Sodium Pertechnetate (99mTc) Injection (Fission)
Category. Diagnostic.
Description. A clear, colourless solution.
Sodium Pertechnetate (99mTc) Injection (Fission) is a sterile solution containing technetium-99m in the form of
pertechnetate ion and made isotonic by the addition of sodium chloride. Technetium-99m is a radionuclide formed
by the decay of molybdenum-99. Molybdenum-99 is a radioactive isotope of molybdenum extracted from uranium
fission products.
Sodium Pertechnetate (99mTc) Injection (Fission) contains not less than 90.0 per cent and not more than 110.0 per
cent of the stated technetium-99m radioactivity at the date and time stated on the label. Not less than 90 per cent of
the radioactivity corresponds to technetium-99m in the form of pertechnetate ion. Technetium-99m has a half-life of
6.02 hours and emits gamma radiation.
Radiopharmaceutical Preparation Sodium Pertechnetate (99mTc) is extracted from Technetium-99m column
chromatography generator containing fission-produced Molybdenum-99 adsorbed on acidic alumina column. Saline
(0.9 per cent sodium chloride solution) is used to elute Sodium Pertechnetate (99mTc) solution which is sterlised by
ultrafiltartion through 0.22 µ filter.
Identification
A. Determine by gamma-ray spectrometry. The gamma-ray spectrum obtained from an aliquot test solution
corresponds to the spectrum obtained with reference solution of Technetium-99m either by direct comparison or by
using an instrument calibrated with the aid of such a solution. The most prominent gamma photon of technetium99m has energy of 0.140 MeV.
B. Half life of Technetium-99m in test solution is determined by measurement of radioactivity in an aliquot of test
solution at three different time intervals using calibrated radioactivity dose calibrator or radioactivity counter. It
should be between 5.7 hours to 6.3 hours.
C. In the test for Radiochemical purity, the chromatogram obtained contributes to the identification of the
distribution of radioactivity in the preparation.
Tests
pH (2.4.24). 4.0 to 8.0.
Radioactivity Assay. Radioactivity of an aliquot of Test Solution is assayed using precalibrated radioactivity dose
calibrator as described in measurement of radioactivity. It is expressed as MBq(mCi) in volume V ml at a particular
time and date.
Radionuclidic purity. Not less than 99.9 per cent due to Technetium-99m.
The fission 99Mo to be used for extraction of Technetium-99m (fission) shall meet specification with respect to the
following fission products:
However 99m Tc or Fission 99Mo need not be re-analysed for radionuclide impurity for the fission products, if
fission 99Mo to be used for the extraction of 99mTc is procured from reputed manufacturers or suppliers who
certifies the specification on radionuclide purity of fission 99Mo for the following radionuclide.
Radionuclide
iodine-131
ruthenium-103
strontium-89
strontium-90
alpha-emitting impurities
other gamma-emitting impurities
Limit (not more than)
5 × 10−3 per cent
5 × 10−3 per cent
6 × 10−5 per cent
6 × 10−6 per cent
1 × 10−7 per cent
0.01 per cent
Molybdenum-99, Iodine-131, Ruthenium-103, Strontium-89, yttrium-90 and other gamma-emitting impurities shall
not more than 0.1 per cent of total radioactivity).
Molybdenum-99. Molybdenum-99 is principal radionuclidic impurity which is required to be determined in test
solution. The prescribed Molybdenum-99 impurity in test solution should not exceed 37 KBq (1 µCi) of
Molybdneum-99m per 37 MBq (1 mCi) of Technetium-99m. The radionuclidic purity of Technetium-99m in test
solution should not be less than 99.9 per cent. Determination of Molybdenum-99 impurity in test solution is referred
to “Molybdenum-99 Breakthrough Test”. This test can be done by two methods:
Method A. By using 4-6 mm thick lead radiation shield and calibrated dose calibrator for assaying Molybdenum-99
activity in test solution.
a) Empty 4-6 mm thick lead radiation shield is placed in dose calibrator and background activity is measured at
Molybdenum-99 setting of the dose calibrator.
b) Pertechnetate (99mTc) test solution vial is placed in Molybdenum-99 assay shield and Molybdenum-99 activity is
measured in dose calibrator at the calibration factor for Molybdenum-99
c) The background activity for Molybdenum-99 obtained in step (a) is subtracted from Molybdenum-99 activity
reading in Step (b). The correction factor for Molybdenum-99 gamma photon attenuation by lead shield is taken as
recommended for the dose calibrator to determine Molybdenum-99 radioactivity.
d) The Technetium-99m test solution vial is removed from the Molybdenum-99 assay shield container and assayed
for Technetium-99m radioactivity in dose calibrator at setting for Technetium-99m.
e) Molybdenum-99 activity (in KBq) divided by Technetium-99m activity (MBq) gives Molybdenum-99
Breakthrough in KBq/MBq Tc 99m.
Method B. Molybdenum-99 breakthrough in Technetium-99m test solution can also be determined by Gamma ray
spectrometry by the following procedure.
