Docusate Sodium Solution

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

Docusate sodium Solution contains NLT 90.0% and NMT 110.0% of the labeled amount of docusate sodium (C₂₀H₃₇NaO₇S).

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.

3 ASSAY

Procedure

Mobile phase: Acetonitrile and 0.01 M tetrabutylammonium dihydrogen phosphate (66:34)

Diluent: Acetonitrile and water (50:50)

Standard solution: 0.1 mg/mL of USP Docusate Sodium RS in Diluent. Filter the solution, discarding the first 6 mL of the filtrate.

Sample stock solution: Transfer a volume of Solution, equivalent to 100 mg of docusate sodium, to a 100-mL volumetric flask, and dilute with Diluent to volume.

Sample solution: Transfer 5.0 mL of the Sample stock solution to a 50-mL volumetric flask, dilute with Diluent to volume, and filter, discarding the first 6 mL of the filtrate.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 214 nm

Column: 4.6-mm × 15-cm; packing L1 that has been highly deactivated (carbon loading of 30%)

Flow rate: 1.5 mL/min

Injection volume: 25 μL

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 2.0

Column eficiency: NLT 1000 theoretical plates

Relative standard deviation: NMT 2%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of docusate sodium (C₂₀H₃₇NaO₇S) in the portion of Solution taken:

Result = (r_U/r_S) × (C_U/C_S) × 100

r_U= peak response from the Sample solution

r_S= peak response from the Standard solution

C_U= concentration of anhydrous docusate sodium in the Standard solution, as determined from the concentration of USP Docusate Sodium RS corrected for moisture by a titrimetric water determination (mg/mL)

C_S= nominal concentration of docusate sodium in the Sample solution (mg/mL)

Acceptance criteria: 90.0%–110.0%

4 SPECIFIC TESTS

pH 〈791〉: 4.5–6.9

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers.

USP Reference Standards 〈11〉

USP Docusate Sodium RS