technetium tc 99m mertiatide - Medication Listings

11.1 Chemical Characteristics Kit for the Preparation of Technetium Tc 99m Mertiatide Injection is a sterile, multiple-dose kit for the preparation of technetium Tc 99m mertiatide injection, a radioactive diagnostic agent for intravenous use. The active ingredient, betiatide, is N-[N-[N-[(benzoylthio) acetyl]glycyl]glycyl]-glycine and has a molecular weight of 367.38 g/mol. After reconstitution with sodium pertechnetate Tc 99m injection, the radioactive agent technetium Tc 99m mertiatide (disodium[N-[N-[N- (mercaptoacetyl) glycyl]glycyl] glycinato (2-) - N,N′,N″,S′]oxotechnetate (2-)) is formed in situ. Each 10 mL vial contains 1 mg betiatide, 20 mg lactose monohydrate, 40 mg sodium tartrate dihydrate, 0.07 mg (minimum) stannous chloride dihydrate and 0.2 mg (maximum) total tin expressed as stannous chloride dihydrate. Prior to lyophilization, hydrochloric acid is added for pH adjustment. The vial contents are sealed under argon. After radiolabeling with sodium pertechnetate Tc 99m injection, each vial contains up to 3,700 MBq (100 mCi) of technetium Tc 99m mertiatide in 0.9% sodium chloride injection in approximately 10 mL volume as a sterile, clear, and colorless solution with a pH between 5 and 6. betiatide-chem-stuct tc-99m-mertiatide 11.2 Physical Characteristics Technetium Tc 99m decays by isomeric transition with a physical half-life of 6.02 hours. The principal photon that is useful for detection and imaging is listed in Table 2. Table 2. Principal Radiation Emission Data Radiation M Mean % per Disintegration Energy (keV) Gamma-2 89.07 140.5 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 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 11.3 External Radiation The specific gamma ray constant for technetium-99m is 0.78 R/mCi-hr at 1 cm. The first half-value thickness of lead (Pb) for technetium-99m is 0.017 cm. The use of 0.25 cm of Pb, for example, will decrease the external radiation exposure by a factor of about 1,000. Table 4 displays the radiation attenuation by lead shielding. Table 4. 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