TECHNESCAN HDP Powder for solution Ref.[10994] Active ingredients: Technetium ⁹⁹ᵐTc oxidronic acid

Technescan HDP is supplied as a lyophilized powder, packaged under nitrogen in vials for intravenous administration after reconstitution with ADDITIVE-FREE sodium pertechnetate Tc 99m. Each vial contains 3.15 mg oxidronate sodium and 0.258 mg, minimum, stannous chloride (SnCl₂•2H₂O), 0.297 mg, theoretical, stannous chloride (SnCl₂•2H₂O) with 0.343 mg, maximum, tin chloride [stannous and stannic] dihydrate as SnCl₂•2H₂O as active ingredients. In addition, each vial contains 0.84 mg gentisic acid as a stabilizer and 30.0 mg sodium chloride. The pH is adjusted with hydrochloric acid and/or sodium hydroxide. The pH of the reconstituted drug is between 4.0 and 5.5. The contents of the vial are sterile and non-pyrogenic.

The chemical structure of oxidronate sodium is:

This radiopharmaceutical diagnostic agent, when reconstituted with ADDITIVE-FREE sodium pertechnetate Tc 99m forms a complex of unknown structure.

Physical characteristics

Technetium Tc 99m decays by isomeric transition with a physical half-life of 6.02 hours.¹ 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 Data Tables,” DOE/TIC-11026, 108, (1981).

External radiation

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 this 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