Powdered St.John's Wort Extract
»Powdered St.John's Wort Extract is prepared from comminuted St.John's Wort extracted with 80percent methanol or other suitable solvents.It contains not less than 90.0percent and not more than 110.0percent of the labeled combined total of hypericin (C30H16O8)and pseudohypericin (C30H16O9)and not less than 90.0percent and not more than 110.0percent of hyperforin (C35H52O4).
Packaging and storage— Preserve in tight containers,protected from moisture and light.
Change to read:
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 hypericin,pseudohypericin,and hyperforin;the extracting solvent or solvent mixture used for preparation;and the ratio of the starting crude plant material to Powdered Extract.The label bears a statement indicating that “Rare cases of allergic reactions and photosensitivity have been reported with the use of St.John's Wort.St.John's Wort interacts with numerous medications.Check with your health care provider before using.”USP28
USP Reference standards á11ñ— USP Oxybenzone RS.USP Rutin RS.USP Powdered St.John's Wort Extract RS.
Identification—
A:Thin-Layer Chromatographic Identification Test á201ñ(presence of hypericin,pseudohypericin,hyperoside,and rutin)—
Test solution— Transfer about 1g of Powdered Extract,accurately weighed,to a 50-mLflask,add 20.0mLof methanol,shake well,and use the clear supernatant.
Standard solution— Transfer about 0.25g of USP Powdered St.John's Wort Extract RS,accurately weighed,to a 25-mLflask,add 5.0mLof methanol,shake well,and use the clear supernatant.
Developing solvent system— Prepare a mixture of ethyl acetate,water,glacial acetic acid,and formic acid (10:2.6:1.1:1.1),and use the upper phase of the mixture.[NOTE—Saturate the chromatographic chamber with the Developing solvent systemvapors prior to the development of the chromatogram.]
Spray reagent A— Prepare a solution of diphenylborinic acid,ethanolamine ester in methanol containing 10mg per mL.
Spray reagent B— Prepare a solution of polyethylene glycol 400in alcohol containing 50mg per mL.
Procedure— Develop the chromatogram until the solvent front has moved not less than 18cm,and dry the plate with the aid of a current of air.Spray the plate withSpray reagent A,then withSpray reagent B,and examine the plate under UVlight at 365nm:the two red zones due to hypericin and pseudohypericin atRFvalues of about 0.85and 0.80,respectively,in the chromatogram of theTest solution,correspond in color andRFvalue to those in the chromatogram of theStandard solution;the two yellow zones due to hyperoside and rutin atRFvalues of about 0.50and 0.35,respectively,in the chromatogram of theTest solution,correspond in color andRFvalue to those in the chromatogram of theStandard solution.Other colored zones of varying intensities may be observed in the chromatogram of theTest solution.
B:Thin-Layer Chromatographic Identification Test á201ñ(presence of hyperforin)—
Test solution and Standard solution— Proceed as directed forIdentificationtestA.
Developing solvent system— Prepare a mixture of solvent hexane and ethyl acetate (8:2).[NOTE—Saturate the chromatographic chamber with theDeveloping solvent systemvapors prior to the development of the chromatogram.]
Spray reagent— Prepare a solution containing 0.38g of ceric ammonium sulfate and 3.8g of ammonium molybdate in 100-mLof 2Nsulfuric acid.
Procedure— Develop the chromatogram until the solvent front has moved not less than 18cm,and dry the plate with the aid of a current of air.Spray the plate withSpray reagent,heat the plate at 140for 15minutes,and examine under UVlight:the blue zone due to hyperforin at anRFvalue of about 0.54in the chromatogram of theTest solutioncorresponds in color andRFvalue to that in the chromatogram of theStandard solution.
Water,Method Iá921ñ: not more than 5.0%.
Total ash á561ñ: not more than 7.0%.
Microbial enumeration á2021ñ— It meets the requirements of the tests for absence of Salmonella speciesand Escherichia coli.The total bacterial count does not exceed 104cfu per g,and the total combined molds and yeasts does not exceed 1000cfu per g.
Pesticide residues á561ñ— Proceed as directed forTest for Pesticides under Articles of Botanical Origin á561ñ:meets the requirements.
Content of hypericin and pseudohypericin—
Solution A,Solution B,Solution C,Mobile phase,Standard solution 1,Standard solution 2,and Chromatographic system— Proceed as directed for the Content of hypericin and pseudohypericin test under St.John's Wort.
Test solution— Transfer about 25mg of Powdered Extract,accurately weighed,to a 25-mLvolumetric flask,add about 10mLof a mixture of methanol and water (9:1),and sonicate.Dilute with a mixture of methanol and water (9:1)to volume,and mix.Pass through a polytef membrane filter having a 0.45-µm or finer porosity,and use the filtrate.
Procedure— Proceed as directed for theContent of hypericin and pseudohypericintest under St.John's Wort.Calculate the percentages of hypericin (C30H16O8)and pseudohypericin (C30H16O9)in the portion of Powdered Extract taken by the formula:
2500(C/FW)(rU/rS),
in which Wis the weight,in mg,of Powdered Extract taken to prepare the Test solution;and the other terms are as defined therein.Add the percentages obtained for hypericin and pseudohypericin.
Content of hyperforin— Using the chromatograms obtained in the test forContent of hypericin and pseudohypericin,calculate the percentage of hyperforin (C35H52O4)in the portion of Powdered Extract taken by the formula:
2500(C/W0.46)(rU/rS),
in which 0.46is the response factor of hyperforin,relative to that of oxybenzone;rUis the response of the hyperforin peak in the chromatogram of theTest solution;and the other terms are as defined therein.
Other requirements— It meets the requirements forResidue on Evaporation andResidual Solvents under 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 2126
Pharmacopeial Forum:Volume No.30(2)Page 584
Phone Number:1-301-816-8343