Gabriel I. Giancaspro

Safety of green tea extracts : a systematic review by the US Pharmacopeia.

Green tea [Camellia sinensis (L.) Kuntze] is the fourth most commonly used dietary supplement in the US. Recently, regulatory agencies in France and Spain suspended market authorization of a weight-loss product containing green tea extract because of hepatotoxicity concerns. This was followed by publication of adverse event case reports involving green tea products. In response, the US Pharmacopeia (USP) Dietary Supplement Information Expert Committee (DSI EC) systematically reviewed the safety information for green tea products in order to re-evaluate the current safety class to which these products are assigned. DSI EC searched PubMed (January 1966–June 2007) and EMBASE (January 1988–June 2007) for clinical case reports and animal pharmacological or toxicological information. Reports were also obtained from a diverse range of other sources, including published reviews, the US FDA MedWatch programme, USP’s MEDMARX® adverse event reporting system, the Australian Therapeutic Goods Administration, the UK Medicines and Healthcare products Regulatory Agency, and Health Canada’s Canadian Adverse Drug Reaction Monitoring Program. Case reports pertaining to liver damage were evaluated according to the Naranjo causality algorithm scale. In addition, the Committee analysed information concerning historical use, regulatory status, and current extent of use of green tea products. A total of 216 case reports on green tea products were analysed, including 34 reports concerning liver damage. Twenty-seven reports pertaining to liver damage were categorized as possible causality and seven as probable causality. Clinical pharmacokinetic and animal toxicological information indicated that consumption of green tea concentrated extracts on an empty stomach is more likely to lead to adverse effects than consumption in the fed state. Based on this safety review, the DSI EC determined that when dietary supplement products containing green tea extracts are used and formulated appropriately the Committee is unaware of significant safety issues that would prohibit monograph development, provided a caution statement is included in the labelling section. Following this decision, USP’s DSI ECs may develop monographs for green tea extracts, and USP may offer its verification programmes related to that dietary ingredient.

The state of dietary supplement adverse event reporting in the United States

The Dietary Supplements Information Expert Committee (DSI‐EC; the Committee) of the United States Pharmacopeial Convention (USP) reviews safety profiles of dietary supplements before development of USP–National Formulary (USP–NF) quality monographs. Because the veracity of dietary supplement adverse event reports (DS AERs) directly affects DSI‐EC safety reviews, the Committee reviewed the current status of DS AER reporting in the US.

United States pharmacopeia safety evaluation of spirulina.

The Dietary Supplements Information Expert Committee (DSI-EC) of the United States Pharmacopeial Convention (USP) reviews the safety of dietary supplements and dietary supplement ingredients for the purpose of determining whether they should be admitted as quality monographs into the United States Pharmacopeia and National Formulary (USP–NF). The United States Food and Drug Administration (FDA) has enforcement authority to pursue a misbranding action in those instances where a dietary supplement product indicates that it conforms to USP standards but fails to so conform. Recently DSI-EC undertook a safety evaluation of spirulina, a widely used dietary ingredient. DSI-EC reviewed information from human clinical trials, animal studies, and regulatory and pharmacopeial sources and analyzed 31 adverse event reports regarding spirulina to assess potential health concerns. At the conclusion of this review, DSI-EC assigned a Class A safety rating for Spirulina maxima and S. platensis, thereby permitting the admission of quality monographs for these dietary supplement ingredients in USP–NF. DSI-EC continually monitors reports concerning the safety of dietary supplements and dietary supplement ingredients for which USP dietary supplement monographs are developed. The DSI-EC may revisit the safety classification of spirulina as new information on this dietary ingredient becomes available.

Dietary supplements quality analysis tools from the United States Pharmacopeia.

