Bias in the measurement of radon gas using ionization chambers: Application to SIR.
Two main non-destructive techniques can be used to measure standard 222Rn gas ampoules: well-type ionization chambers and gamma-ray spectrometry, the former being used in the Système International de Référence (SIR) for international comparison purposes. The reliability of these techniques requires that the variability of the flame-sealed gas glass ampoules used have a negligible influence on the detector response. This variability is studied in this work by considering three parameters: the volume of the ampoule, the position of the sealing point and the thickness of the glass. Results showed that variability of the gas ampoules induced measurement bias larger than the uncertainty of the standard sources.
Compatibility of [99mTc]Tc-EDDA/HYNIC-TOC and [68Ga]Ga-DOTA-TOC in a syringe for intravenous administration.
OBJECTIVE
Drug quality in medical devices is not evaluated during the marketing authorization of radiopharmaceuticals. Therefore, the extemporaneous change of packaging made for preparation of patient unit doses in a syringe is the responsibility of radiopharmacists. The present study aimed to determine the impact of packaging and storage in a polypropylene syringe on the quality of hydrophilic drugs [Tc]Tc-EDDA/HYNIC-TOC (Tektrotyd) and [Ga]Ga-DOTA-TOC (Somakit-TOC).


METHODS
Appearance, pH, radiochemical purity, sterility, and endotoxin tests were performed according the current European Pharmacopoeia. Subvisible and visible particles tests of the European Pharmacopoeia were adapted due to limited preparation volume (<25 ml). Sorption tests were performed according to the literature.


RESULTS
After 2 h storage in a syringe, drug sorption of Tektrotyd and Somakit-TOC was of less than 2.5% and similar to other Tc-radiopharmaceuticals (range: from 1.1 ± 0.5% to 4.2 ± 0.6%). For Tektrotyd, this sorption phenomenon was positively influenced by the drug concentration and a short contact with the medical device (4.8 ± 0.2% up to 5 s vs. 2.3 ± 0.2%, n = 4; P < 0.001). For Somakit-TOC, the duration of contact with syringe had no impact (1.6 ± 0.2% up to 5 s vs. 1.7 ± 0.6%; P = 1.000). No drug radiolysis or alteration of microbiological aspects were observed. No impurity from a 3-piece-syringe was observed according to drug aspect, pH, and subvisible and visible particles, which remained within specification of the current European Pharmacopoeia.


CONCLUSION
This study found that drug sorption to packaging was compatible with clinical use and absence of drug alteration of Tektrotyd and Somakit-TOC after repackaging in a syringe in polypropylene and prolonged storage during 2 h.
KEY COMPARISON: Update of the BIPM comparison BIPM.RI(II)-K1.F-18 of activity measurements of the radionuclide 18 F to include the CIEMAT
Since 2001, six national metrology institutes (NMIs) have submitted six samples of known activity of 18 F to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), the most recent being that of the PTB (Germany). The activities ranged from about 1 MBq to 18 MBq. The key comparison reference value (KCRV) has been recalculated to include the latest value, with the agreement of the CCRI(II). The degrees of equivalence between each equivalent activity measured in the SIR have been recalculated and the results are given in the form of a matrix. A graphical presentation is also given for this key comparison with identifier BIPM.RI(II)-K1.F-18.