Date Time: Dec 10th, 2020 11:00 AM Pacific Time
Dr. Nandu Sarma presented at the final CANN journal club meeting of 2020. The meeting was hosted by Julia Bramante, Chair of the Cannabis Chemistry Subdivision of ACS. They know each other from AOAC cannabis working groups. Sarma presented his Journal of Natural Products paper at the Fall 2020 ACS conference.
A pharmacognosist by training, when he began initially at USP in 2006, cannabis was nowhere in sight. The focus was on developing monographs and admission criteria for dietary supplements, there was an emphasis on safety, contamination, labeling, and liver damage. USP’s mission is “To improve global health through public standards and related programs that help ensure the quality, safety and benefit of medicines and foods.” The United States Pharmacopeia is 200 years old, started in 1820 by 11 founding members, and today they have over 900 staff and more than 1,000 expert volunteers. They have written over 5,900 monographs, covering pharmaceuticals, food ingredients, herbal medicines, and dietary supplements. USP standards are used in more than 140 countries, and legally recognized in 39.
This paper is not an official USP monograph due to the US federal regulatory status of cannabis inflorescence. That is why it is published in a peer-reviewed journal instead of as an official USP monograph. So, it is technically a USP cannabis expert panel work on the plant material – cannabis inflorescence, published in the Journal of Natural Products. There is still a big public health rationale for establishing quality attributes for cannabis because these products are used for medical conditions by a vulnerable population. Additionally, standardized quality materials are needed for clinical studies to occur. USP initiatives are intended for reduction of harm from products and to enable systematic clinical studies.
The paper provides hierarchical nomenclature, methods for identification of micro and macroscopic characteristics, limits for contaminants, appropriate analytical methods, and acceptance criteria. HPTLC was used to distinguish 11 cannabinoids. Although there are some closely eluting peaks, elution before and after decarboxylation provides clear indication of the major cannabinoids present. The cannabinoid peak elution order on HPLC and GC are presented with chromatographic conditions. Some instability was seen with cannabinoid carboxylic acids, so now the USP reference standard for the 5-part Cannabinoid Acids mixture contains trimethylamine as a stabilizer. In addition to metals, pesticides, and microbial requirements, additional sections address proper sampling, water activity, foreign matter, total ash and acid-insoluble ash, and packaging and storage requirements.
Beyond this publication, work is underway to develop quality attributes for specifically hemp, as well as hemp and cannabis extracts. The extract monographs will differentiate and define types of extracts such as distillate, isolate, and broad spectrum. This is important to establish considering some extracts are decarboxylated and others are not. Also, to be introduced is the importance and acceptance criteria of residual solvent tests, which is unique to concentrates. So, although the USP does not officially recognize the monograph because it is cannabis, perhaps making one for hemp or CBD will be officially recognized. Either way, it is still important to establish and publish standards for identification of a manufactured and consumed substance.