Sulfacetamide Sodium

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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1 DEFINITION

Sulfacetamide Sodium contains NLT 99.0% and NMT 100.5% of sulfacetamide sodium (C₈H₉N₂NaO₃S), calculated on the anhydrous basis.

2 IDENTIFICATION

A. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

B. Identification Tests—General 〈191〉, Sodium

Sample solution: 1 g in 25 mL of water

Analysis: Adjust the Sample solution with 6 N acetic acid to a pH of 4–5, and filter. Wash the precipitate with water, and use the filtrate.

Acceptance criteria: The filtrate responds to test A.

C.

Sample solution: 100 mg in 5 mL of water

Analysis: Add 5 drops of cupric sulfate TS to the Sample solution.

Acceptance criteria: A light bluish green precipitate is formed, and it remains unchanged on standing.

D.

Sample solution: 500 mg in 10 mL of dilute hydrochloric acid (1 in 10)

Analysis 1: To about one-half of the Sample solution add 2 mL of trinitrophenol TS.

Acceptance criteria 1: A very heavy flocculent or almost gelatinous precipitate is formed.

Analysis 2: To the remainder of the Sample solution add 3 drops of formaldehyde TS.

Acceptance criteria 2: A white precipitate is formed, and it changes to orange on standing (distinction from sulfamethoxypyridazine).

3 ASSAY

Procedure

Solution A: 1% glacial acetic acid

Solution B: Methanol

Mobile phase: See Table 1.

Standard solution: 0.2 mg/mL of USP Sulfacetamide Sodium RS in water

Sample solution: 0.2 mg/mL of Sulfacetamide Sodium in water

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 15-cm; 5-μm packing L1

Flow rate: 0.8 mL/min

Injection volume: 10 μL

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: 0.9–1.8

Relative standard deviation: NMT 0.5% for sulfacetamide

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of sulfacetamide sodium in the portion of Sulfacetamide Sodium taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response of sulfacetamide from the Sample solution

r_S = peak response of sulfacetamide from the Standard solution

C_S = concentration of USP Sulfacetamide Sodium RS in the Standard solution (mg/mL)

C_U = concentration of Sulfacetamide Sodium in the Sample solution (mg/mL)

Acceptance criteria: 99.0%–100.5% on the anhydrous basis

4 IMPURITIES

Delete the following:

Selenium 〈291〉

Sample: 200 mg

Acceptance criteria: 30 ppm (USP 1-Dec-2021)

Organic Impurities

Mobile phase: Methanol, water, and glacial acetic acid (10:89:1)

System suitability solution: 0.2 mg/mL of USP Sulfacetamide Sodium RS and 0.05 mg/mL of USP Sulfanilamide RS in Mobile phase

Standard solution: 2 μg/mL of USP Sulfacetamide Sodium RS and 4 μg/mL of USP Sulfanilamide RS in Mobile phase

Sample solution: 2 mg/mL of Sulfacetamide Sodium in Mobile phase

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 15-cm; 5-μm packing L1

Flow rate: 0.8 mL/min

Injection volume: 10 μL

System suitability

Samples: System suitability solution and Standard solution

Suitability requirements

Resolution: NLT 5.0 between sulfacetamide and sulfanilamide, System suitability solution

Tailing factor: NMT 1.5 for sulfacetamide, Standard solution

Relative standard deviation: NMT 2.0% for sulfacetamide, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of sulfanilamide in the portion of Sulfacetamide Sodium taken:

Result = (r_U/r_S) × (C_cc/C_U) × 100

r_U = peak response of sulfanilamide from the Sample solution

r_S = peak response of sulfanilamide from the Standard solution

C_S = concentration of USP Sulfanilamide RS in the Standard solution (mg/mL)

C_U = concentration of Sulfacetamide Sodium in the Sample solution (mg/mL)

Calculate the percentage of any unspecified impurity in the portion of Sulfacetamide Sodium taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response of any unspecified impurity from the Sample solution

r_S = peak response of sulfacetamide from the Standard solution

C_S = concentration of USP Sulfacetamide Sodium RS in the Standard solution (mg/mL)

C_U = concentration of Sulfacetamide Sodium in the Sample solution (mg/mL)

Acceptance criteria: See Table 2.

Table 2

5 SPECIFIC TESTS

pH 〈791〉

Sample solution: 50 mg/mL

Acceptance criteria: 8.0–9.5

Water Determination 〈921〉, Method I: NMT 8.1%

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, light-resistant containers.

USP Reference Standards 〈11〉

USP Sulfacetamide Sodium RS

USP Sulfanilamide RS