Polyoxyl Lauryl Ether

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

Polyoxyl Lauryl Ether is a mixture of the monolauryl ethers of mixed polyethylene glycols, the average polymer length being equivalent to NLT 3 and NMT 23 oxyethylene units (nominal value). It contains various amounts of free lauryl alcohol, and it may contain some free polyethylene glycols.

2 IDENTIFICATION

Change to read:

A. ▲Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197F ▲ (CN 1-May-2020)

Sample: Use a thin film of melted Polyoxyl Lauryl Ether if the material is a solid.

Acceptance criteria: Meets the requirements

B. Procedure

Sample: 0.1 g

Analysis: Dissolve or disperse the Sample in 5 mL of alcohol, and add 10 mL of diluted hydrochloric acid, 5 mL of barium chloride TS, and 10 mL of phosphomolybdic acid solution (1 in 10).

Acceptance criteria: A precipitate is formed.

C. It meets the requirements of the test for Fats and Fixed Oil, Hydroxyl Values 〈401〉.

3 IMPURITIES

Organic Impurities

Procedure: Limit of Free Ethylene Oxide and Dioxane

Analysis: Proceed as directed in Ethylene Oxide and Dioxane, Method I 〈228〉.

Acceptance criteria

Ethylene oxide: NMT 1 µg/g (ppm)

Dioxane: NMT 10 µg/g (ppm)

4 SPECIFIC TESTS

Alkalinity

Sample: 2.0 g of Polyoxyl Lauryl Ether

Analysis: Dissolve the Sample in a hot mixture of 10 mL of alcohol and 10 mL of water. Add 0.05 mL of bromothymol blue TS, and titrate with 0.1 N hydrochloric acid to a yellow endpoint.

Acceptance criteria: NMT 0.5 mL of 0.1 N hydrochloric acid is required.

Appearance of Solution:

5.0 g of Polyoxyl Lauryl Ether in 50.0 mL of alcohol. The solution is not more intensely colored than a solution prepared immediately before use by mixing 12.0 mL of ferric chloride CS, 5.0 mL of cobaltous chloride CS, and 2.0 mL of cupric sulfate CS with dilute hydrochloric acid (10 g/L) to make 50.0 mL, and diluting 12.5 mL of this solution with dilute hydrochloric acid (10 g/L) to make 100.0 mL. Make the comparison by viewing the substance and the solution downward in matched color-comparison tubes against a white surface (see Color and Achromicity 〈631〉).

Articles of Botanical Origin, Total Ash 〈561〉: NMT 0.2%, determined on 2.0 g

 Fats and Fixed Oils, Acid Value 〈401〉: NMT 1.0, determined on 5.0 g

Fats and Fixed Oils, Hydroxyl Value 〈401〉: Within the ranges specified in the accompanying table

Table: Hydroxyl Value

Fats and Fixed Oils, Iodine Value 〈401〉: NMT 2.0

Fats and Fixed Oils, Saponification Value 〈401〉: NMT 3.0, determined on 10.0 g

Water Determination, Method I 〈921〉: NMT 3.0%

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers, and store in a cool, dry place.

Labeling: Label it to indicate the average nominal number of oxyethylene units.

USP Reference Standards 〈11〉

USP Polyoxyl 4 Lauryl Ether RS

USP Polyoxyl 9 Lauryl Ether RS

USP Polyoxyl 23 Lauryl Ether RS