Riboflavin
» Riboflavin contains not less than 98.0 percent and not more than 102.0 percent of C17H20N4O6, calculated on the dried basis.
Packaging and storage
Preserve in tight, light-resistant containers.
Identification
A solution of 1 mg in 100 mL of water is pale greenish yellow by transmitted light, and has an intense yellowish-green fluorescence that disappears upon the addition of mineral acids or alkalies.
Specific rotation
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Test solution:
5 mg per mL, in 0.05 M sodium hydroxide free from carbonate. Measure the specific rotation within 30 minutes of preparation.
Loss on drying
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Residue on ignition
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Limit of lumiflavin
Prepare alcohol-free chloroform just prior to use, as follows. Shake 20 mL of chloroform gently but thoroughly with 20 mL of water for 3 minutes, draw off the chloroform layer, and wash twice more with 20-mL portions of water. Finally, filter the chloroform through a dry filter paper, shake it for 5 minutes with 5 g of powdered anhydrous sodium sulfate, allow the mixture to stand for 2 hours, and decant or filter the clear chloroform. Shake 25 mg of Riboflavin with 10 mL of the alcohol-free chloroform for 5 minutes, and filter: the absorbance of the filtrate, determined in 1-cm cells at a wavelength of 440 nm, with a suitable spectrophotometer, alcohol-free chloroform being used as the blank, does not exceed 0.025.
Assay
[noteConduct the entire procedure without exposure to direct sunlight.] Place about 50 mg of Riboflavin, accurately weighed, in a 1000-mL volumetric flask containing about 50 mL of water. Add 5 mL of 6 N acetic acid and sufficient water to make about 800 mL. Heat on a steam bath, protected from light, with frequent agitation until dissolved. Cool to about 25
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C(IU / IS)
in which C is the concentration, in µg per mL, of USP Riboflavin RS in the final solution of the Standard, and IU and IS are the corrected fluorescence values observed for the solutions of the Riboflavin and Standard, respectively.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
Chromatographic Column
USP32NF27 Page 3497
Pharmacopeial Forum: Volume No. 30(3) Page 929
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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