Labeling—
The label states the Latin binomial and, following the official name, the parts of the plant from which the article was prepared. The label bears a statement indicating that
Echinacea pallida may cause rare allergic reactions, rashes, or aggravate asthma. It meets the requirements for
Labeling under
Botanical Extracts 
565
.
Identification—
A: Thin-Layer Chromatographic Identification Test 201—
Standard solution 2, Developing solvent system, Spray reagent 1, Spray reagent 2, and Procedure—
Proceed as directed for Identification test A under Echinacea angustifolia.
Test solution—
Dissolve 1.0 g of Powdered Extract in 10 mL of methanol. Allow to settle before use.
Standard solution 1—
Dissolve an accurately weighed quantity of USP Powdered Echinacea pallida Extract RS in methanol to obtain a solution having a known concentration of about 100 mg per mL.
B:
The retention time of the major peak in the chromatogram of the Test solution corresponds to that of the echinacoside peak in the chromatogram of Standard solution 1, as obtained in the test for Content of total phenols.
Content of total phenols—
Solvent, Solution A, Solution B, Mobile phase, and Standard solution 2—
Proceed as directed for Content of total phenols under Echinacea angustifolia.
Standard solution 1—
Proceed as directed for Content of total phenols under Echinacea angustifolia, except to use USP Powdered Echinacea pallida Extract RS instead of USP Powdered Echinacea angustifolia Extract RS.
Test solution—
Transfer about 60 mg of Powdered Extract, accurately weighed, to an appropriate round-bottom flask equipped with a condenser. Add 25.0 mL of Solvent, and heat under reflux while shaking by mechanical means for 15 minutes. Centrifuge, or pass through a membrane filter having a 0.45-µm or finer porosity.
Chromatographic system—
Prepare as directed for Content of total phenols under Echinacea angustifolia. Chromatograph Standard solution 1, and record the peak responses as directed for Procedure: the chromatogram obtained is similar to the Reference Chromatogram for total phenols provided with USP Powdered Echinacea pallida Extract RS. Chromatograph Standard solution 2, and record the peak responses as directed for Procedure: the capacity factor, k¢, is not less than 3.0; the tailing factor is not more than 2.0; and the relative standard deviation for replicate injections is not more than 2.5%.
Procedure—
Proceed as directed for
Content of total phenols under
Echinacea angustifolia. Separately calculate the percentage of each relevant component of total phenols in the portion of Powdered Extract taken by the formula:
2500F(C/W)(ri / rS),
in which
F is the response factor and is equal to 0.695 for chicoric acid, 0.881 for caftaric acid, 1.000 for chlorogenic acid, and 2.220 for echinacoside;
C is the concentration, in mg per mL, of
USP Chlorogenic Acid RS in
Standard solution 2; W is the weight, in mg, of the portion of Powdered Extract taken; and
ri and
rS are the peak responses for the relevant analyte obtained from the
Test solution and
Standard solution 2, respectively. Calculate the percentage of total phenols in the portion of Powdered Extract taken by adding the individual percentages calculated.
