Rubratope-57
Generic name: cyanocobalamin CO-57
Dosage form: Diagnostic capsules
Medically reviewed by Drugs.com. Last updated on Feb 21, 2022.
On This Page
Rubratope-57 Description
DESCRIPTION Rubratrope-57 diagnostic capsules for oral administration provide radioactive cyanocobalamin in which a portion of the molecules contain Co 57 in the molecular structure vitamin B12-57Co. The chemical structure of cyanocobalamin is given below:
Each Rubratope-57 capsule contains approximately 18.5 to 37 kBq (0.5 to 1.0 microcurie) of cyanocobalamin Co 57; the cyanocobalamin content of each capsule will vary with the specific activity of the cyanocobalamin Co 57 used. Complete assay data are provided on the vial label.
PHYSICAL CHARACTERISTICS
Cobalt 57 decays by electron capture with a physical half-life of 270.9 days.1 Photons that are useful for detection and imaging studies are listed in Table 1.
| Principal Radiation Emission Data | ||
Radiation | Mean % per Disintegration | Mean Energy (keV) |
| Gamma-2 | 85.5 | 122.1 |
| Gamma-3 | 10.6 | 136.5 |
- 1
- Kocher, David C., “Radioactive Decay Data Tables”, DOE/TIC-11026, (1981) p.77.
External Radiation
The specific gamma ray constant for Co 57 is 0.96 R/hour-millicurie at 1 cm. The first half-value thickness of Pb (lead) for Co 57 is 0.006 cm. To facilitate control of the radiation exposure, a range of values for the relative attenuation of the radiation emitted by this radionuclide that results from interposition of various thicknesses of Pb is shown in Table 2. For example, the use of 1.6 cm of Pb will decrease the external radiation exposure by a factor of about 1,000.
| Radiati
MEDICAL DEPARTMENTS
Cardiology
Pediatrics
Diabetes Care
Pre-natal Care
Ultrasound Echocardiogram
|
