Microbiological Quality of Herbal Substances

The United States Pharmacopeia (USP) Botanical Dietary Supplements and Herbal Medicines (BDSHM) Expert Committee is working on a new USP General Chapter <1114> Ensuring Microbiological Quality of Articles of Botanical Origin.

Pharmacopoeial Standards Needed

Herbal substances generally have a higher bioburden compared to synthetic or purified materials. According to the USP BDSHM Expert Committee, this presents "particular challenges as undesirable microorganisms may be carried over to botanical dietary supplement products". In addition, spores and mycotoxins (e.g. Aflatoxins, Ochratoxin, Vomitoxin) may also be present and these are more difficult to eliminate, once they are present in the herbal material. Pharrmacopoeial provisions and Good Manufacturing Practices (GMPs) require the control and prevention of microbiological contamination of raw materials and finished products. Decontamination technologies (e.g. by using ozone, irradiation, etc.) applied to control the bioburden can have an impact on the quality of the herbal drug / substances (e.g. degradation of active ingredients). The proposed USP chapter will therefore provide information on "practices to prevent" as well as "methods to treat" microbial contamination of articles of botanical origin (ABOs) as well as considerations for maintaining quality.

The European Pharmacopoeia (Ph. Eur.), for example, contains a "special provision for herbal substances for oral use" (Ph. Eur. 5.1.4) and provides different categories (Ph. Eur. 5.1.8 A, B, C) for microbiological requirements for herbal medicinal products and extracts for oral use (for example category B for herbal drugs, in case a pre-treatment for reducing microbiological contamination is possible).

Proposed Outline of USP <1114>

The following sections are proposed to be included in the General Chapter

• Introduction
• Pharmacopeial microbiological quality and regulatory compliance
• Practices for preventing microbial contamination
• Methods for reduction of microbial contamination
• Validation of microbial control measures
• References

USP is requesting early input from stakeholders (e.g. suppliers of botanical ingredients, dietary supplement manufacturers, testing laboratories) on this newly proposed informational General Chapter until 29 May 2022. The chapter is then planned to be published for comment in Pharmacopeial Forum PF 48(6) [Nov.- Dec. 2022].

More information is available at USP´s Compendial Notices website in New General Chapter Prospectus: <1114> Ensuring Microbiological Quality of Articles of Botanical Origin General Chapter Prospectus.