Powdered Red Clover Extract
»Powdered Red Clover Extract is prepared from Red Clover by extraction with hydroalcoholic mixtures or other suitable solvents.The ratio of plant material to extract is between 3:1and 25:1.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of isoflavones,calculated on the dried basis as the sum of daidzein,genistein,formononetin,and biochanin A.It may contain suitable added substances.
Packaging and storage— Preserve in tight,light-resistant containers,in a cool place.
Labeling— The label states the Latin binomial and,following the official name,the part of the plant from which the article was prepared.The label also indicates the content of isoflavones,the extracting solvent or solvent mixture used for preparation,and the ratio of the starting crude plant material to Powdered Extract.It meets the requirements for labeling under Botanical Extracts á565ñ.
Identification—
A:Thin-Layer Chromatographic Identification Test á201ñ—
Standard solution,Developing solvent system,Spray reagent A,Spray reagent B,and Procedure— Proceed as directed forThin-Layer Chromatographic Identification Test á201ñunderRed Clover.
Test solution— Shake a quantity of Powdered Extract,equivalent to 25mg of the labeled amount of isoflavones,in 20mLof methanol.Allow to stand for 15minutes before use.
B: The chromatogram of the Test solutionexhibits peaks for daidzein,genistein,formononetin,and biochanin Aat retention times that correspond to those in the chromatogram of Standard solution 1,as obtained in the test for Content of isoflavones.Calculate the ratio of 5,7-dihydroxyisoflavones to 7-hydroxyisoflavones by the formula:
(B+G)/(D+F),
in which B,G,D,and Fare the percentages of biochanin A,genistein,daidzein,and formononetin,respectively,as obtained in the test for Content of isoflavones:the ratio is between 0.1and 10.0.
Microbial enumeration á2021ñ— It meets the requirements of the tests for absence of Salmonellaspecies and Escherichia coli.The total aerobic microbial count does not exceed 104cfu per g,the total combined molds and yeasts count does not exceed 1000cfu per g,and the enterobacterial count is not more than 1000cfu per g.
Change to read:
Loss on drying á731ñ: Dry 1g at 105for 2hours.It losesUSP28not more than 5.0%.
Heavy metals,Method IIá231ñ: not more than 10µg per g.
Content of isoflavones—
Solvent,Solution A,Solution B,Standard solution 1,Standard solution 2,andChromatographic system— Proceed as directed underRed Clover.
Test solution— Transfer an accurately weighed quantity of Powdered Extract,equivalent to about 30mg of the labeled content of isoflavones,to a 250-mLvolumetric flask.Add 15mLof dehydrated alcohol,sonicate until dissolved,dilute with Solventto volume,and mix.Transfer 50.0mLof this solution to a round-bottom flask,and evaporate to dryness under vacuum.Add 15mLof 2Nhydrochloric acid,and heat in a water bath for 30minutes.Quantitatively transfer the resulting solution with the aid of about 15mLof alcohol to a 50-mLvolumetric flask,and dilute with Solventto volume.Centrifuge,or pass through a filter having a 0.45-µm or finer porosity.
Procedure— Proceed as directed underRed Clover.Separately calculate the percentage of each relevant isoflavone component in the portion of Powdered Extract taken by the formula:
25F(C/W)(rU/rS),
in which Wis the weight,in g,of Powdered Extract taken to prepare the Test solution;and the other terms are as defined therein.Calculate the percentage of isoflavones in the Powdered Extract taken by adding the individual quantities calculated.
Other requirements— It meets the requirements forPackaging and Storage,Residual Solvents,andPesticide Residuesunder Botanical Extracts á565ñ.
Auxiliary Information— Staff Liaison:Gabriel I.Giancaspro,Ph.D.,Senior Scientist and Latin American Specialist
Expert Committee:(DSB)Dietary Supplements:Botanicals
USP28–NF23Page 2072
Pharmacopeial Forum:Volume No.30(2)Page 552
Phone Number:1-301-816-8343