Drugs Similar to CHOLETEC

Each multidose reaction vial contains a nonradioactive, sterile, nonpyrogenic mixture of 45 mg mebrofenin, 0.54 mg (minimum) stannous fluoride dihydrate, SnF 2 •2H 2 O and 1.03 mg total tin, maximum (as stannous fluoride dihydrate, SnF 2 •2H 2 O), not more than 5.2 mg methylparaben, and 0.58 mg propylparaben. The pH is adjusted with sodium hydroxide or hydrochloric acid prior to lyophilization. The contents of the vial are lyophilized and sealed under nitrogen at the time of manufacture. The pH of the reconstituted product is 4.2 to 5.7. The structure of mebrofenin (2,2'-[[2-[(3-Bromo-2,4,6-trimethylphenyl)-amino]-2-oxoethyl]imino] bisacetic acid) is shown below: Molecular Weight = 387.23 When sterile, pyrogen-free sodium pertechnetate Tc 99m injection is added to the vial, the diagnostic agent Technetium Tc 99m Mebrofenin is formed for administration by intravenous injection. 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, David C., "Radioactive Decay Data Tables", DOE/TIC-11026, (1981) p. 108. External Radiation The specific gamma ray constant for Tc 99m is 0.78 R/hour-millicurie 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. 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 technetium Tc 99m, 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 18 0.126 *Calibration time spl-mebrofenin-structure