Alternative testing methods of radiopharmaceuticals in Czech Pharmacopoeia 2017 – Supplement 2021

Summary

Introduction: A new general monograph Alternative testing methods of radiopharmaceuticals has been published in Czech Pharmacopoeia 2017 – Supplement 2021. As these many other methods for a radiochemical purity (RCP) measurement are pharmacopoeial, they can be officially directly used in radiopharmaceuticals workplaces of medical establishments without a prior validation. A purpose of this article is to acquaint workers with mentioned methods and to emphasize an importance of a use of a pharmacopoeial recommended stationary phase in chromatography to achieve appropriate results on example of a frequent radiopharmaceutical [^99mTc]-oxidronate.

Method: A tabular statement of chromatographic methods for the radiochemical purity measurement of individual radiopharmaceuticals with supplement of desired values of the radiochemical purity and a calculation of the radiochemical purity in a case of more impurities. A paper radiochromatography using a scanner of chromatographic strips PT444R1. A radiopharmaceutical: [^99mTc]-oxidronate, a mobile phase: 0,9% NaCl, stationary phases: TLC-SP, 3MM Chr, 1 Chr (9 x 1 cm), a path length was 7 cm. A developed and scanned chromatogram was evaluated by software of the scanner.

Results: Tables summarizing chromatographic methods for the radiochemical purity measurement of the radiopharmaceuticals including the required values of the radiochemical purity and calculating formulas. A comparison of a distribution of [^99mTc]-oxidronate on TLC-SP, 3MM Chr, 1 Chr chromatograms revealed a regular chromatographic separation only on a chromatographic paper TLC-SP (Supelco™) recommended by the pharmacopoeia.

Conclusion: Stated chromatographic methods for the radiochemical purity measurement of the radiopharmaceuticals can be directly used instead of the ones stated for example in summaries of product characteristics (SPCs), which needn‘t be available in the workplace, such as an electrophoresis, a membrane filtration etc. An importance of a use of a specific commercial source of a chromatographic carrier resulted from an example of a [^99mTc]-oxidronate chromatography as using an other one doesn‘t ensure its availability and a responsible person is responsible for a confirmation of a suitability of other commercial brand of an adequate quality.

Keywords:

colloidal technetium-99m – pertechnetate-(99mTc) – bound technetium-99m – radiochemical purity – radiochemical impurities – [99mTc]technetium-oxidronate