technetium tc 99m medronate - Medications

Kit for the Preparation of Technetium Tc 99m Medronate is a multidose reaction vial which contains the sterile, non-pyrogenic, non-radioactive ingredients necessary to produce Technetium Tc 99m Medronate Injection for diagnostic use by Intravenous injection. Each 10mL multidose vial contains: Medronic acid: 20 mg Ascorbic acid: 1 mg Stannous fluoride, SnF 2 : 0.13 mg (minimum) Total tin (maximum, as stannous fluoride, SnF 2 ): 0.38 mg The pH is adjusted to 6.5 (6.3 to 6.7) with sodium hydroxide and/or hydrochloric acid prior to lyophilization. No bacteriostatic preservative is present in the vial. The contents of the vial are lyophilized and sealed under nitrogen at the time of manufacture. The structural formula is: When a solution of sterile, non-pyrogenic, oxidant-free Sodium Pertechnetate Tc 99m Injection is added to the vial, the diagnostic agent, Technetium Tc 99m Medronate is formed for administration by intravenous injection. The pH of the reconstituted product is 5.4 to 6.8. The precise structure of Technetium Tc 99m Medronate Injection is not known at this time. Structural Formula 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 studies is listed in Table 1. TABLE 1 Principal Radiation Emission Data Radiation Mean % per Disintegration Mean Energy (keV) Gamma-2 89.07 140.5 1 Kocher, DC: Radioactive Decay Data Tables, DOE/TIC-11026, 108, 1981 . EXTERNAL RADIATION: 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 the various thicknesses of Pb is shown in Table 2. To facilitate control of the radiation exposure from millicurie amounts of this radionuclide, 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 Shield Thickness (Pb) cm Coefficient of Attenuation 0.017 0.5 0.08 10 -1 0.16 10 -2 0.25 10 -3 0.33 10 -4 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 Fraction Remaining Hours Fraction Remaining 0* 1.000 7 0.447 1 0.891 8 0.398 2 0.794 9 0.355 3 0.708 10 0.316 4 0.631 11 0.282 5 0.562 12 0.251 6 0.501 * Calibration Time

Each reaction vial contains a sterile, nonpyrogenic, nonradioactive lyophilized mixture of 20 mg medronic acid, 1 mg ascorbic acid, 0.13 mg (minimum) stannous fluoride, SnF 2 and 0.38 mg total tin, maximum (as stannous fluoride, SnF 2 ). The pH is adjusted with sodium hydroxide or hydrochloric acid to 6.5 (6.3 to 6.7) prior to lyophilization. The vial does not contain a preservative. The contents of the vial are lyophilized and sealed under nitrogen at the time of manufacture. The pH of the reconstituted product is 5.4 to 6.8. The structure of medronic acid is given below: The precise structure of technetium Tc 99m medronate is unknown at this time. When sterile, pyrogen-free sodium pertechnetate Tc 99m injection is added to the vial, the diagnostic agent technetium Tc 99m medronate is formed for administration by intravenous injection. Structure of Medronic Acid