Dimethyl Sulfoxide Irrigation

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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Dimethyl sulfoxide Irrigation is a sterile solution of Dimethyl Sulfoxide in Water for Injection. It contains NLT 95.0% and NMT 105.0% of the labeled amount of dimethyl sulfoxide (C₂H₆OS).

1 IDENTIFICATION

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

2 ASSAY

Change to read:

2.1 Procedure

Diluent: 1 mg/mL of ethyl benzoate in methanol

Standard solution: 1 mg/mL of USP Dimethyl Sulfoxide RS in Diluent

Sample solution: Nominally equivalent to 1 mg/mL of dimethyl sulfoxide from Dimethyl Sulfoxide Irrigation in Diluent

Chromatographic system

• (See Chromatography 〈621〉, System Suitability.)
• Mode: GC
• Detector: Flame ionization
• Column: 0.53-mm × 30-m capillary column coated with a 3-µm film of phase G43
• Temperatures
• Injection port: 250°
• Detector: 250°
• Column: See Table 1.

Table 1

• Carrier gas: Hydrogen
• Flow rate: 5 mL/min
• Injection volume: 1 µL
• Injection type: Split, split ratio 5:1

System suitability

• Sample: Standard solution
• [Note-The relative retention times for dimethyl sulfoxide and ethyl benzoate are 1.0 and 1.8, respectively.]
• Suitability requirements
• Tailing factor: NMT 1.5 for dimethyl sulfoxide
• Relative standard deviation: NMT 0.5% for the peak response ratio of dimethyl sulfoxide to ethyl benzoate

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of dimethyl sulfoxide (C₂H₆OS) in the portion of Dimethyl Sulfoxide Irrigation taken:

Result = (Rᵤ/Rₛ) × (Cₛ/Cᵤ) × 100

Rᵤ = peak response ratio of dimethyl sulfoxide to ethyl benzoate from the Sample solution

Rₛ = peak response ratio of dimethyl sulfoxide to ethyl benzoate from the Standard solution

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

Cᵤ = nominal concentration of dimethyl sulfoxide in the Sample solution (mg/mL)

Acceptance criteria: 95.0%–105.0%

3 SPECIFIC TESTS

3.1 pH 〈791〉

Sample solution: Nominally equivalent to 50 mg/mL of dimethyl sulfoxide from Irrigation in water

Acceptance criteria: 5.0–7.0

3.2 Sterility Tests 〈71〉: Meets the requirements

Change to read:

3.3 Bacterial Endotoxins Test 〈85〉: Meets the requirements

4 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in single-dose containers. Store at controlled room temperature, protected from strong light.

Labeling: Label it to indicate prominently that it is not intended for injection.

USP Reference Standards 〈11〉

USP Dimethyl Sulfoxide RS