AN-DTPA® Kit for the Preparation of
Technetium Tc 99m Pentetate Injection
Diagnostic For Intravenous Use
AN-DTPA® Kit for the Preparation of Technetium Tc 99m Pentetate Injection is a multidose reaction vial which contains the sterile, non-pyrogenic, non-radioactive ingredients necessary to produce Technetium Tc 99m Pentetate Injection for diagnostic use by intravenous injection.
Each 10 mL reaction vial contains 20.6 mg pentetate calcium trisodium, 0.15 mg minimum stannous tin as stannous chloride dihydrate and 0.30 mg maximum total tin as stannous chloride dihydrate in lyophilized form and sealed under nitrogen. The pH is adjusted to 3.9-4.1 with sodium hydroxide and/or hydrochloric acid prior to lyophilization. No bacteriostatic preservative is present.
The active agent is a Technetium Tc 99m complex of pentetate calcium trisodium. The chemical names and structure for pentetate calcium trisodium are: (1) Calciate (3-), [N,N-bis[2-[bis(carboxymethyl)amino]ethyl]glycinato(5-)]-,trisodium;(2)Trisodium [N,N-bis[2-[bis(carboxymethyl)amino]ethyl]glycinato(5-)]-calciate(3-).
When a solution of sterile, non-pyrogenic, oxidant-free isotonic Sodium Pertechnetate Tc 99m Injection is added to the vial, Technetium Tc 99m Pentetate Injection is formed. The product so derived is intended for intravenous injection within 6 hours of the time of reconstitution. The precise structure of Technetium Tc 99m Pentetate Injection if not known at this time.
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 studies is listed in Table 1.
Table 1. Principal Radiation Emission Data
| Radiation ||
Mean Percent Per
| Mean Energy (keV) |
1Kocher DC: Radioactive decay data tables . DOE/TIC-11026: 108, 1981
The specific gamma ray constant for Tc 99m is 0.78 R/millicurie-hr at 1 cm. The first half-value layer is 0.017 cm of lead (Pb). 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 a 0.25 cm thickness of Pb will attenuate the radiation emitted by a factor of about 1,000.
Table 2. Radiation Attenuation by Lead Shielding
To correct for physical decay of this radionuclide, the fractions that remain at selected intervals after the time of calibration are shown in Table 3.
Table 3. Physical Decay Chart: Tc 99m, half-life 6.02 hours
| Hours ||
| Hours ||