In October 2022, the European Pharmacopoeia (Ph. Eur.) published the initial draft of its new cannabis flower monograph, seeking feedback from the public. Following this public consultation period, the new cannabis flower monograph was published in Supplement 11.5 of the Ph. Eur. in January 2024, with the guidelines to be applicable in 39 countries, including the UK, from the 1st of July 2024.
So, what is the new Cannabis flos (flower) monograph and what does it mean for patients prescribed medical cannabis in the UK?
What is a monograph?
Pharmacopeial monographs are descriptions of medical preparations designed to identify the qualities of medicines and the quality standards required for each medicine. These monographs provide detailed parameters that are used to determine whether a given medicine meets key quality standards and can be legally marketed.
There are a number of pharmacopoeias in use by different countries around the world, though not every country has their own pharmacopoeia. In other cases, a country may adopt a monograph from a larger pharmacopoeia when its own pharmacopoeia does not cover the medicine in question. While the UK uses the British Pharmacopoeia, it may also adopt monographs from other sources, such as the European Pharmacopoeia.
The Ph. Eur. is now recognised in 39 countries across Europe. Reference to a single pharmacopoeia helps to ensure the continuity of standards between jurisdictions in the region.
Pharmacopoeias and medical cannabis
While medical cannabis is legal in several European countries, including the UK, this is the first medical cannabis monograph published in the Ph. Eur. The latest supplement (11.5) also includes a new monograph on cannabidiol (CBD).
Jurisdictions among the 39 countries that adopt monographs from the Ph. Eur. which have already published their monographs on cannabis flower, such as Denmark, the Netherlands, Germany, and Switzerland, will replace this with the new European monograph.
The Ph. Eu. Monograph on cannabis flower
The European Pharmacopoeia’s final monograph on Cannabis flower was published in January 2024. The pre-released version of the monograph was published in October 2023 and provides us with details about this new guidance. However, GMP-Compliance notes that several additional requirements have been added to the latest version.
The new monograph outlines the official definition of cannabis flower as well as production methods, identification processes, and microscopic examination to identify the cannabinoid content of the product. The monograph also defines limits on foreign matter, moisture content, and the presence of seeds and leaves, and includes updated labelling requirements.
What does the new Cannabis flower monograph say?
The European Pharmacopoeia monograph defines cannabis flower or Cannabis flow as:
“Dried, whole or fragmented, fully developed female inflorescence of Cannabis sativa L.”
The monograph continues: “If the herbal drug is to be prescribed to patients as a medicinal product, the measured contents of total tetrahydrocannabinol and total cannabidiol, respectively, do not deviate from the values stated on the label by more than ± 10 per cent.”
The monograph also outlines the cannabinoid content of THC-dominant type, THC/CBD-intermediate type, and CBD-dominant type cannabis flower. They are as follows:
THC-dominant type:
- Total Δ9-THC: minimum 5.0% (dried drug);
- Total CBD: maximum 1.0% (dried drug)
THC/CBD-intermediate type:
- Total Δ9-THC: minimum 1.0%
- Total CBD: minimum 1.0%
- total tetrahydrocannabinol / total cannabidiol ratio: 0.2 to
- 5.0 (dried drug).
CBD-dominant type:
- Total Δ9-THC: maximum 1.0%
- Total CBD: minimum 5.0%
Further notable guidance from the monograph concern:
Foreign matter should represent at most 2% of the preparation. Furthermore, if the cannabis flower is to be prescribed to patients as a medicinal product, “it does not contain any seeds and the whole herbal drug does not contain any leaves more than 1.0 cm in length.”
Loss on drying should be no more than 12.0%, which is increased from 10% in the draft version of the monograph.
Presence of heavy metals including arsenic (maximum 0.2 parts per million (ppm)), cadmium (maximum 1.0 ppm), lead (maximum 5.0 ppm), and mercury (maximum 5.0 ppm) if the herbal drug is to be prescribed to patients as a medicinal product.
What about the Ph. Eur.’s CBD monograph?
As we mentioned earlier, Supplement 11.5 also includes a monograph for cannabidiol (CBD). With the publication of this monograph, the Ph. Eur. states that “CBD is isolated from the Cannabis sativa L. plant.” In previous drafts of the monograph, it was stated simply that CBD is isolated from “natural sources”.
These guidelines, among others laid out in Supplement 11.5 of the European Pharmacopoeia, have now been accepted by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) and will be introduced from the 1st of July 2024. More information regarding Supplement 11.5 can be found here.
What does this mean for medical cannabis patients?
Over the last decade and a half, most countries across Europe have introduced laws legalising the medical use of cannabis. In this time, the number of medical cannabis patients in Europe has been consistently on the rise. Yet, quality standards and production rules have differed from country to country, making Europe something of a regulatory patchwork.
While patients shouldn’t notice any issues in the supply of medical cannabis products, it is hoped that the publication of the Ph. Eur.’s monograph on cannabis flower will provide quality standardisation and harmonisation across the 39 countries that accept it. This should help to limit the supply of substandard medical cannabis flower products in the UK.
Furthermore, official limitations on foreign matter permitted in cannabis flower mandate that products to be prescribed for medicinal purposes should contain no seeds. If implemented effectively, this should address the growing concern among patients in the UK who have received medical cannabis flower containing seeds.
Conclusions
The final publication of Supplement 11.5 of the European Pharmacopoeia provides a harmonised definition as well as standardisation in the production, content, and labelling of cannabis flower products. As the primary source of official quality standards for medicines and their ingredients in Europe, the contents of the monographs for cannabis flower and CBD will become mandatory on the same date in all participating states and should lead to better quality cannabis flower for people who take up prescriptions.
