Development and Evaluation of User-Friendly Single Vial DOTA-Peptide Kit Formulations, Specifically Designed for Radiolabelling with68Ga from a Tin Dioxide68Ge/68Ga Generator.
This study was aimed to develop single vial 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-peptide kits to be used with fractionated eluates from a SnO2-based68Ge/68Ga generator.



Kits were formulated with 35 μg DOTA-Tyr3-Thre8-octreotide, DOTA-[Tyr3]-octreotide and DOTA-[NaI3]-octreotide (DOTATATE, DOTATOC and DOTANOC) and sodium acetate powder, vacuum-dried and stored at -20 °C for up to 12 months. Labelling of the kits was carried out with 2 ml68Ga eluate. Comparative labelling was carried out using aqueous DOTA-peptide stock solutions kept frozen at -20 °C for up to 12 months.



The quality of the kits was found to be suitable over a 1-year storage period (pH, sterility, endotoxin content, radiolabelling efficiency and radiochemical yields of68Ga-labelled DOTA-peptides). Radiochemical yields ranged from 73 to 83 %, while those obtained from stock solutions from 64 to 79 %. No significant decline in kit labelling yields was observed over a 12-month storage period.



The single vial kit formulations met the quality release specifications for human administration and appear to be highly advantageous over using peptide stock solutions in terms of stability and user-friendliness.
Radionuclide Production Department, iThemba LABS, PO Box 722, Somerset West, 7129, South Africa. deidre@tlabs.ac.za.
Deidré
D
Prince
Radionuclide Production Department, iThemba LABS, PO Box 722, Somerset West, 7129, South Africa.
Daniel
D
Rossouw
Radionuclide Production Department, iThemba LABS, PO Box 722, Somerset West, 7129, South Africa.
Claudia
C
Davids
Nuclear Medicine Division, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa.
Sietske
S
Rubow
D002851:Chromatography, High Pressure Liquid; D005857:Germanium / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015282:Octreotide / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D019275:Radiopharmaceuticals / Q000138:chemical synthesis*; D011933:Reagent Kits, Diagnostic; D017971:Tin Compounds / Q000737:chemistry*
C587879:68Ga-DOTA-octreotide; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; D011933:Reagent Kits, Diagnostic; D017971:Tin Compounds; D005857:Germanium; C045358:stannic oxide; D015282:Octreotide
68Ga eluate; DOTA-peptides; Radiochemical yields; Radiolabelling efficiency; Single vial kit; SnO2-based 68Ge/68Ga generator