Raclopride C 11 Injection
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» Raclopride C 11 Injection is a sterile solution, suitable for intravenous administration, of raclopride, in which a portion of the molecules are labeled at the O-methyl position with radioactive 11C. It contains not less than 90.0 percent and not more than 110 percent of the labeled amount of 11C expressed in MBq (or mCi) at the time indicated in the labeling. Its specific activity is not less than 18.5 Gbq (500 mCi) per µmol. It may contain suitable buffers.
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 Radiochemical purity.
Procedure— Calculate the specific activity, in GBq (or mCi) per µmol, of Injection by the formula:
3.47(CrPr) / 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 raclopride 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, in addition to the information specified for Labeling under Injections 1: the time and date of calibration; the amount of 11C as [O-methyl-11C]raclopride, expressed as total megabecquerels (or millicuries); the specific activity, expressed as megabecquerels (or millicuries) per µmol; and the concentration, expressed as megabecquerels (or millicuries) per mL, at the date and time of calibration; the expiration date and time; the lot or batch number; the name and quantity of any added preservative or stabilizer; 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 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 upon geometry and detector efficiency.
Bacterial endotoxins 85 It contains not more than 175/V USP Endotoxin Unit per mL, in which V is the maximum recommended total dose, in mL, at the expiration date or time.
pH 791: between 4.5 and 7.
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— Add 840 µL of phosphoric acid to 500 mL of deionized distilled water in a 1000-mL volumetric flask. Add 270 mL of acetonitrile, dilute with deionized distilled water to volume, filter, and degas. Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution— Dissolve an accurately weighed quantity of raclopride (as the tartrate salt) in water to obtain a solution having a known concentration of about 1 mg of raclopride per mL. Dilute a portion of this solution quantitatively with Mobile phase to obtain a solution having a known concentration of about 10 µg of raclopride per mL.
Test solution— Prepare a solution by quantitatively diluting an accurately measured volume of Injection, equivalent to about 37 MBq (1 mCi) of radioactivity, with 10 parts of Mobile phase, and mix.
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 L9. The flow rate is about 2 mL per minute. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.75 for O-desmethylraclopride and 1.0 for raclopride; the resolution, R, between acetate and carbonate is not less than 1.5; the column efficiency determined from the analyte peak is not less than 85 theoretical plates; and the relative standard deviation for replicate injections is not more than 10.0%.
Procedure— Separately inject equal volumes (about 20 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the areas of the responses for the raclopride peaks. Calculate the concentration, in µg per mL, of raclopride (C15H20Cl2N2O3) in the portion of Injection taken by the formula:
C(rU / rS)
in which C is the concentration, in µg per mL, of raclopride in the Standard solution; and rU and rS are the raclopride peak responses obtained from the Test solution and the Standard solution, respectively. In the chromatogram of the Test solution, the area of the peak with a retention time of about 6 minutes (raclopride) is not less than 98% of the total area of all peaks.
Radiochemical purity—
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, except that the liquid chromatograph is also equipped with a suitable collimated radiation detector (see Radioactivity 821).
Procedure— Inject about 20 µL of the Injection into the chromatograph, record the chromatogram, and measure the areas of the responses for the major peaks. The radioactivity under the main peak is not less than 95% of the total area of all peaks observed, and its retention time is within 10% of that obtained for the Standard solution, similarly chromatographed.
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 under Radioactivity 821), determine the radioactivity, in MBq (or mCi) per mL, of Injection by use of a calibrated system.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ian DeVeau, Ph.D.
Director, Veterinary Drugs and Radiopharmaceuticals
1-301-816-8178
(RMI05) Radiopharmaceuticals and Medical Imaging Agents 05
Reference Standards Lili Wang, Technical Services Scientist
1-301-816-8129
RSTech@usp.org
85 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
1-301-816-8339
(MSA05) Microbiology and Sterility Assurance
USP32–NF27 Page 1796