05.03.2024 | LOGFILE Feature 5/2024

Tests in the New Ph. Eur. Monograph on Cannabis Flower

Tests in the New Ph. Eur. Monograph on Cannabis Flower

5 min. reading time | by Sabine Paris

The monograph on Cannabis flower (3028) has been published in Ph. Eur. Supplement 11.5 in January 2024, with an implementation date of 1 July 2024. All member states of the European Pharmacopoeia are required to replace their national monographs with this new Ph. Eur. Monograph.

Existing national monographs have been used in the preparation of this new monograph, e. g. the monographs of Germany, Denmark, the Netherlands and Switzerland.

The Ph. Eur. monograph on Cannabis flower covers the herbal drug used as a raw material for the production of extracts, or prescribed as is, to be taken by patients by inhalation or oral administration (i.e. prescribed to patients as a medicinal product).

The European Directorate for the Quality of Medicines and HealthCare (EDQM) presented key points and background information in a webinar on 14 December 2023.

This feature summarises the necessary tests required by the monograph.

Tests Cannabis
Monograph (3028)


Comment/Background Information

Total CBN: sum of
cannabinol (CBN), and cannabinolic acid (CBNA) expressed as CBN

1.0 %

Contents of more than 1.0 % of CBN indicate significant degradation of the herbal drug.

Liquid chromatography (UV detection) with an octadecylsilyl silica gel column is the method of choice.

Foreign Matter

2.0 %

Seeds and leaves longer than 10 mm are considered foreign matter.

Loss on Drying

12.0 %

It is necessary to perform this test at low temperature (40 °C) and under 'medium vacuum' to minimise evaporation of non-water volatiles (e.g. essential oil/terpenes).


0.2 ppm

If the herbal drug is not used as a medicinal product, the same limits as in the general monograph Herbal Drugs (1433) apply.

Otherwise, the listed limits derived from ICH Q3D for Class I elements based on the permissible daily inhalation exposure apply.


1.0 ppm


5.0 ppm


0.1 ppm

Figure 1                 Test of Ph. Eur. Cannabis flower monograph


A specification for moulds is not included in the monograph but this is covered in the general chapter on foreign matter (2.8.2) – ‘other foreign elements‘. A risk assesment shall be carried out for the control of moulds. The sampling procedure and the expected appearance of the herbal drug are defined. Mould control is also covered by GACP (Good Agricultural and Collection Practice).

Other applicable tests according to the general monograph Herbal Drugs (1433) are:

Other tests from the
general monograph Herbal Drugs (1433)

Comment/Background Information


If cultivation takes place in a closed environment where contamination with pesticides is not possible, the manufacturer may justify not testing for pesticides by the design and agricultural method of production. This approach must be agreed with the competent authority.

Aflatoxin B1

According to the general chapter Determination of aflatoxin B1 in herbal drugs (2.8.18) herbal drugs must not contain more than 2 µg/kg of aflatoxin B1.

Microbial contamination

If the herbal drug is used as a medicinal product, the limits in Ph. Eur. chapters 5.1.8 Microbiological quality of herbal medicinal products for oral use and
extracts used in their preparation
and 5.1.4 Microbiological quality of non-sterile pharmaceutical preparations and substances for pharmaceutical use apply.

Figure 2                 Other test from the monograph Herbal Drugs (1433)


Test for other aflatoxins than aflatoxin B1 are not included in the monograph because Cannabis flower does not present a particularly high risk of being affected by fungal infections. Cannabis flos does not have a particularly high sugar content.

A test for total ash is not included in the monograph because mineral contamination of Cannabis flower is expected to be very low.


Ph. Eur. Monograph on Cannabis flower (3028)

EDQM-Webinar: The new Ph. Eur. Cannabis flower monograph (3028), Thu, Dec 14, 2023

Sabine Paris


Sabine Paris, PhD
Senior GMP Expert, Pharmacist
E-Mail: sabine.paris@gmp-publishing.com

Cannabis GMP Wiki – Explore the GMP World of Medicinal Cannabis!

Cannabis GMP Wiki – Explore the GMP World of Medicinal Cannabis!

Be the First to Benefit from Cannabis GMP Wiki!

You will Get:

  • a professional knowledge database.
  • comprehensive insights and practical tools.
  • compiled GMP and GACP Aspects you need to know when producing Medicinal Cannabis.

Current Status and Timeline:

  • The Wiki structure is developed.
  • First content on quality management systems is already incorporated.
  • Launch is planned for June/July 2024.

> More information and order