Caraway Oil

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

Caraway Oil is the volatile oil distilled from the dried, ripe fruit of Carum carvi L. (Fam. Apiaceae). It contains NLT 50.0% of d-carvone (C₁₀H₁₄O).

2 ASSAY

2.1 PROCEDURE

Sample: 10 mL of Caraway Oil

Analysis: Transfer the Sample to a cassia flask, and add 50 mL of a saturated solution of sodium sulfite that has been made neutral to 2 drops of phenolphthalein TS by means of a saturated sodium bisulfite solution. Heat the flask in boiling water, and shake it repeatedly, neutralizing the mixture from time to time by adding a few drops of the saturated sodium bisulfite solution. When no coloration appears upon the addition of a few more drops of phenolphthalein TS and heating for 15 min, cool the mixture to room temperature. When the liquids have separated more completely, add a sufficient volume of the saturated sodium bisulfite solution to raise the lower level of the oily layer to the graduated portion of the neck of the flask.

Acceptance criteria: The volume of the residual oily liquid does not exceed 5 mL, indicating the presence of NLT 50.0% of d-carvone (C₁₀H₁₄O) in the portion of Oil taken.

3 SPECIFIC TESTS

SOLUBILITY IN 80% ALCOHOL: One volume dissolves in 8 volumes of 80% alcohol.

SPECIFIC GRAVITY (841): 0.900-0.910

OPTICAL ROTATION, Angular Rotation(781A): +70° to +80°

REFRACTIVE INDEX (831): 1.484-1.488 at 20°

4 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight, light-resistant containers.

LABELING: The label states the Latin binomial and, following the official name, the part of the plant source from which the article was derived.