Flumazenil C 11 Injection
» Flumazenil C 11 Injection is a sterile solution, suitable for intravenous administration, of Flumazenil in which a portion of the molecules are labeled at the N-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 14.8 GBq (400 mCi) per µmol. It may contain suitable buffers.
Packaging and storage— Preserve in single-dose or 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 [N-methyl-11C]Flumazenil, expressed as MBq (or mCi); the specific activity, expressed as MBq (or mCi) per µmol; the concentration, expressed as MBq (or mCi) 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 8.5.
Radionuclidic purity 821 Using a multichannel analyzer, count all radioactivity from 40 to 2,500 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— Transfer 1.2 g of monobasic sodium phosphate to a 1000-mL volumetric flask, dissolve in 500 mL of deionized distilled water, and dilute with deionized distilled water to volume to obtain a stock solution. Transfer 300 mL of acetonitrile to another 1000-mL volumetric flask, and dilute with the stock solution to volume. Filter and degas. Make adjustments if necessary (see System Suitability under Chromatography 621).
System suitability solution— Dissolve an accurately weighed quantity of USP Flumazenil RS in acetonitrile to obtain a solution having a known concentration of 1 mg of flumazenil 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 flumazenil 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 mL of flumazenil per mL.
Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm × 25-cm column that contains packing L1. The flow rate is about 2 mL per minute. The column temperature is maintained at 20. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the column efficiency is not less than 100 theoretical plates; the tailing factor 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 the Injection taken by the formula:
100(ri / rs)
in which ri is the peak response for each impurity; and rs is the sum of the responses of all the peaks: not more than 0.2% of any individual impurity is found, and not more than 0.9% of total impurities is found.
Radiochemical purity 821
Mobile phase and System suitability 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 responses for the major peaks. The radioactivity under the main peak is not less than 98% of the total radioactivity measured.
Specific activity—
Mobile phase and System suitability solution—Proceed 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— Calculate the specific activity, in MBq (or mCi) per µmol, of Injection by the formula:
3.03(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 flumazenil in the Injection as determined in the test for Chemical purity. The specific activity is not less than 400 mCi per µmol.
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 71, 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 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 1794
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.