Nitrofurazone

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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C₆H₆N₄O₄ 198.14

Hydrazinecarboxamide, 2-[(5-nitro-2-furanyl)methylene]-;

5-Nitro-2-furaldehyde semicarbazone  CAS RN®: 59-87-0;UNII: X8XI70B5Z6.

1 DEFINITION

Nitrofurazone contains NLT 98.0% and NMT 102.0% of nitrofurazone (C₆H₆N₄O₄), calculated on the dried basis.

[Note-Avoid at all times exposing solutions of nitrofurazone to direct sunlight, excessive heat, strong fluorescent lighting, and alkaline materials.]

2 IDENTIFICATION

Change to read:

2.1 A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K

Change to read:

2.2 B. Spectroscopic Identification Tests 〈197〉, Ultraviolet-Visible Spectroscopy: 197U

Sample solution: 8 µg/mL, prepared as directed in the Assay

Acceptance criteria: The ratio A₃₀₆ / A₃₇₅ is NMT 0.25.

3 ASSAY

3.1 Procedure

Standard stock solution: 0.4 mg/mL of USP Nitrofurazone RS prepared as follows. Transfer 100 mg of USP Nitrofurazone RS to a 250-mL volumetric flask. Dissolve in 50 mL of dimethylformamide, and dilute with water to volume.

Standard solution: 8 µg/mL of USP Nitrofurazone RS in water from Standard stock solution

Sample stock solution: 0.4 mg/mL of Nitrofurazone prepared as follows. Transfer 100 mg of Nitrofurazone to a 250-mL volumetric flask. Dissolve in 50 mL of dimethylformamide, and dilute with water to volume.

Sample solution: 8 µg/mL of Nitrofurazone in water from Sample stock solution

Instrumental conditions

• Mode: UV-Vis
• Analytical wavelength: 375 nm
• Cell: 1 cm
• Blank: Water

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of nitrofurazone (C₆H₆N₄O₄) in the portion of Nitrofurazone taken:

Result = (Aᵤ/Aₛ) × (Cₛ/Cᵤ) × 100

Aᵤ = absorbance of the Sample solution

Aₛ = absorbance of the Standard solution

Cₛ = concentration of USP Nitrofurazone RS in the Standard solution (µg/mL)

Cᵤ = concentration of Nitrofurazone in the Sample solution (µg/mL)

Acceptance criteria: 98.0%–102.0% on the dried basis

4 IMPURITIES

4.1 Residue on Ignition 〈281〉: NMT 0.1%

4.2 Organic Impurities

Mobile phase: Acetonitrile and water (40:60)

Peak identification solution: 0.1 mg/mL each of USP Nitrofurazone Related Compound A RS and USP Nitrofurfural Diacetate RS in Mobile phase

System suitability solution: 0.1 mg/mL each of USP Nitrofurazone RS and USP Nitrofurantoin RS in Mobile phase

Standard solution: 5 µg/mL of USP Nitrofurazone RS in Mobile phase

Sample solution: 1 mg/mL of Nitrofurazone in Mobile phase

Chromatographic system

• (See Chromatography 〈621〉, System Suitability.)
• Mode: LC
• Detector: UV 310 nm
• Column: 4.6-mm × 25-cm; 5-µm packing L1
• Flow rate: 1 mL/min
• Injection volume: 20 µL
• Run time: NLT 10 times the retention time of nitrofurazone

System suitability

• Samples: System suitability solution and Standard solution
• [Note-The relative retention times for nitrofurazone and nitrofurantoin are about 1.0 and 1.1, respectively.]
• Suitability requirements
• Resolution: NLT 2.0 between nitrofurazone and nitrofurantoin, System suitability solution
• Relative standard deviation: NMT 2.0%, Standard solution

Analysis

Samples: Peak identification solution, Standard solution, and Sample solution

Calculate the percentage of each impurity in the portion of Nitrofurazone taken:

Result = (rᵤ/rₛ) × (Cₛ/Cᵤ) × (1/F) × 100

rᵤ = peak response of each impurity from the Sample solution

rₛ = peak response of nitrofurazone from the Standard solution

Cₛ = concentration of USP Nitrofurazone RS in the Standard solution (mg/mL)

Cᵤ = concentration of Nitrofurazone in the Sample solution (mg/mL)

F = relative response factor (see Table 1)

Acceptance criteria: See Table 1. Disregard any peak less than 0.05%.

Table 1

5 SPECIFIC TESTS

5.1 pH 〈791〉

Sample solution: 1 g of Nitrofurazone in 100 mL of water. Shake for 15 min, allow the suspension to settle, and filter.

Acceptance criteria: 5.0–7.5

5.2 Loss on Drying 〈731〉

Analysis: Dry at 105° for 1 h.

Acceptance criteria: NMT 0.5%

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, light-resistant containers, and avoid exposure to direct sunlight and to excessive heat.

USP Reference Standards 〈11〉

USP Nitrofurantoin RS

USP Nitrofurazone RS

USP Nitrofurazone Related Compound A RS

5-Nitro-2-furfuraldazine

C₁₀H₆N₄O₆   278.18

USP Nitrofurfural Diacetate RS

(5-Nitrofuran-2-yl)methylene diacetate

C₉H₉NO₇   243.17