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Soy Isoflavones Capsules
» Soy Isoflavones Capsules contain Powdered Soy Isoflavones Extract. Capsules contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of the Extract, represented by the sum of the content of the isoflavones daidzin, glycitin, genistin and one or more of the following isoflavones: malonyl daidzin, malonyl glycitin, malonyl genistin, acetyl daidzin, acetyl glycitin, acetyl genistin, daidzein, glycitein, and genistein.
Packaging and storage— Preserve in tight, light-resistant containers, and store at room temperature.
Labeling— The label states the Latin binomial and, following the official name, the article from which the Capsules were prepared. Label it to indicate the amount of Extract, in mg, per Capsule. Label it to indicate the content, in percentage, of the isoflavones in the Extract used to prepare the Capsules.
USP Reference standards 11—
USP Apigenin RS.
USP Daidzein RS.
USP Daidzin RS.
USP Genistein RS.
USP Genistin RS.
USP Glycitein RS.
USP Glycitin RS.
USP Defatted Powdered Soy RS.
Identification— The retention times of the daidzin, glycitin, and genistin peaks in the chromatogram of the Test solution correspond to those in the chromatogram of the Working standard solutions, as obtained in the test for Content of isoflavones.
Weight variation 2091: meet the requirements.
Disintegration 2040: meet the requirements under Botanical Dosage Forms.
Microbial limits 2021— The total aerobic microbial count does not exceed 104 cfu per g, and the total combined molds and yeasts count does not exceed 103 cfu per g.
Absence of specified microorganisms 2022— Capsules meet the requirements of the tests for absence of Salmonella species and Escherichia coli.
Content of isoflavones—
Diluting solution, Internal standard solution, Solution A, Solution B, Mobile phase, Stock standard solution, Working standard solutions, Malonyl/acetyl isoflavones retention times check solutions, and Chromatographic system— Proceed as directed in the test for Content of isoflavones under Powdered Soy Isoflavones Extract.
Test solution—
hard-gelatin capsules— Weigh and finely powder the content of not fewer than 20 Capsules. Transfer an accurately weighed quantity of the powder, equivalent to not more than 5 mg of soy isoflavones, to a suitable glass centrifuge tube, fitted with PTFE or polyethylene-lined screw caps. Proceed as directed for the Test solution under Powdered Soy Isoflavones Extract, starting with “Add the following in exact volumes: 0.5 mL of Internal standard solution,”.
soft-gelatin capsules— Weigh and homogenize not fewer than 20 Capsules. Transfer an accurately weighed quantity of the mixture, equivalent to not more than 5 mg of soy isoflavones, to a suitable glass centrifuge tube, fitted with PTFE or polyethylene-lined screw caps. Proceed as directed for the Test solution under Powdered Soy Isoflavones Extract, starting with “Add the following in exact volumes: 0.5 mL of Internal standard solution,”.
Procedure— Proceed as directed in the test for Content of isoflavones under Powdered Soy Isoflavones Extract. From the graphs obtained, determine the concentration, C, in mg per mL, of daidzin, glycitin, and genistin, in addition to daidzein, glycitein, and genistein, if present. From the graphs obtained for daidzin, glycitin, and genistin, determine the concentration, C, in mg per mL, of the corresponding malonyl and acetyl derivatives, if present, by the formula:
F(Cobserved)
in which F is the conversion factor for each analyte (1.207 for malonyl daidzin, 1.101 for acetyl daidzin, 1.193 for malonyl glycitin, 1.094 for acetyl glycitin, 1.199 for malonyl genistin, and 1.097 for acetyl genistin); and Cobserved is the concentration obtained from the relevant graph. Calculate the quantity, in mg, of isoflavones in the portion of Capsules taken by the formula:
25(CT)
in which CT is the sum of concentrations (C) of all relevant isoflavones; and C is as defined above.USP32
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Maged H. Sharaf, Ph.D.
Senior Scientist
1-301-816-8318		 (DSB05) Dietary Supplements - Botanicals
Reference Standards Lili Wang, Technical Services Scientist
1-301-816-8129
RSTech@usp.org
2021 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
1-301-816-8339		 (MSA05) Microbiology and Sterility Assurance
2022 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
1-301-816-8339		 (MSA05) Microbiology and Sterility Assurance
USP32–NF27 Page 1076
Pharmacopeial Forum: Volume No. 33(6) Page 1227
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.