Caprylocaproyl Polyoxylglycerides

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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Former Title: Caprylocaproyl Macrogolglycerides

1 DEFINITION

Caprylocaproyl Polyoxylglycerides is a mixture of monoesters, diesters, and triesters of Glycerol and monoesters and diesters of polyethylene glycols. The polyethylene glycols used have a mean molecular weight between 200 and 400. It is produced by partial alcoholysis of medium-chain triglycerides with polyethylene glycol, by esterification of glycerol and polyethylene glycol with caprylic acid and capric acid, or as a mixture of glycerol esters and ethylene oxide condensate with caprylic acid and capric acid. It may contain free polyethylene glycols.

2 IDENTIFICATION

Change to read:

2.1 A. SPECTROSCOPIC IDENTIFICATION TESTS (197), Infrared Spectroscopy: 197F (CN 1-MAY-2020)

2.2 B. THIN-LAYER CHROMATOGRAPHIC IDENTIFICATION TEST (201).

Standard solution: 50 mg/mL of USP Caprylocaproyl Caprylocaproyl Polyoxylglycerides RS in methylene chloride

Sample solution: 50 mg/mL of Caprylocaproyl Polyoxylglycerides in methylene chloride

Application volume: 50 µL

Developing solvent system: Ether and hexanes (7:3)

Spray reagent: 0.1 mg/mL of rhodamine B in alcohol

Analysis

Samples: Standard solution and Sample solution

Proceed as directed in the chapter. Then spray the plate with Spray reagent, and locate the spots on the plate by examination under UV light at a wavelength of 365 nm.

Acceptance criteria: The R, values of the principal spots of the Sample solution correspond to those of the Standard solution.

2.3 C. It meets the requirements of the test for Fats and Fixed Oils (401), Fatty Acid Composition.

3 IMPURITIES

3.1 ARTICLES OF BOTANICAL ORIGIN, Total Ash (561): NMT 0.1%

3.2 ALKALINE IMPURITIES

Sample: 5.0 g of Caprylocaproyl Polyoxylglycerides

Analysis: To the Sample add 10 mL of alcohol and 0.05 mL of bromophenol blue TS, and mix well. Titrate with 0.01 N hydrochloric acid VS to

change the color to yellow.

Acceptance criteria: NMT 1.0 mL of 0.01 N hydrochloric acid is required.

3.3 LIMIT OF FREE ETHYLENE OXIDE AND DIOXANE

Analysis: Proceed as directed in Ethylene Oxide and Dioxane (228), Method I.

Acceptance criteria

• Ethylene oxide: NMT 1 µg/g
• Dioxane: NMT 10 µg/g

3.4 LIMIT OF FREE GLYCEROL

Sample: 1.20 g

Blank: 25 mL of methylene chloride

Periodic acetic acid solution: Dissolve 0.446 g of sodium periodate in 2.5 mL of a 25% (v/v) solution of sulfuric acid, and dilute with glacial

acetic acid to 100.0 mL..

Potassium iodide solution: 75 mg/ml. of potassium iodide

Titrimetric system

(See Titrimetry (541).)

• Mode: Residual titration
• Titrant: 0.1 M sodium thiosulfate

Analysis: Dissolve the Sample in 25 mL of methylene chloride, heating if necessary. Cool, and add 100 mL of water and 25.0 mL of Periodic acetic acid solution. Shake, and allow to stand for 30 min. Add 40 mL of Potassium iodide solution, and allow to stand for 1 min. Add 1 mL of starch TS, and titrate the liberated iodine with Titrant. Perform a blank determination.

Calculate the percentage of free glycerol in the portion of Caprylocaproyl Polyoxylglycerides taken:

Result = [(V_B - V_S) x N x E x F/W) x 100

V_B = Titrant volume consumed by the Blank (mL)

V_S = Titrant volume consumed by the Sample (mL).

N = actual normality of the Titrant (mEq/mL)

E = equivalency factor for glycerol, 23 mg/mEq

F = unit conversion factor, 10^-3 g/mg

W = Sample weight taken for the titration (g)

Acceptance criteria: NMT 5.0%

4 SPECIFIC TESTS

FATS AND FIXED OILS, Acid Value (401): NMT 2.0, determined on a 2.0-g specimen

FATS AND FIXED OIus, Fatty Acid Composition (401); Caprylocaproyl Polyoxylglycerides exhibit the composition profile of fatty acids shown in Table 1, as determined in the section Fatty Acid Composition under Fats and Fixed Oils (401).

FATS AND FIXED OILS, Hydroxyl Value (401): The hydroxyl value is within the range specified in Table 2 for the labeled type, when determined on a 1.0-g specimen.

FATS AND FIXED OILS, Jodine Value (401): NMT 2.0

FATS AND FIXED OILS, Peroxide Value (401): NMT 6.0, determined on a 2.0-g specimen

FATS AND FIXED OILS, Saponification Value (401): The saponification value is within the range specified in Table 3 for the labeled type, determined on a 2.0-g specimen.

WATER DETERMINATION, Method (921): NMT 1.0%, determined on a 1.0-g specimen. Use as the solvent anhydrous pyridine or a mixture of methylene chloride and anhydrous methanol (7:3).

5 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight containers, protected from light and moisture. Store at controlled room temperature.

LABELING: Label it to indicate the type and the average nominal molecular weight of polyethylene glycol used, or to indicate the number of ethylene oxide units per molecule (nominal value), as part of the official title.

USP REFERENCE STANDARDS (11)

USP Caprylocaproyl Polyoxylglycerides RS