White Wax

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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White beeswax

CAS RN^®: 8012-89-3.

1 DEFINITION

White Wax is the product of bleaching and purifying Yellow Wax that is obtained from the honeycomb of the bee [Apis mellifera L. (Fam. Apidae)]. It consists primarily of a mixture of esters of fatty acids and fatty alcohols, hydrocarbons, and free fatty acids; minor amounts of free fatty alcohols are also present.

2 IDENTIFICATION

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197A or 197F. Use melted White Wax when performing 197F.

3 SPECIFIC TESTS

3.1 Ceresin, Paraffins, and Certain Other Waxes

Sample: 3.00 g

Alcoholic potassium hydroxide: Dissolve 40 g of potassium hydroxide in about 900 mL of aldehyde-free alcohol maintained at a temperature not exceeding 15°, and then when solution is complete, warm to room temperature, and add aldehyde-free alcohol to make 1000 mL.

Analysis: Place the Sample in a 100-mL round-bottom boiling flask fitted with a ground-glass joint. Add 30 mL of Alcoholic potassium hydroxide. Reflux the mixture gently for 2 h. At the end of this period, open the flask, insert a thermometer into the solution, and place the flask in a container of water at a temperature of 80°. [Note—A 400-mL beaker filled with about 180 mL of water at 80° may be used.] Rotate the flask in the bath and observe changes of appearance while both the bath and the solution cool.

Acceptance criteria: Upon cooling, no precipitate is formed until 65°, although the solution may be slightly opalescent. Beginning at 65°, the solution may become cloudy and precipitates may be formed. At 59°, the solution is cloudy.

3.2 Melting Range or Temperature 〈741〉, Procedures, Procedure for Class II: 62°–66°

3.3 Fats or Fatty Acids, Japan Wax, Rosin, and Soap

Sample: 1 g

Analysis 1: Boil the Sample for 30 min with 35 mL of 3.5 N sodium hydroxide contained in a 100-mL beaker, maintaining the volume of solution by the occasional addition of water, and allow the mixture to cool at room temperature for about 2 h.

Acceptance criteria 1: The wax separates, leaving the liquid clear, turbid, or translucent, but not opaque.

Analysis 2: Filter the cool mixture obtained in Analysis 1, and acidify the clear filtrate with hydrochloric acid.

Acceptance criteria 2: The liquid remains clear or shows NMT a slight amount of turbidity or precipitate.

3.4 Fats and Fixed Oils 〈401〉, Procedures, Acid Value

Sample: 3 g

Analysis: Warm the Sample in a 200-mL flask with 25 mL of neutralized dehydrated alcohol until melted, then shake the mixture. Add 1 mL of phenolphthalein TS, and titrate the warm liquid with 0.5 N alcoholic potassium hydroxide VS to produce a permanent, faint pink color. Calculate the Acid Value as directed in the chapter.

Acceptance criteria: 17–24

Change to read:

3.5 Fats and Fixed Oils 〈401〉, Procedures, Ester Value

Sample solution: The solution resulting from the determination of Acid Value

Analysis: To the Sample solution add 25.0 mL of 0.5 N alcoholic potassium hydroxide VS and 50 mL of aldehyde-free alcohol, and reflux the mixture for 4 h. Titrate the excess alkali with 0.5 N hydrochloric acid VS. Perform a blank determination (see Titrimetry 〈541〉, Types of Titrations, Blank Corrections (CN 1-Aug-2024) ). Calculate the Ester Value as directed in the chapter.

Acceptance criteria: 68–80

4 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in well-closed containers.

USP Reference Standards 〈11〉

USP White Wax RS