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Niacin
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C6H5NO2 123.11

3-Pyridinecarboxylic acid.
Nicotinic acid [59-67-6].
» Niacin contains not less than 99.0 percent and not more than 101.0 percent of C6H5NO2, calculated on the dried basis.
Packaging and storage— Preserve in well-closed containers.
Identification—
B: Ultraviolet Absorption 197U—
Solution: 20 µg per mL.
Medium: Use the Buffer solution, prepared as directed in the Assay.
Ratio: A237 / A262, between 0.46 and 0.50.
Loss on drying 731— Dry it at 105 for 1 hour: it loses not more than 1.0% of its weight.
Residue on ignition 281: not more than 0.1%.
Chloride 221— A 0.50-g portion shows no more chloride than corresponds to 0.15 mL of 0.020 N hydrochloric acid (0.02%).
Sulfate 221— A 0.50-g portion shows no more sulfate than corresponds to 0.10 mL of 0.020 N sulfuric acid (0.02%).
Heavy metals, Method I 231— Mix 1 g with 4 mL of 1 N acetic acid, dilute with water to 25 mL, heat gently until solution is complete, and cool: the limit is 0.002%.
Ordinary impurities 466—
Test solution: water.
Standard solution: water.
Eluant: a mixture of methanol and 0.1 N hydrochloric acid (9:1).
Visualization: 1.
Organic volatile impurities, Method IV 467: meets the requirements.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay—
Buffer solution— Dissolve 6.8 g of monobasic potassium phosphate in 1 L of water. Adjust with 50% sodium hydroxide solution to a pH of 7.0.
Assay preparation— Transfer about 200 mg of Niacin, accurately weighed, to a 500-mL volumetric flask; add the Buffer solution to dissolve; dilute with the Buffer solution to volume; and mix. Transfer 5.0 mL of this solution to a 100-mL volumetric flask, dilute with the Buffer solution to volume, and mix.
Procedure— Concomitantly determine the absorbances of the Assay preparation and a solution of USP Niacin RS in the same medium (Standard preparation), at a concentration of about 20 µg per mL, in 1-cm cells at the wavelength of maximum absorbance at about 262 nm, with a suitable spectrophotometer, using the Buffer solution as the blank. Calculate the quantity, in mg, of C6H5NO2 in the portion of Niacin taken by the formula:
10C(AU / AS),
in which C is the concentration, in µg per mL, of USP Niacin RS in the Standard preparation; and AU and AS are the absorbances of the solution of the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Staff Liaison : Lawrence Evans, III, Ph.D., Scientist
Expert Committee : (DSN05) Dietary Supplements - Non-Botanicals
USP29–NF24 Page 1520
Pharmacopeial Forum : Volume No. 29(6) Page 1937
Phone Number : 1-301-816-8389