Milk Thistle Tablets
»Milk Thistle Tablets are prepared from Powdered Milk Thistle Extract.They contain not less than 90.0percent and not more than 110.0percent of the labeled amount of silymarin as silybin (C25H22O10),calculated as the sum of silydianin,silychristin,silybin A,silybin B,isosilybin A,and isosilybin B.
Packaging and storage— Preserve in tight,light-resistant containers.
Labeling— The label states the Latin binomial and,following the official name,the article from which the Tablets were prepared.The label also indicates the content of silymarin,in mg per Tablet.
Identification—
A:Thin-Layer Chromatographic Identification Test á201ñ—
Standard solution,Developing solvent system,and Procedure— Proceed as directed for the Identificationtest under Milk Thistle.
Test solution— Weigh and finely powder not fewer than 20Tablets.Transfer a portion of the powder,equivalent to about 50mg of silymarin,to a test tube,add 10mLof methanol,shake for 1minute,and sonicate for 10minutes.Allow to stand for 15minutes before use.
B: The retention times of the peaks for silydianin,silychristin,silybin A,silybin B,isosilybin A,and isosilybin Bin the chromatogram of the Test solutioncorrespond to those in the chromatogram of Milk thistle standard solution,as obtained in the test for Content of silymarin.
Microbial enumeration á2021ñ— The total bacterial count does not exceed 104cfu per g,the total combined molds and yeasts count does not exceed 103cfu per g,and the enterobacterial count does not exceed 102per g.It meets the requirements of the tests for absence of Salmonellaspecies and Escherichia coli.
Disintegration and dissolution á2040ñ: meet the requirements for Dissolution.Proceed as directed in the test for Dissolutionunder Milk Thistle Capsules.
Weight variation á2091ñ: meet the requirements.
Content of silymarin—
Solution A,Solution B,Mobile phase,Silybin standard solutions,and Chromatographic system— Proceed as directed in the test for Content of silymarinunder Milk Thistle.
Milk thistle standard solution— Prepare as directed for Milk thistle standard solutionin the test for Content of silymarinunder Powdered Milk Thistle Extract.
Test solution— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed quantity of the powder,equivalent to about 100mg of silymarin,to a 100-mLvolumetric flask,add 90mLof methanol,and sonicate for 20minutes with occasional shaking.Cool to 20,and dilute with methanol to volume.Filter through a membrane having a 0.45-µm or finer porosity.
Procedure— Proceed as directed in the test for Content of silymarinunder Milk Thistle,except to separately calculate the amount,in mg,of each relevant component of silymarin as silybin (C25H22O10)in the portion of Tablets taken by the formula:
100C,
in which the term,C,is as defined therein.Calculate the amount of silymarin,in mg,in the portion of Tablets taken by adding the individual amounts obtained.
Auxiliary Information— Staff Liaison:Gabriel I.Giancaspro,Ph.D.,Senior Scientist and Latin American Specialist
Expert Committee:(DSB)Dietary Supplements:Botanicals
USP28–NF23Page 2118
Pharmacopeial Forum:Volume No.28(2)Page 422
Phone Number:1-301-816-8343
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