RESUMO
BACKGROUND: Automated dispensing systems (ADSs) for radiopharmaceuticals have been developed to reduce the radiation exposure of personnel, to improve the accuracy of the dispensed dose and to limit the microbiological contamination. However, before implementing such systems, validation according to various applicable guidelines is necessary to ensure safety and quality. Here we present the selection, validation and implementation of the PT459R2 from manufacturer Lynax s.r.o. as a guidance protocol for validation according to GMP and GRPP guidelines. Validation included linearity accuracy and precision of the internal scintillation detector for different isotopes and microbiological validation for aseptic procedures. RESULTS: The ADS can dispense accurate doses in the following linear range: 1000-10,000 MBq for lutetium-177, 20-74 MBq for zirconium-89, 100-1000 MBq for gallium-68 and 100-2000 MBq for fluorine-18. The maximum bias is 2.35% and the maximum coefficient of variation is 3.03% which meets the acceptance criteria of < 5%. Furthermore, the ADS does not affects the GMP class A environment in a laminar airflow cabinet and can dispense aseptically. In addition, radiation exposure is acceptable and data integrity is preserved. CONCLUSION: The PT459R2 ADS met all the requirements from our performance qualification and is therefore suitable for daily routine use in our center. Our approach can be used as a guidance for PQ of an ADS in a Radiopharmacy according to GMP and GRPP guidelines.
RESUMO
Lutetium-177 [177Lu] tetra-azacyclododecanetetra-acetic acid [DOTA]-(Tyr3)-octreotate [TATE] ([177Lu]Lu-DOTA-TATE) is a radiopeptide used for peptide receptor radionuclide therapy in patients with neuroendocrine tumours (NETs). This radiopeptide is made by labelling the ligand octreotate with Lutetium-177 using the linker DOTA. After labelling, and before clinical application quality control of the radiopeptide is needed and the radiochemical purity is assessed. Acceptance limits for radiochemical purity should be within 90-110% of the label claim for radiopharmaceuticals for diagnostic use and within 95-105% of the label claim for radiopharmaceuticals for therapeutic use. Moreover, the amount of unlabelled [177Lu]LuCl3 cannot exceed 2% of the radioactive dose. Since no monograph is available for [177Lu]Lu-DOTA-TATE in the European Pharmacopeia (Ph Eur), this article describes the development and validation of a high-performance liquid chromatography (HPLC) method with ultraviolet (UV) detection and radiodetection. A Waters Acquity Arc UHPLC system equipped with a Waters 2998 photodiode array (PDA) detector was used coupled to a Berthold Lb 514 Flowstar detector equipped with a BGO-X gamma measuring cell. A reversed phase Symmetry Shield C18 column (4.6 mm × 250 mm, 5 µm) was used for chromatographic separation. A flow of 1.5 mL/min was maintained during analysis, using 0.1% TFA in water as mobile phase A and 0.1% TFA in ACN as mobile phase B. The retention time was around 1.7 min and 13.5 min for [177Lu]LuCl3 and [177Lu]Lu-HA-DOTA-TATE, respectively. Stock solutions of [177Lu]LuCl3 were made by serial dilution and were injected to test for linearity, accuracy and precision, carry over and signal-to-noise ratio. A [177Lu]Lu-HA-DOTA-TATE sample was prepared and injected to determine the carry over. The results showed that the method is linear over a range of 0.300-130 MBq/mL, which covers the range for clinical samples, provided that the clinical sample is diluted ten times before analysis. The LLOQ can be measured accurately even after dilution, with a signal-to-noise ratio of at least 5. In short, the method is accurate, precise and sensitive and can be implemented as part of the quality control of [177Lu]Lu-HA-DOTA-TATE.
