You must positively identify the cannabis plant used in the manufacture of medicinal cannabis products and differentiate it from potential adulterants and substitutes using each of the following identification methods (section 10 of TGO 93):
- macroscopic examination
- microscopic examination
- chromatographic procedures
These identification methods must be suitably validated and performed on every batch of the cannabis plant.
TGA guidance Identification of herbal materials and extracts relates to the identification of plant materials, such as cannabis plant, that do not have a monograph in a pharmacopoeia recognised by the TGA. This guidance specifies that the macroscopic, microscopic, and chemical characteristics of the plant should be compared against either:
- an authenticated reference specimen
OR
- the descriptions given in an authoritative literature source such as:
- the United Nations Office of Drugs and Crime website: Recommended methods for the identification and analysis of cannabis and cannabis products
- the American Herbal Pharmacopoeia monograph Cannabis inflorescence
Further guidance on identification testing is given in United States Pharmacopeia-National Formulary General Chapter <563> Identification of articles of botanical origin.
Chromatographic procedures
Chromatographic procedures are chemical tests that determine whether the characteristic chemical constituents of the plant are present in the plant.
Examples of chromatographic procedures include:
- high-performance liquid chromatography
- thin-layer chromatography
- gas chromatography
Tests may involve one or more chromatographic procedures. For example, the British Pharmacopoeia monograph for Holy Basil Leaf (the dried leaves of Ocimum tenuiflorum) stipulates the use of macroscopic and microscopic examination as well as two thin-layer chromatography test procedures for the identification of the plant.
Chemical constituents of cannabis plant
Recognised chemical constituents of the cannabis plant include cannabinoids, such as tetrahydrocannabinols, and terpenes.
Examples of tetrahydrocannabinols include:
- delta-9-tetrahydrocannabinol (also commonly referred to as tetrahydrocannabinol, delta-9-THC, or THC)
- tetrahydrocannabinolic acid (THC-acid)
- delta-8-THC
- tetrahydrocannabivarin (THCV or THV)
- 11-hydroxy-delta-9-THC
Examples of other cannabinoids include:
- cannabidiol (CBD)
- cannabidiolic acid (CBD-acid)
- cannabichromene (CBC)
- cannabinol (CBN)
Examples of terpenes include:
- beta-caryophyllene
- geraniol
- alpha-humulene
- limonene
- linalool
- myrcene
Some cannabinoids such as THC and CBD are unique to the Cannabis genus.