(Ph. Eur. monograph 0047)
C6H6N2O 122.1 98-92-0
Action and use
Component of vitamin B.
Preparations
Nicotinamide Tablets
Vitamins B and C Injection
DEFINITION
Pyridine-3-carboxamide.
Content
99.0 per cent to 101.0 per cent (dried substance).
CHARACTERS
Appearance
White or almost white, crystalline powder or colourless crystals.
Solubility
Freely soluble in water and in anhydrous ethanol, slightly soluble in methylene chloride.
IDENTIFICATION
First identification: B.
Second identification: A, C.
A. Melting point (2.2.14): 128 °C to 131 °C.
B. Infrared absorption spectrophotometry (2.2.24).
Comparison: nicotinamide CRS.
C. Thin-layer chromatography (2.2.27).
Test solution: Dissolve 5 mg of the substance to be examined in a mixture of equal volumes of ethanol (96 per cent) R and water R and dilute to 5.0 mL with the same mixture of solvents.
Reference solution: Dissolve 5 mg of nicotinamide CRS in a mixture of equal volumes of ethanol (96 per cent) R and water R and dilute to 5.0 mL with the same mixture of solvents.
Plate: TLC silica gel F254 plate R.
Mobile phase: water R, ethanol (96 per cent) R, methylene chloride R (4:45:48 V/V/V).
Application: 5 μL.
Development: Over 2/3 of the plate.
Drying: In air.
Detection: Examine in ultraviolet light at 254 nm.
Results: The principal spot in the chromatogram obtained with the test solution is similar in position and size to the spot in the chromatogram obtained with the reference solution.
TESTS
Solution S
Dissolve 2.5 g in carbon dioxide-free water R and dilute to 50 mL with the same solvent.
Appearance of solution
Solution S is clear (2.2.1) and not more intensely coloured than reference solution BY7 (2.2.2, Method II).
pH (2.2.3)
6.0 to 7.5 for solution S.
Related substances
Liquid chromatography (2.2.29).
Test solution: Dissolve 0.150 g of the substance to be examined in mobile phase A and dilute to 150.0 mL with mobile phase A.
Reference solution (a): Dilute 1.0 mL of the test solution to 100.0 mL with mobile phase A. Dilute 1.0 mL of this solution to 10.0 mL with mobile phase A.
Reference solution (b): Dissolve 5 mg of isonicotinamide R (impurity D) in the test solution and dilute to 100.0 mL with the test solution. Dilute 1.0 mL of this solution to 25.0 mL with the test solution.
Column:
— size: l = 0.15 m, Ø = 4.6 mm;
— stationary phase: base-deactivated end-capped octadecylsilyl silica gel for chromatography R (3 μm).
Mobile phase:
— mobile phase A: mix 5.0 mL of dilute acetic acid R and 900 mL of water for chromatography R, then add 30 mL of dilute ammonia R3 and 15 mL of acetonitrile R; dilute to 1 L with water for chromatography R;
— mobile phase B: acetonitrile R, mobile phase A (50:50 V/V);
| Time (min) |
Mobile phase A (per cent V/V) |
Mobile phase B (per cent V/V) |
| 0 – 2 | 98 | 2 |
| 2 – 16 | 98 → 0 | 2 → 100 |
Flow rate: 1.0 mL/min.
Detection: Spectrophotometer at 264 nm.
Injection: 20 μL.
Identification of impurities: Use the chromatogram obtained with reference solution (b) to identify the peak due to impurity D.
Relative retention: With reference to nicotinamide (retention time = about 7 min): impurity D = about 0.9.
System suitability: Reference solution (b):
— resolution: minimum 2.0 between the peaks due to impurity D and nicotinamide.
Calculation of percentage contents:
— for each impurity, use the concentration of nicotinamide in reference solution (a).
Limits:
— unspecified impurities: for each impurity, maximum 0.10 per cent;
— total: maximum 0.2 per cent;
— reporting threshold: 0.05 per cent.
Loss on drying (2.2.32)
Maximum 0.5 per cent, determined on 1.000 g by drying in vacuo for 18 h.
Sulfated ash (2.4.14)
Maximum 0.1 per cent, determined on 1.0 g.
ASSAY
Dissolve 0.100 g in 50 mL of anhydrous acetic acid R. Titrate with 0.1 M perchloric acid, determining the end-point potentiometrically (2.2.20).
1 mL of 0.1 M perchloric acid is equivalent to 12.21 mg of C6H6N2O.
IMPURITIES
Other detectable impurities (the following substances would, if present at a sufficient level, be detected by one or other of the tests in the monograph. They are limited by the general acceptance criterion for other/unspecified impurities and/or by the general monograph Substances for pharmaceutical use (2034). It is therefore not necessary to identify these impurities for demonstration of compliance. See also 5.10. Control of impurities in substances for pharmaceutical use) A, B, C, D, E.
A. pyridine-3-carboxylic acid (nicotinic acid),
B. pyridine-3-carbonitrile,
C. pyridine-2-carboxamide (picolinamide),
D. pyridine-4-carboxamide (isonicotinamide),
E. pyridine-3-carboxamide 1-oxide (nicotinamide N-oxide).
