TECHNESCAN MAG3 Powder for solution for injection Ref.[11114] Active ingredients: Technetium ⁹⁹ᵐTc mertiatide

Technescan MAG3 is a kit for the preparation of technetium Tc 99m mertiatide, a diagnostic radiopharmaceutical. It is supplied as a sterile, nonpyrogenic, lyophilized powder. Each vial contains betiatide (N-[N-[N-[(benzoylthio) acetyl]glycyl]glycyl]glycine). After reconstitution with sterile sodium pertechnetate Tc 99m injection, the technetium Tc 99m mertiatide (disodium[N[N-[N-(mercaptoacetyl) glycyl]glycyl] glycinato (2-) - N,N′,N″,S′]oxotechnetate (2-)) which is formed is suitable for intravenous administration.

Each 10 milliliter vial contains 1 milligram betiatide, 0.05 milligram (minimum) stannous chloride dihydrate (SnCl₂•2H₂O) and 0.2 milligram (maximum) total tin expressed as stannous chloride dihydrate (SnCl₂•2H₂O), 40 milligrams sodium tartrate dihydrate (Na₂C₄H₂O₆•2H₂O), and 20 milligrams lactose monohydrate. Prior to lyophilization, sodium hydroxide or hydrochloric acid may be added for pH adjustment. The pH of the reconstituted drug is between 5.0 and 6.0. No bacteriostatic preservative is present. The contents are sealed under argon. Betiatide is light sensitive and must be protected from light. Betiatide and technetium Tc 99m mertiatide have the following structural formulas:

Physical characteristics

Technetium Tc 99m decays by isomeric transition with a physical half-life of 6.02 hours.?footnote?The principal photon that is useful for detection and imaging is listed in Table 1.

Table 1. Principal Radiation Emission Data¹:

¹ Kocher, David C., “Radioactive Decay Tables,” DOE/TIC-11026, 108 (1981).

The specific gamma ray constant for Technetium Tc 99m is 0.78 R/mCi-hr at 1 cm. The first half-value thickness of lead (Pb) for Technetium Tc 99m is 0.017 cm. 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 0.25 cm of Pb will decrease the external radiation exposure by a factor of about 1000.

Table 2. Radiation Attenuation by Lead Shielding

To correct for physical decay of the radionuclide, the fractions that remain at selected time intervals after the time of calibration are shown in Table 3.

Table 3. Physical Decay Chart: Technetium Tc 99m, Half-life 6.02 Hours

^* Calibration Time