Measurements and Standards for Botanical Dietary Supplements

Summary

As part of a multi-year interagency agreement among the National Institute of Standards and Technology (NIST), the National Institutes of Health's Office of Dietary Supplements (NIH/ODS), the Food and Drug Administration (FDA) Center for Food Safety and Applied Nutrition (CFSAN), and the FDA Center for Drug Evaluation and Research (CDER), NIST is developing Standard Reference Materials (SRMs) for botanical dietary supplements.

SRMs with assigned values for concentrations of active and/or marker compounds, pesticides, and toxic elements are being produced to assist in the verification of manufacturers' label claims and for use in quality control during the manufacturing process in support of the Good Manufacturing Practices released by the FDA in 2007.

Description

Many consumers believe that botanical dietary supplements will improve their health and that these "natural" remedies are both effective and free from the side effects that may occur with other medications. There are occasional reports of inaccurate labeling, adulteration, contamination (with pesticides, heavy metals, or toxic botanicals), and drug interactions. Congress recognized the lack of publicly available, validated analytical methods for dietary supplements – and a lack of reference materials for validation of analytical methods – in 1994 when the Dietary Supplement Health and Education Act (DSHEA) was enacted. As part of DSHEA, NIH/ODS was directed to fund development of analytical methods and reference materials for dietary supplements. NIST's dietary supplement program began in 2001 as a collaborative effort between NIST and NIH/ODS to underpin the then-anticipated GMPs. Subparts E and J of the GMPs require manufacturers to establish specifications for identity, purity, strength, and composition; to set limits on contaminants and adulterants for every ingredient in their products; and to analyze both "materials in process" and finished products to determine whether specifications are met. The validity of analytical methods must be verified and then routinely used for monitoring against the manufacturer's specifications. Thus, the SRMs can be used both to demonstrate that a method is appropriate for its intended use and as a quality control material when demonstrating that specifications are met, ultimately reducing public health risks that may be associated with these products.

Major Accomplishments

• More than 20 natural-matrix SRMs have been produced with more in progress.
• Analytical methods have been developed for the measurement of citrus alkaloids, flavonoids, catechins, phytosterols, xanthines, and organic acids.
• Certificates of Analysis for these materials can be found here or by clicking the SRM numbers in the list to the right.

Additional Technical Details

In most cases, these SRMs are provided as suites of materials (plant, extract, finished product) that represent different analytical challenges. The constituents for which values are assigned are also listed. The constituents in all of these materials have been determined by multiple independent methods with measurements performed by NIST and collaborating laboratories. The methods utilized different sample extraction and cleanup steps in addition to different instrumental analytical techniques and approaches to quantification. These materials are provided primarily for use in method development and as control materials to support the measurement of these constituents in other similar products. 

Suites of materials based on black cohosh, soy, kudzu, and red clover are currently in progress.

GOALS

• Increase the types and availability of botanical dietary supplement SRMs to meet the needs of analytical laboratories, manufacturers, and regulators
• Develop methods of analysis for these materials
• Enable the establishment of a link to label information on botanical dietary supplements
• Provide calibration solutions for selected constituents in the botanical products

Associated Product(s)

SRMs

• 3246 Ginkgo biloba (Leaves)
• 3247 Ginkgo biloba Extract
• 3248 Ginkgo-Containing Tablets
• 3249 Ginkgo Dietary Supplement Suite
• 3250 Serenoa repens (Fruit)
• 3251 Serenoa repens Extract
• 3254 Camellia sinensis (Green Tea Leaves)
• 3255 Camellia sinensis (Green Tea) Extract
• 3256 Green Tea-Containing Solid Oral Dosage Form
• 3257 Catechin Calibration Solutions
• 3258 Bitter Orange (Fruit)
• 3259 Bitter Orange Extract
• 3260 Bitter Orange-Containing Solid Oral Dosage Form
• 3261 Bitter Orange Dietary Supplement Suite
• 3262 Hypericum perforatum L. (St. John's Wort) Aerial Parts - in progress
• 3263 Hypericum perforatum L. (St. John's Wort) CO2 Extract - in progress
• 3264 Hypericum perforatum L. (St. John's Wort) Methanol Extract - in progress
• 3265 Hypericum perforatum L. (St. John's Wort) Solid Oral Dosage Form - in progress
• 3274 Botanical Oils Containing Omega-3 and Omega-6 Fatty Acids (Flax, Borage, Evening Primrose, Perilla)
• 3275 Fish Oils Containing Omega-3 and Omega-6 Fatty Acids
• 3278 Tocopherols in Edible Oils
• 3281 Cranberry (Fruit)
• 3282 Low-Calorie Cranberry Juice Cocktail
• 3283 Cranberry Extract
• 3284 Cranberry-Containing Solid Oral Dosage Form
• 3285 Mixed Berry-Containing Solid Oral Dosage Form
• 3286 Organic Acids Calibration Solution
• 3287 Blueberry (Fruit)
• 3291 Bilberry Extract