Niacin Tablets
DEFINITION
Niacin Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of niacin (C6H5NO2).
IDENTIFICATION
•  A. Infrared Absorption 197M
Sample: Heat a portion of finely powdered Tablets, equivalent to 500 mg of niacin, with 25 mL of alcohol on a steam bath for a few min. Filter, and wash the residue with a few mL of hot alcohol. To the filtrate add 30 mL of water, and evaporate to 25 mL on the steam bath. Cool, filter if insoluble matter separates, and evaporate the filtrate to 10 mL. Cool, and place in a refrigerator for 1 h. Filter the separated niacin with suction, wash it with a few mL of cold alcohol, and dry at 105 for 1 h.
Acceptance criteria: Meet the requirements
•  B. Ultraviolet Absorption 197U
Medium: 6.8 mg/mL of monobasic potassium phosphate in water, adjusted to a pH of 7.0 with 50% sodium hydroxide solution
Sample solution: 20 µg/mL in Medium from the Sample obtained in the Identification test A
Acceptance criteria: Meets the requirements in the chapter. The A237/A262 ratio is 0.46–0.50.
•  C. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
ASSAY
•  Procedure
Solution A: 5-mM solution of sodium 1-hexanesulfonate in water
Mobile phase: Methanol, acetonitrile, glacial acetic acid, and Solution A (14:7:1:78)
Standard solution: 0.050 mg/mL of USP Niacin RS in water. Dissolve with the aid of heat in a steam bath.
Sample solution: Transfer an equivalent to 500 mg of Niacin from NLT 20 finely powdered Tablets to a suitable flask. Add 50 mL of water, and heat on a steam bath for 30 min. Sonicate for 2 min, shake by mechanical means for 15 min, and cool to room temperature. Dilute with water to 0.050 mg/mL, and filter.
Chromatographic system 
Mode: LC
Detector: UV 262 nm
Column: 4-mm × 30-cm; packing L1
Flow rate: 1.3 mL/min
Injection size: 20 µL
System suitability 
Sample: Standard solution
Suitability requirements 
Column efficiency: NLT 1000 theoretical plates for the analyte peak
Tailing factor: NMT 2.0 for the analyte peak
Relative standard deviation: NMT 2.0%
Analysis 
Samples: Standard solution and Sample solution
Calculate the percentage of the labeled amount of niacin (C6H5NO2) in the portion of Tablets taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak area from the Sample solution
rS== peak area from the Standard solution
CS== concentration of USP Niacin RS in the Standard solution (mg/mL)
CU== nominal concentration of niacin in the Sample solution (mg/mL)
Acceptance criteria: 90.0%–110.0%
PERFORMANCE TESTS
•  Dissolution 711
Medium: 0.1 N hydrochloric acid; 900 mL
Apparatus 1: 100 rpm
Time: 60 min
Standard solution: 0.02 mg/mL of USP Niacin RS in the Medium
Sample solution: Filtered portion of the solution under test, suitably diluted with the Medium if necessary
Instrumental conditions 
Mode: UV
Analytical wavelength: Maximum at about 260 nm
Analysis 
Samples: Standard solution and Sample solution
Determine the concentration of niacin in the Sample solution in comparison with the Standard solution.
Calculate the percentage of the labeled amount of niacin (C6H5NO2) dissolved:
Result = (C × D × V/L) × 100
C== determined concentration of niacin in the Sample solution (mg/mL)
D== dilution factor for the Sample solution
V== volume of Medium, 900 mL
L== label claim (mg/Tablet)
Tolerances: NLT 65% (Q) of the labeled amount of niacin (C6H5NO2) is dissolved.
•  Uniformity of Dosage Units 905: Meet the requirements
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in well-closed containers.
•  USP Reference Standards 11
USP Niacin RS Click to View Structure
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/QuestionContactExpert Committee
MonographNatalia Davydova
Scientific Liaison
1-301-816-8328
(DS2010) Monographs - Dietary Supplements
711Margareth R.C. Marques, Ph.D.
Senior Scientific Liaison
1-301-816-8106
(GCDF2010) General Chapters - Dosage Forms
Reference StandardsRS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 4043
Chromatographic Column— 
Chromatographic columns text is not derived from, and not part of, USP 35 or NF 30.