • Peptides / chemistry
  • Radiopharmaceuticals / chemical synthesis*

Substances

  • 1-(1,3-carboxypropyl)-4,7-carboxymethyl-1,4,7-triazacyclononane
  • 68Ga-DOTANOC
  • Acetates
  • Anions
  • Heterocyclic Compounds, 1-Ring
  • Organometallic Compounds
  • Peptides
  • Radiopharmaceuticals