title: Usefulness of residual fractions of L,L-ethylcysteinate dimer (Neurolite) for the preparation of 99Tc(m)-L,L-ethylcysteinate dimer.
abstract: According to the reconstitution instructions for the Neurolite labelling kit, the contents of vial A (containing the ligand) is dissolved in 3 ml of saline and 1 ml of the solution is added to vial B (containing 1 ml of phosphate buffer) to which 2 ml of 99Tc(m) generator eluate had previously been added. This implies that 2 out of 3 ml of the ligand solution is not used. We have investigated the radiochemical purity of 99Tc(m)-ECD reconstituted from fractions of the residual solution after storage in a freezer. Fractions of 0.25 ml or 0.5 ml were reconstituted with 1.11 GBq or 3.7 GBq 99Tc(m)-pertechnetate, respectively, after storage at -20 degrees C for periods ranging from 1 day to 4 weeks. In each test situation, except when 0.25 ml fractions were labelled with 3.7 GBq 99Tc(m), 99Tc(m)-ECD was obtained with a radiochemical purity > 95% up to 6 h after reconstitution, as determined using two-strip TLC and reverse-phase HPLC. The results demonstrate that residual portions of Neurolite kits can be efficiently labelled after fractionation and storage in a freezer.
authors.affiliation: Laboratory of Radiopharmaceutical Chemistry, Catholic University of Leuven, University Hospital Gathuisberg, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Verbeke
authors.forename: C
authors.initials: C
authors.lastname: Boonen
authors.forename: A
authors.initials: A
authors.lastname: Verbruggen
mesh_terms: D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000031:analogs & derivatives*; D004355:Drug Stability; D005615:Freezing; D006801:Humans; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D011933:Reagent Kits, Diagnostic; D013670:Sodium Pertechnetate Tc 99m; D013997:Time Factors; D014055:Tomography, Emission-Computed
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D011933:Reagent Kits, Diagnostic; D013670:Sodium Pertechnetate Tc 99m; C059659:technetium Tc 99m bicisate; D003545:Cysteine