Sodium Pertechnetate (99mTc) Injection (Non-fission)
This monograph applies to Sodium Pertechnetate (99mTc) Injection obtained from molybdenum-99 produced by
neutron irradiation of molybdenum-98. Sodium Pertechnetate (99mTc) Injection obtained from molybdenum-99
extracted from fission products of uranium is described in the monograph on Sodium Pertechnetate (99mTc) Injection
(Fission).
Category: Diagnostic
Description: A clear, colourless solution suitable for intravenous administration. Sodium Pertechnetate (99mTc)
Injection 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 produced by neutron irradiation of molybdenum.
Technetium-99m has a half-life of 6.02 hour and emits gamma radiation.
Sodium Pertechnetate (99mTc) Injection (Non-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
95 per cent of the radioactivity corresponds to technetium-99m in the form of pertechnetate ion.
Radiopharmaceutical Preparation Sodium Pertechnetate (99mTc) is extracted from aqueous alkaline solution
(5 N NaOH) of Sodium molybdate (Mo99) in distilled methyl ethyl ketone (MEK) using (99mTc) solvent Extraction
Generator. The MEK solution containing Pertechnetate (99mTc) is purified by passing through short column of
alumina and solvent is evaporated by heating. The residual Sodium Pertechnetate (99mTc) is dissolved in 0.9 per cent
w/v sodium chloride aqueous solution and rendered sterile by terminal ultra filtration using 0.22 µ filter or
autoclave.
Identification
A. Determine by gamma-ray spectrometry. The most prominent gamma photon of technetium-99m has energy of
0.140 MeV.
B. Half life of Technetium-99m in test solution should be between 5.7 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). 4.5 to 7.5.
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 radioactivity due to radionuclides other than Technetium-99m, apart from that due to Technetium-99 resulting
from the decay of Technetium-99m is not more than that shown below, expressed as a percentage of the total
radioactivity and calculated with reference to the date and time of administration.
Molybdenum-99 breakthrough not more than 0.1 per cent
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 (1µCi) of
Molybdneum-99m per 37 MBq (1 mCi) of Technetium-99m. . Determination of Molybdenum 99 impurity in test
solution is referred to “Molybdenum Breakthrough Test”.
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 shield is placed in dose calibrator and background activity is measured at Molybdenum99 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 Mo-99 obtained in step (a) is subtracted from Mo-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.
Other gamma-emitting impurities does not exceed 0.01 percent of the total radioactivity
Determine the gamma-ray spectrum of the decayed material for the presence of other radionuclidic impurities,
which should, where possible, be identified and quantified. The total radioactivity due to other radionuclidic
impurities does not exceed 0.01 per cent of the total radioactivity.
Radiochemical purity. Not less than 90 per cent due to Technetium-99m as 99mTc Pertchnetate.
Method A Determine by ascending paper chromatography
Mobile phase. 85 per cent methanol in water
Support Whatman 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 90 min or up to 15 cm and allow to dry in air. Scan the strips using a
radiochromatogram scanner with collimator suitably adjusted to measure 99mTc or cut into one cm sections and
count in a well type NaI(Tl) scintillation counter. 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
Method 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 2 to 5µl of the test solution at 1 cm above the bottom of the strip on Whatman No. 3 paper strip. 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 reduced hydrolysed 99mTc is 0. The chromatographic strip is dried in air and cut into two equal
sections at 3.5cm. The upper half section (section A) and bottom half section (section B) are counted separately in
counting tubes in NaI(Tl) scintillation counter and corrected for background counts. Radiochemical purity is
calculated as under:
% RCP
=
Counts in section A
X 100
Aluminium. By spot test. Apply 10 µl of the test solution by micropipette on spot plate. Drop 30 µl acetate buffer
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).
Molybdenum. By spot test. Take 50 µl of test solution by micropipette on the spot plate. Add 50 µl of 10 per cent
of potassium thiocyanate solution followed by 50 µl of 10 per cent tin(II) chloride solution. The orange red colour
developed should be less intense than that of a standard prepared at the same time and in the same manner using 50
µl of molybdenum standard solution (10ppm ).
Methyl ethyl ketone By spot test: (Only for pertechnetate (99mTc) obtained from solvent extraction method): In a
test tube take 200 µl of 1 M sodium hydroxide solution followed by 200 µl of 0.1M iodine solution. Add 50 µl of
test solution followed by 150 µl of double distilled water. The turbidity in the solution should be less than that of the
turbidity produced by standard methyl ethyl ketone solution (0.1 per cent v/v) prepared at the same time in the
similar manner.
Bacterial endotoxins (2.2.3). Not more than 175/V IU/ml, V being the maximum recommended dose in milliliters.
The test must be completed before release of the preparation.
Sterility 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.
Labelling— The label states, in addition to the information specified under injections (1) the amount of 99mTc as
total megabecquerels (millicuries) and concentration as megabecquerels (millicuries) per ml at the time of
calibration (2) the expiration date (3) the statement “Caution—Radioactive Material.”