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1 TechneScan MAAP ackage inserts are current as of January, 1997. Contact Professional Services,1-888-744-1414, regarding possible here to ContinueClick here to Return to Table of ContentsTechneScan MAA 093 Kit for the Preparation of Technetium Tc 99m Albumin Aggregated A093I0R7/95 Diagnostic For Intravenous UseDESCRIPTIONThe kit consists of five or thirty multidose reaction vials which contain the sterile, non-pyrogenic, non-radioactive ingredients necessary to produce Technetium Tc 99 Albumin Aggregated Injection fordiagnostic use by intravenous 10-milliliter reaction vial contains 2 milligrams of aggregated albumin human, milligram ofalbumin human, 120 micrograms of stannous chloride (SnCl2 2H2O), 80 milligrams of lactose, 24milligrams of succinic acid and milligrams of sodium acetate in lyophilized form under an atmosphereof nitrogen.

2 Hydrochloric acid or sodium hydroxide has been added for pH adjustment. No bacteriostaticpreservative is MAA is prepared from albumin that was non-reactive when tested for hepatitis B antigen(HBsAg) by radioimmunoassay. Each vial contains approximately 8 4 x 106 aggregated albuminparticles. The particle size distribution of the aggregated albumin is such that not less than 90 percent are10 to 90 microns in size. Typically, approximately 90 percent are within the 10 to 40 micron are no aggregated albumin particles greater than 150 microns in Tc 99m Albumin Aggregated Injection for intravenous use is in its final dosage form whensterile isotonic sodium pertechnetate Tc-99m solution is added to each vial.

3 No less than 90% of thepertechnetate Tc-99m added to the reaction vial is bound to the aggregates at preparation time andremains bound throughout the 8-hour lifetime of the precise structure of the stannous-technetium-albumin complex is unknown at this CHARACTERISTICST echnetium-99m decays by isomeric transition with a physical half-life of The principalphoton that is useful for detection and imaging is listed in Table 1 Table 1. Principal Radiation Emission Data 1 RadiationMean % perDisintegrationEnergy (keV) RADIATIONThe specific gamma ray constant for technetium 99m is R/mCi-hr at 1 cm.

4 The first half-valuethickness of lead (Pb) for technetium 99m is cm. A range of values for the relative attenuation of theradiation emitted by this radionuclide that results from interposition of various thicknesses of Pb is shownin Table 2. For example, the use of cm of Pb will decrease the external radiation exposure by a factorof about 2. Radiation Attenuation by Lead ShieldingShieldThickness (Pb) cmCoefficient correct for physical decay of this radionuclide, the fractions that remain at selected time intervals afterthe time of calibration are shown in Table 3. Physical Decay Chart: Technetium-99m Half-Life HoursHoursFractionRemainingHoursFraction Remaining0* *Calibration TimeCLINICAL PHARMACOLOGYW ithin 1 to 5 minutes of intravenous injection, over 90 percent of the technetium 99m albuminaggregated particles are trapped in the arterioles and capillaries of the selectivity is a direct result of particle size.

5 Below 1 to 10 microns, the albumin aggregates aretaken up by the reticuloendothelial system. Above 10 to 15 microns, the aggregates become lodged in thelung capillaries by a purely mechanical process. Distribution of aggregated albumin in the lungs is afunction of regional pulmonary blood albumin aggregated is sufficiently fragile for the capillary microocclusion to be temporary. Erosionand fragmentation reduce the particle size, allowing passage of the aggregates through the pulmonaryalveolar capillary bed. The fragments are then accumulated by the reticuloendothelial animal tissue distribution studies, measurements of retained activity showed a lung to liver ratio ofabout 70:1 within the first thirty minutes.

6 Elimination of the technetium-99m albumin aggregated fromthe lungs occurs with a biological half-life of about hours. Cumulative urinary excretion studies showan average of about 75% elimination of the injected technetium-99m dose 24 hours post of the technetium 99m albumin aggregates from the normal and abnormal human lungsoccurs with a biological half-life of hours. The effective half-life was estimated to be hours forthe administration of technetium Tc 99m albumin aggregated by intraperitoneal injection, theradiopharmaceutical mixes with the peritoneal fluid. Clearance from the peritoneal cavity varies frominsignificant, which may occur with complete shunt blockage, to very rapid clearance with subsequenttransfer into the systemic circulation when the shunt is images should be obtained of both the shunt and lung (target organ).

7 However, an adequateevaluation of the difference between total blockage of the shunt and partial blockage may not be feasible inall data are available on AND USAGET echneScan MAA Tc 99m is indicated for scintigraphic imaging of the lungs as an adjunct to otherdiagnostic procedures whenever information about pulmonary circulation is Tc 99m albumin aggregated also may be used in adults as an imaging agent to aid in theevaluation of peritoneo-venous (LeVeen) shunt MAA Tc 99m should not be administered to patients with severe pulmonary use of TechneScan MAA Tc 99m is contraindicated in persons with a history of hypersensitivityreactions to products containing human serum possibility of allergic reactions should be considered in patients who receive multiple doses ofTechneScan MAA Tc , the intravenous administration of particulate material such as aggregated albumin imposesa temporary small mechanical impediment to blood flow.

8 While this effect is probably physiologicallyinsignificant in most patients, the administration of aggregated albumin is possibly hazardous in acute corpulmonale and other states of severely impaired pulmonary blood cases of right-to-left cardiac shunt, additional risk may exist due to the rapid entry of aggregatedalbumin particles into the systemic contents of the TechneScan MAA reaction vial are not radioactive. However, after the sodiumpertechnetate Tc 99m is added, adequate shielding of the final preparation must be labeling reactions involved in preparing TechneScan MAA Tc 99m depend upon maintaining tin inthe reduced state.

9 Any oxidants present in the sodium pertechnetate Tc 99m may thus adversely affect thequality of the preparation. Hence, sodium pertechnetate Tc-99m containing oxidizing agents are notsuitable for preparation of TechneScan MAA Tc contents of the TechneScan MAA reaction vial are sterile and nonpyrogenic. It is essential that theuser follow the directions carefully and adhere to strict aseptic procedures during preparation of of the reaction vial are intended only for use in the preparation of Technetium Tc 99m AlbuminAggregated Injection and are not to be administered directly to the MAA Tc 99m is a suspension and as such the particles will settle with time.

10 Failure to mixthe reaction vial contents adequately before use may result in a non-homogenous suspension with aresulting non-uniform distribution of radioactivity in the lung. If a dose is not administered immediatelyupon removal from the vial, the syringe should be agitated just prior to injection. A small air space in thesyringe is needed to effect is also recommended that, because of the increasing probability of agglomeration with aging,TechneScan MAA Tc 99m not be used after eight hours from the time of reconstitution. If blood iswithdrawn into the syringe any unnecessary delay prior to injection may result in clot formation in contents of the reaction vial are under a nitrogen atmosphere and should be protected from air.