Caprylic Acid

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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C₈H₁₆O₂ 144.21

Octanoic acid;

1-Heptanecarboxylic acid CAS RN®: 124-07-2.

1 DEFINITION

Caprylic Acid contains NLT 99.0% of caprylic acid (C₈H₁₆O₂), calculated on the anhydrous basis.

2 IDENTIFICATION

Change to read:

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

B. 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

Change to read:

PROCEDURE

Standard solution: 10 mg/mL of USP Caprylic Acid RS in ethyl acetate

Sample solution: 10 mg/mL of Caprylic Acid in ethyl acetate

System suitability solution: 10 µg/mL of Caprylic Acid in ethyl acetate, prepared from the Sample solution

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: GC

Detector: Flame ionization

Column: 0.25-mm x 30-m (ERR 1-May-2020) fused silica capillary column bonded with a 0.25-µm layer of phase G25

Temperatures

Detector: 250°

Injection port: 250°

Column: See Table 1.

Table 1

Carrier gas: Helium

Flow rate: 1.5 mL/min

Injection volume: 1 μL

Injection type: Split injection. The split ratio is about 1:100.

System suitability

Samples: Standard solution and System suitability solution

Suitability requirements

Relative standard deviation: NMT 2.0%, Standard solution

Signal-to-noise ratio: NLT 5 for the major peak, System suitability solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of caprylic acid (C₈H₁₆O₂ ) in the portion of Caprylic Acid taken:

Result = (r_U/r_S ) × (C_s/C_U ) × 100

r_U = peak response of caprylic acid from the Sample solution

r_S = peak response of caprylic acid from the Standard solution

C_s = concentration of USP Caprylic Acid RS in the Standard solution (mg/mL)

C_U = concentration of Caprylic Acid in the Sample solution (mg/mL)

Acceptance criteria: NLT 99.0% on the anhydrous basis

4 IMPURITIES

Residue on Ignition 〈281〉: NMT 0.1%

Limit of Related Linear and Branched Alkyl Carboxylic Acids, Related Esters, Cyclic Esters and Ketone

Standard solution, System suitability solution, Sample solution, Chromatographic system, and System suitability: Proceed as directed in the Assay.

Analysis

Sample: Sample solution

Calculate the percentage of each impurity in the portion of Caprylic Acid taken:

Result = (r_U /r_T ) × 100

r_U = peak response of each individual impurity in the Sample solution

r_T = sum of all the peaks except the peak due to solvent and peaks below the Disregard limit (see Table 2) in the Sample solution

Acceptance criteria: See Table 2.

Disregard any peak with an area less than 0.5 times the area of the major peak from the System suitability solution.

Table 2

5 SPECIFIC TESTS

Bacterial Endotoxins Test 〈85〉: The level of bacterial endotoxins is such that the requirement in the relevant dosage form monograph(s) in which Caprylic Acid is used can be met. Where the label states that Caprylic Acid must be subjected to further processing during the preparation of injectable dosage forms, the level of bacterial endotoxins is such that the requirement in the relevant dosage form monograph(s) in which Caprylic Acid is used can be met.

Fats and Fixed Oils, Peroxide Value 〈401〉: NMT 10.0

Water Determination, Method Ia 〈921〉: NMT 0.7%

ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers, and store at room temperature.

Labeling: Where Caprylic Acid must be subjected to further processing during the preparation of injectable dosage forms to ensure acceptable levels of bacterial endotoxins, it is so labeled.

USP Reference Standards 〈11〉

USP Caprylic Acid RS