Capsicum Oleoresin
» Capsicum Oleoresin is an alcoholic extract of the dried ripe fruits of Capsicum annum var. minimum and small fruited varieties of C. frutescens (Solanaceae). It contains not less than 8.0 percent of total capsaicins [capsaicin (C18H27NO3), dihydrocapsaicin (C18H29NO3), and nordihydrocapsaicin (C17H27NO3)].
Caution—Capsicum Oleoresin is a powerful irritant, and even in minute quantities produces an intense burning sensation when it comes in contact with the eyes and tender parts of the skin. Care should be taken to protect the eyes and to prevent contact of the skin with Capsicum Oleoresin.
Packaging and storage— Preserve in tight containers.
Labeling— Label it to indicate that if separation occurs, it should be warmed and mixed before use.
Identification— To about 0.5 g of it in a beaker add 5 mL of water and 10 mL of a mixture of water, 0.2 M potassium chloride, and 0.2 N hydrochloric acid (135:50:13), and mix. Add 5.0 mL of 0.5 M sodium nitrite and 5.0 mL of 0.02 M sodium tungstate, and mix. Heat at 55 to 60 for 15 minutes, allow to cool, and filter. To the filtrate add 10 mL of 1 N sodium hydroxide: a bright yellow color is produced (presence of capsaicin).
Mobile phase— Prepare a mixture of methanol and 2% acetic acid (56:44), filter through a 0.5-µm or finer porosity filter, and degas. Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation— Prepare a solution of USP Capsaicin RS in methanol having a known concentration of about 0.5 mg per mL. Filter a portion of this solution through a 0.2-µm porosity filter, and use the filtrate as the Standard preparation.
Assay preparation— Transfer about 1000 mg of Capsicum Oleoresin, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with methanol to volume, and mix. Filter a portion of this solution through a 0.2-µm porosity filter, and use the filtrate as the Assay preparation.
Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 280-nm detector and a 3.9-mm × 30-cm column that contains packing L1. The flow rate is about 2 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the tailing factor is not more than 2.0; and the relative standard deviation for replicate injections is not more than 2.0%. Chromatograph the Assay preparation, and record the peak responses as directed for Procedure: the relative retention times are about 0.9 for nordihydrocapsaicin, 1.0 for capsaicin, and 1.6 for dihydrocapsaicin; and the resolution, R, between the nordihydrocapsaicin peak and the capsaicin peak is not less than 1.2.
Procedure— [note—Use peak areas where peak responses are indicated.] Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the three major peaks. Calculate the percentage of total capsaicins in the portion of Capsicum Oleoresin taken by the formula:
(CP / W)(rU / rS)
in which C is the concentration, in mg per mL, of USP Capsaicin RS in the Standard preparation; P is the designated purity, in percentage, of USP Capsaicin RS; W is the weight, in mg, of Capsicum Oleoresin taken to prepare the Assay preparation; rU is the sum of the peak responses for nordihydrocapsaicin, capsaicin, and dihydrocapsaicin obtained from the Assay preparation; and rS is the peak response obtained from the Standard preparation.
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Topic/Question Contact Expert Committee
Monograph Maged H. Sharaf, Ph.D.
Senior Scientist
(DSB05) Dietary Supplements - Botanicals
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 1779
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.