The activity (s µCi), of 0.3 ml of the Sodium Pertechnetate ( 99mTc) test solution is measured in a pre-calibrated dose
calibrator. Similarly the activity (r µCi) of 0.3 ml of the Molybdenum-99 sodium molybdate (reference standard)
solution is measured. This Molybdenum-99 reference standard, taken in a lead pot pf 4-7 mm lead thickness and its
count rate determined in a scintillation counter, set to 700-800 keV range, at a reproducible distance from the
detector (q cpm). In the same manner the count rates of the test Sodium Pertechnetate 99mTc (s µCi) test solution is
determined in the same range and at the same distance (p cpm). The count rates are corrected for background and
the percentage of Molybdenum-99 content in Sodium Pertechnetate (99mTc), calculated by the expression,
(100rp)/(qs), where p = net count rate of Molybdenum-99 radionuclidic impurity in 0.3 ml the Sodium
Pertechnetate (99mTc) test solution, q= net count rate of the Molybdenum-99 sodium molybdate solution (0.3ml).
Retain a sample of the injection for a sufficient time to allow the technetium-99m radioactivity to decay to a
sufficiently low level to permit the detection of radionuclidic impurities. All measurements of radioactivity are
expressed with reference to the date and time of administration.
Iodine-131. By gamma ray spectrometry.The most prominent photon has an energy of 0.364 MeV. Iodine-131 has a
half-life of 8.08 days. Not more than 5 × 10−3 per cent of the total radioactivity is due to iodine-131.
Ruthenium-103. By gamma ray spectrometry. The most prominent photon has an energy of 0.497 MeV. Ruthenium103 has a half-life of 39.3 days. Not more than 5 × 10−3 per cent of the total radioactivity is due to ruthenium-103.
Strontium-89. By beta ray counter. Determine the presence of strontium-89 in the injection by a counting system
appropriate for the detection of particulate radiations. Strontium-89 decays with a beta emission of 1.463 MeV
maximum energy and has a half-life of 52.7 days. Not more than 6 × 10−5 per cent of the total radioactivity is due to
strontium-89.
Strontium-90. By beta ray counter. Determine the presence of strontium-90 in the injection by a counting system
appropriate for the detection of particulate radiations. Strontium-90 decay with beta emissions of 0.546 MeV
maximum energy and half-lives of 27.7 years and 64.0 hours. Not more than 6 × 10−6 per cent of the total
radioactivity is due to strontium-90.
Other gamma-emitting impurities. The total gamma radioactivity due to these impurities is not more than 0.01 per
cent of the total radioactivity. Not more than 0.001 Bq of gross alpha impurity per 1 MBq of technetium-99m is
present at the time of administration.
Alpha-emitting impurities. Determine the alpha radioactivity of the decayed material to detect any alpha-emitting
radionuclidic impurities, which should, where possible, be identified and quantified. The total alpha radioactivity
due to these impurities is not more than 1 × 10−7 per cent of the total radioactivity.
Radiochemical purity. Not less than 90 per cent due to Technetium-99m as 99mTc Pertchnetate.
A) Determine by ascending paper chromatography (2.4.15).
Mobile phase. A mixture of 15 volumes of water and 85 volumes of methanol.
Support: Whatman Chromatography paper No 1
Test solution. Dilute the injection under examination with water or saline (0.9 per cent sodium chloride w/v
solution) to a suitable radioactive concentration.
Apply 5 µl of the test solution. Develop for 2 hour and allow to dry in air. Determine the distribution of radioactivity
using a suitable detector. Not less than 90 per cent of the total radioactivity is found in the spot corresponding to
pertechnetate ion, which has an RF value of about 0.5 to 0.7.
B) Determine by rapid paper chromatography (...).
Mobile phase. Acetone or methyl ethyl ketone.
Test solution. Dilute the injection under examination with water or saline (0.9 per cent sodium chloride w/v
solution) to a suitable radioactive concentration.
Apply 2µl of the test solution at 1 cm above the bottom of the strip on Whatman No. 3MM paper strip (0.5 x 7 cm).
Run the chromatogram in acetone or methyl ethyl ketone upto a distance of 6 cm. The Rf value for 99mTc
Pertchnetate is 1 and Rf value for radiochemical purity (reduced hydrolysed 99mTc) is 0.
Paper chromatography strip is cut in two equal sections. Radioactivity in each section is measured using gamma
scintillation counter and radiochemical purity is calculated as described in general chapter on Radiopharmaceuticals.
Aluminium. By spot test. Apply 10 µl of the test solution by micropipette on spot plate. Drop 30 µl acetate buffer
solution pH 4.6. Add 10 µl of a 1.0 per cent w/v solution of chromazurol S. After 3 minutes, red or pink colour of
the solution is not more intense than that of a standard prepared at the same time and in the same manner using 10
µl of aluminium standard solution (10ppm).
Sterility (2.2.11). Complies with the test for sterility as described in general chapter on Radiopharmaceutical
preparation. The injection may be released for use before completion of the test.
Bacterial endotoxins (2.2.3). Not more than 175/V IU/ml, V being the maximum recommended dose in milliliters.