Lyophilization of NOTA-sdAbs: First step towards a cold diagnostic kit for 68Ga-labeling

Onderzoeksoutput: Articlepeer review

2 Citaten (Scopus)
176 Downloads (Pure)


Lyophilization is commonly used in the production of pharmaceutical compounds to increase the stability of the Active Pharmaceutical Ingredient (API) by removing solvents. This study investigates the possibility to lyophilize an anti-HER2 and an anti-MMR single-domain antibody fragment (sdAb)-based precursor as a first step in the development of a diagnostic kit for PET imaging.

METHODS: NOTA-sdAb precursors have been lyophilized with the following formulation: 100 µg NOTA-sdAb in 0.1 M NaOAc (NaOAc), 5% (w/v%) mannitol-sucrose mix at a 2:1 ratio and 0.1 mg/mL polysorbate 80. During development of the formulation and drying cycle, factors such as cake appearance, glass transition temperature and residual moisture were analyzed to ensure qualitative and stable lyophilized samples. Stability studies of lyophilized precursor were conducted up to 18 months after storage at 2-8 °C by evaluating the precursor integrity, aggregation, functionality and 68Ga-labeling efficiency. A comparative biodistribution study (lyophilized vs non-lyophilized precursor) was conducted in wild type mice (n = 3) and in tumor bearing mice (n = 6).

RESULTS: The lyophilized NOTA-anti-HER2 precursor shows consistent stability data in vitro for up to 12 months at 2-8 °C in three separate batches, with results indicating stability even for up to T18m. No aggregation, degradation or activity loss was observed. Radiochemical purity after 68Ga-labeling is consistent over a period of 12 months (RCP ≥ 95% at T12m). In vivo biodistribution analyses show a typical [68Ga]Ga-NOTA-anti-HER2 sdAb distribution profile and a comparable tumor uptake for the lyophilized compound vs non-lyophilized (5.5% vs 5.7 %IA/g, respectively). In vitro results of lyophilized NOTA-anti-MMR precursor indicates stability for up to 18 months, while in vivo data show a comparable tumor uptake (2.5% vs 2.8 %IA/g, respectively) and no significant difference in kidney retention (49.4% vs 47.5 %IA/g, respectively).

CONCLUSION: A formulation and specific freeze-drying cycle were successfully developed to lyophilize NOTA-sdAb precursors for long-term storage at 2-8 °C. In vivo data show no negative impact of the lyophilization process on the in vivo behavior or functionality of the lyophilized precursor. These results highlight the potential to develop a kit for the preparation of 68Ga-sdAb-based radiopharmaceuticals.

Originele taal-2English
Pagina's (van-tot)194-204
Aantal pagina's11
TijdschriftEuropean Journal of Pharmaceutics and Biopharmaceutics
StatusPublished - sep 2021

Bibliografische nota

Funding Information:
Funding sources solely provided financial support for the research.

Funding Information:
This work has received support from the Industrial Research Fund (IOF), Scientific Fund W. Gepts UZ Brussel, IWT TBM (IWT.150198), Flemish League against Cancer, Foundation against Cancer and Fund for Scientific Research (FWO). M.K. and T.L. are senior clinical investigators of the Research Foundation-Flanders (FWO). J.B. is funded by the EU H2020 Marie Skłodowska-Curie Actions MSCA ITN PET3D N675417 and by the Scientific Fund W. Gepts UZ Brussel.

Publisher Copyright:
© 2021 The Authors

Copyright 2021 Elsevier B.V., All rights reserved.


Duik in de onderzoeksthema's van 'Lyophilization of NOTA-sdAbs: First step towards a cold diagnostic kit for 68Ga-labeling'. Samen vormen ze een unieke vingerafdruk.

Citeer dit