On this page: Reference standards | Quantified by input | Good agricultural and collection practices (GACP) | Adulteration or substitution of herbal substances | Identification of herbal materials | Samples of unmilled plants
Reference standards
If an active or marker compound is identified and no commercially available primary standard is available, a suitably controlled and characterised reference material of that compound should be obtained from external sources.
Quantified by input
Quantified by input (QBI) is applicable to listed complementary medicines only. Medicinal cannabis products, once registered on the ARTG will contain a restricted ingredient/component and therefore quantitative testing of the active ingredient in the finished product would be required.
QBI is also not applicable to unapproved medicinal cannabis product dosage forms made available under the access pathways.
Good agricultural and collection practices (GACP)
Statements within this Annex relating to Good Agricultural and Collection Practices (GACP) are not mandatory.
Alternative methods of assuring the suitability and quality of herbal starting materials are permissible. It is recommended that GACP are considered during supplier qualification, as GACP may assist in influencing routine sampling and testing programs for herbal starting materials.
Some other countries may seek to import material specifically compliant with GACP- it is a matter for the exporter to determine relevant country import requirements.
The recommendations regarding GACP apply to manufacturers involved in the cultivation of herbal starting materials (herbs) only.
The grower/supplier of the medicinal cannabis plant or the API substance manufacturer should provide a written GACP declaration and the supporting documentation to the manufacturer of the finished product. This will be assessed as part of supplier qualification.
Adulteration or substitution of herbal substances
Manufacturers should assess the range of herbal substances used in order to determine whether specific herbal substance is at risk of adulteration or substitution. Potential risk factors include:
- materials with high intrinsic value that may be substituted or 'bulked-out' with other materials, i.e. cheap plant material, fillers
- highly active compounds including Schedule 8 medicines
- ingredients that may be adulterated with medicinal substances included in schedules 3, 4 and 8 of the Poisons Standard, e.g. steroids, diuretics, stimulants or medicines used in the treatment of erectile dysfunction
- herbal materials that are difficult to distinguish microscopically, e.g. milled or powdered materials and plant parts that have very similar microscopic appearance
- materials from new sources especially in circumstances where the reputation of reliability of the supplier is not known
- large offers of herbal materials that are generally only available in limited quantities
- out-of-range prices for materials
The justification and application of additional testing should follow basic risk management principles.
Identification of herbal materials
The TGA has published guidance regarding the requirements for Identification of herbal materials and extracts.
Samples of unmilled plants
Manufacturers performing the identity testing of herbal materials are required to hold appropriate certified/authenticated reference samples for the herbal materials used.
Reference samples should be traceable back to a suitable primary reference material. Where powdered materials are used in the manufacture of an API or product, the manufacturer performing the testing is expected to hold an appropriate certified reference material of unmilled plant. This is due to the inherent difficulties and risks associated with the identification of powdered plants.