The United States Food and Drug Administration (FDA) issued the dietary supplement (DS) current good manufacturing practice (GMP) regulations in compliance with the mandate from the Dietary Supplements Health and Education Act (DSHEA), with the intention of protecting public health by ensuring the quality of DS. The GMP regulations require manufacturers to establish their own quality specifications for identity, purity, strength, composition, and absence of contaminants. Numerous FDA‐conducted GMP inspections found that the private specifications set by these manufacturers are often insufficient to ensure adequate quality of dietary ingredients and DS. Wider use of the public standards developed by the United States Pharmacopeial Convention (USP), in conjunction with GMP compliance, can help ensure quality and consistency of DS as they do for medicines. Public health protection could be enhanced by strengthening the GMP provisions to require conformance with relevant United States Pharmacopeia–National Formulary (USP–NF) standards, or in the absence of USP standards, other public compendial standards. Another serious concern is the presence of synthetic drugs and drug analogues in products marketed as DS. Use of the new USP General Chapter Adulteration of Dietary Supplements with Drugs and Drug Analogs <2251> may reduce the exposure of consumers to dangerous drugs disguised as DS.

Response to Teschke et al.

Dear Editor, The review by Teschke et al.1 reanalyzed a selected group of 22 spontaneous reports from regulatory agencies for the causal relationship between the use of black cohosh–containing products and hepatotoxicity and concluded that an “updated” Council for International Organizations of Medical Sciences (CIOMS) scale should replace the liver-unspecific Naranjo scale. The “update” referred to by the author is not originated by the CIOMS but includes the authors’ modifications to the scale. On the basis of their new approach, the authors conclude that causality for black cohosh– mediated liver damage is “unlikely or excluded.” We would like to draw attention to some of the fundamental flaws with the authors’ analysis:

Quality Specifications for Articles of Botanical Origin from the United States Pharmacopeia

BACKGROUND In order to define appropriate quality of botanical dietary supplements, botanical drugs, and herbal medicines, the United States Pharmacopeia (USP) and the Herbal Medicines Compendium (HMC) contain science-based quality standards that include multiple interrelated tests to provide a full quality characterization for each article in terms of its identity, purity, and content. PURPOSE To provide a comprehensive description of the pharmacopeial tests and requirements for articles of botanical origin in the aforementioned compendia. Selective chromatographic procedures, such as high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC), are used as Identification tests in pharmacopeial monographs to detect species substitution or other confounders. HPLC quantitative tests are typically used to determine the content of key constituents, i.e., the total or individual amount of plant secondary metabolites that are considered bioactive constituents or analytical marker compounds. Purity specifications are typically set to limit the content of contaminants such as toxic elements, pesticides, and fungal toxins. Additional requirements highlight the importance of naming, definition, use of reference materials, and packaging/storage conditions. METHODS Technical requirements for each section of the monographs were illustrated with specific examples. Tests were performed on authentic samples using pharmacopeial reference standards. The chromatographic analytical procedures were validated to provide characteristic profiles for the identity and/or accurate determination of the content of quality markers. RESULTS The multiple tests included in each monograph complement each other to provide an appropriate pharmacopeial quality characterization for the botanicals used as herbal medicines and dietary supplements. The monographs provide detailed specifications for identity, content of bioactive constituents or quality markers, and limits of contaminants, adulterants, and potentially toxic substances. Additional requirements such as labeling and packaging further contribute to preserve the quality of these products. CONCLUSION Compliance with pharmacopeial specifications should be required to ensure the reliability of botanical articles used for health care purposes.

Challenges and Opportunities for Improving the Safety Assessment of Botanical Dietary Supplements: A United States Pharmacopeia Perspective

The United States Pharmacopeia (USP) is an independent, nonprofit, science‐based organization whose mission is to improve global health through public quality standards for dietary supplements, medicines, and food ingredients.1 Before developing standards for dietary supplement ingredients, the USP performs an “Admission Evaluation” (Figure 1), which includes an assessment to ascertain that an ingredient does not present a serious health risk.2 This article discusses the challenges encountered during the evaluation of botanicals and proposes possible solutions.