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Mebrofenin
(me'' broe fen' in).
Glycine, N-[2-[(3-bromo-2,4,6,-trimethylphenyl)amino]-2-oxoethyl]-N-(carboxymethyl)-. [[[(3-Bromomesityl)carbamoyl]methyl]imino]diacetic acid » Mebrofenin contains not less than 97.0 percent and not more than 101.0 percent of C15H19BrN2O5, calculated on the dried basis.
Packaging and storage
Preserve in tight containers. Store at 25
Identification,
Infrared Absorption
Melting range, Class I
Loss on drying
Residue on ignition
Heavy metals, Method II
Limit of nitrilotriacetic acid
Mobile phase
Add 10 mL of a 1 in 4 solution of tetrabutylammonium hydroxide in methanol to 200 mL of water, and adjust with 1 M phosphoric acid to a pH of 7.5 ± 0.1. Transfer this solution to a 1000-mL volumetric flask, add 90 mL of methanol, dilute with water to volume, mix, pass through a filter having a 0.5-µm or finer porosity, and degas. Make adjustments if necessary (see System Suitability under Chromatography
Cupric nitrate solution
Prepare a solution containing about 10 mg of cupric nitrate per mL.
Standard stock solution
Transfer about 25 mg of nitrilotriacetic acid, accurately weighed, to a 50-mL volumetric flask, dilute with dilute ammonium hydroxide (1 in 20) to volume, and mix.
Standard solution
Transfer 10 mL of the Standard stock solution to a 100-mL volumetric flask, and dilute with Cupric nitrate solution to volume. [notePrepare fresh on the day of use. ]
Test solution
Transfer about 250 mg of Mebrofenin, accurately weighed, to a 25-mL volumetric flask, dilute with Cupric nitrate solution to volume, and mix. Sonicate, if necessary, to achieve complete solution. [notePrepare fresh on the day of use. ]
Chromatographic system (see Chromatography
Procedure
Separately inject equal volumes (about 20 µL) of the Standard solution and the Test solution into the chromatograph, and record the chromatograms. Measure the responses for the peaks in each chromatogram at the locus for copper nitrilotriacetic acid. Calculate the quantity, in mg, of nitrilotriacetic acid in the portion of Mebrofenin taken by the formula:
25C(rU / rS)
in which C is the concentration, in mg per mL, of nitrilotriacetic acid in the Standard solution; and rU and rS are the peak responses obtained from the Test solution and the Standard solution, respectively: not more than 0.1% is found.
Chromatographic purity
Mobile phase
Prepare a mixture of equal volumes of 0.025 M monobasic potassium phosphate and 0.025 M dibasic sodium phosphate. To 400 mL of this solution add 600 mL of methanol. Adjust the volume to 1000 mL with water, and adjust with 1 N hydrochloric acid to a pH of 5.0 ± 0.1. Make adjustments if necessary (see System Suitability under Chromatography
Test solution
Transfer about 12.5 mg of Mebrofenin, accurately weighed, to a 25-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography
Procedure
Chromatograph about 20 µL of the Test solution, run the chromatograph for twice the elution time of the mebrofenin peak, and record the peak response for individual impurities and the total response for the entire chromatogram. Calculate the percentage of chromatographic impurities taken by the formula:
100(rs / rt)
in which rs is the sum of the peak responses of the individual impurities; and rt is the total of all of the peak responses in the chromatogram: not more than 3% is found.
Assay
Dissolve about 100 mg of Mebrofenin, accurately weighed, in about 40 mL of dimethylformamide in a conical flask, with the aid of sonication if necessary. Add 3 drops of thymol blue TS, and titrate with 0.1 N sodium methoxide (in toluene) VS to a blue endpoint while flushing the flask with a gentle stream of nitrogen. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N sodium methoxide is equivalent to 19.36 mg of C15H19BrN2O5.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3772
Pharmacopeial Forum: Volume No. 29(6) Page 1923
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