Labeling—
The label states the Latin binomial and, following the official name, the parts of the plant from which the article was prepared. If derived from root and aerial parts, indicate the corresponding percentages. Label it to indicate the content of total phenols and dodecatetraenoic isobutylamides. The label bears a statement indicating that
Echinacea purpurea 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—
Test solution—
Weigh and finely pulverize about 10 g of Powdered Extract, and transfer 1 g of the powder to a suitable extraction thimble. Transfer the thimble to a continuous extraction apparatus, and extract with 50 mL of chloroform for 1 hour. Evaporate the chloroform extract to dryness at 40
in vacuum. To the residue, add 1 mL of alcohol, and pass through a nylon membrane filter having a porosity of 0.45 µm.
Standard solution 1—
Dissolve an accurately weighed quantity of USP Powdered Echinacea purpurea Extract RS in methanol to obtain a solution having a known concentration of about 100 mg per mL.
Standard solution 2, Developing solvent system, Spray reagent, and Procedure—
Proceed as directed for
Identification test
B under
Echinacea angustifolia.
B:
The retention times of the peaks for chicoric and caftaric acids in the chromatogram of the Test solution correspond to those 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, Standard solution 2, and Chromatographic system—
Proceed as directed for
Content of total phenols under
Echinacea angustifolia.
Standard solution 1—
Dissolve an accurately weighed quantity of USP Powdered Echinacea purpurea Extract RS in Solvent, shaking for 1 minute, and dilute with Solvent to obtain a solution having a known concentration of about 5 mg per mL. Pass through a membrane filter having a 0.45-µm or finer porosity.
Test solution—
Transfer about 60 mg of Powdered Extract, accurately weighed, to a suitable round-bottom flask equipped with a condenser. Add 25 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.
Procedure—
Proceed as directed in the test for
Content of total phenols under
Echinacea purpurea Root. 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;
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.
Content of dodecatetraenoic acid isobutylamides—
Mobile phase and Standard solution 2—
Proceed as directed for
Content of dodecatetraenoic acid isobutylamides under
Echinacea angustifolia.
Standard solution 1—
Proceed as directed for
Content of dodecatetraenoic acid isobutylamides under
Echinacea angustifolia, except to use USP Powdered
Echinacea purpurea Extract RS instead of USP Powdered
Echinacea angustifolia Extract RS.
Test solution—
Proceed as directed for
Content of dodecatetraenoic acid isobutylamides under
Echinacea angustifolia, except to use Powdered
Echinacea purpurea Extract instead of Powdered
Echinacea angustifolia Extract.
Chromatographic system—
Proceed as directed for Content of dodecatetraenoic acid isobutylamides under Echinacea angustifolia, except to use the Reference Chromatogram for alkamides provided with USP Powdered Echinacea purpurea Extract RS instead of the Reference Chromatogram provided with USP Powdered Echinacea angustifolia Extract RS.
Procedure—
Proceed as directed in the test for
Content of dodecatetraenoic acid isobutylamides under
Echinacea angustifolia. Calculate the percentage of dodecatetraenoic acid isobutylamides in the portion of Powdered Extract taken by the formula:
10(1.353)(C/W)(ri / rS),
in which 1.353 is the response factor for 2
E,4
E-hexadienoic acid isobutylamide;
C is the concentration, in mg per mL, of USP 2
E,4
E-Hexadienoic Acid Isobutylamide RS in
Standard solution 2; W is the weight, in g, of the portion of Powdered Extract taken;
ri is the sum of the peak responses of the relevant analytes obtained from the
Test solution; and
rS is the peak response obtained from
Standard solution 2.
