Specific activity—
Mobile phase
and
Standard solution—Prepare as directed in the test for
Chemical purity.
Chromatographic system—
Proceed as directed in the test for Chemical purity.
Procedure—
Calculate the specific activity, in MBq (or mCi) per µmol, of Mespiperone C 11 Injection by the formula:
3.11(Cr Pr) / C,
in which
Cr is the radioactivity content, in MBq (or mCi) per mL, as determined in the
Assay for radioactivity,
Pr is the radiochemical purity (in %), as determined in the test for
Radiochemical purity, and
C is the concentration (in µg per mL) of 3-methylspiperone in the Injection, as determined in the test for
Chemical purity.
Packaging and storage—
Preserve in single-dose or in multiple-dose containers that are adequately shielded.
Labeling—
Label it to include the following: the time and date of calibration; the amount of 11C as methylspiperone expressed as total GBq (or mCi) at time of calibration; the expiration time and date; the lot or batch number; and the statements, “Caution—Radioactive Material” and “Do not use if cloudy or if it contains particulate matter.” The labeling indicates that in making dosage calculations correction is to be made for radioactive decay, and states that the radioactive half-life of 11C is 20 minutes.
Radionuclide identification (see Radioactivity 
821
)—
Its gamma- ray spectrum is identical to that of a specimen of
11C in that it exhibits a positron annihilation peak at 0.511 MeV and possibly a sum peak of 1.022 MeV, dependent on geometry and detector efficiency.
Bacterial endotoxins 85—
It contains not more than 175/
V USP Endotoxin Unit per mL of the Injection, in which
V is the maximum recommended total dose, in mL, at the expiration time.
Radionuclidic purity 821—
Using a multichannel analyzer, count all radioactivity from 40 to 2500 KeV to determine the absence of radiation, other than at 0.511 MeV and 1.022 MeV, over a period of 4 hours. Determine the half-life (20 minutes) by a suitable detector system.
Chemical purity—
Mobile phase—
Prepare a filtered and degassed mixture of acetonitrile and 0.05
M monobasic potassium phosphate (70:30). Make adjustments if necessary (see
System Suitability under
Chromatography 621).
Standard solution—
Dissolve an accurately weighed quantity of 3-methylspiperone hydrochloride in Mobile phase, and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 0.1 mg per mL.
Test solution—
Pipet an accurately measured volume of Injection into a suitable container, and dilute with Mobile phase to obtain a solution containing about 0.1 mg per mL.
Chromatographic system
(see
Chromatography 621). The liquid chromatograph is equipped with a 254-nm detector and a 3.9-mm × 30-cm column that contains packing L1. The flow rate is about 0.8 mL per minute. For simultaneous analysis of radiochemical purity, a suitable radioactivity detector (see
Radioactivity 821) is coupled to the system. Chromatograph the
Standard solution, and record the peak responses as directed for
Procedure: the column efficiency determined from the analyte peak is not less than 100 theoretical plates, the tailing factor for the analyte peak is not more than 1.1, and the relative standard deviation for replicate injections is not more than 3.2%.
Procedure—
Inject about 20 µL of the
Test Solution into the chromatograph, record the chromatogram, and measure the peak responses. Separately calculate the percentage of each impurity in the portion of Injection taken by the formula:
100(ri / rs),
in which
ri is the peak response obtained for each impurity, and
rs is the sum of the responses of all of the peaks: not more than 0.2% of any individual impurity is found, and the sum of all impurities is not more than 0.9%.
Radiochemical purity 821—
Proceed as directed in the test for
Chemical purity, except that the liquid chromatograph is also equipped with a suitable collimated radioactivity detector. The radioactivity under the main peak is not less than 98% of the total radioactivity measured.
Other requirements—
It meets the requirements under
Injections 1, except that the Injection may be distributed or dispensed prior to completion of the test for
Sterility, the latter test being started on the day following final manufacture, and except that it is not subject to the recommendation on
Volume in Container.
Assay for radioactivity 821—
Using a suitable counting assembly (see
Selection of a Counting Assembly), determine the radioactivity, in GBq (or mCi) per mL, of Injection by use of a calibrated system.
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