The levels of three Cannabinoids- Cannabidol, (CBD) Delta-9- Tetrahydro Cannabinol (THC) and Cannabinol (CBN) in 24 samples from the various regions in the country have been determined using gas liquid chromatographic method. The levels of THC (the biological active cannabinoid) in the samples ranged from 0.039-1.549 per cent w/w with coefficient of variation of 2.45 per cent. Classification according to the phenotype ratio method put the Ghanaian samples into phenotype I. the content of CBD ranged from 0.116-0.620 per cent w/w whilst the levels of CBN fell between 0.049-1.069 per cent w/w.
The levels of Cannabinoids in Cannabis sativa (L) are known to be influenced by factors such as ecology, stages of development of the plant, genetics and seasonal changes 1-2. Various attempts have been made to classify Cannabis according to the geographical origin but not with much success (3-6). Difficulties encountered in such classification exercises have been attributed partly to the fact that there are a whole range of unauthenticated samples of Cannabis obtainable from unauthorized cultivations from all corners of the world. The problem is made more difficult by the unstable nature of Cannabis samples on storage. These difficulties in classification are not encountered with Opium where cultivation in most parts of the world is authorized and the Opium where samples tend to be more stable on storage than Cannabis.
Despite the above mentioned difficulties, some efforts have been made to classify various samples of Cannabis using other characteristics of the plant. Content of Cannabinoid acid sand phenols in Cannabis has been used to classify the plant into fibre and drug types7. Fetterman et al8 recently also suggested another way of classifying Cannabis into chemical phenotypes: phenotype ratio= (% (-) Δ9 – trans -tetrahydro-cannabinol +% Cannabinol): %Cannabinol.
According to this method, Cannabis samples with phenotype ratios greater than 1.0 are classified as phenotype I. the phenotype I is regarded as biologically active and samples with ratios less than 1.0 are classified into phenotype II or the fiber-type Cannabis.
This method of classification is used in classifying 24 samples of Cannabis randomly selected from Police seizures from the various regions in Ghana. Up-to-date no data on quantitative levels of Cannabinoid in Cannabis samples as found in Ghana have been reported. With complexing problems in classifying the various samples as found in many parts of the world are systematically studied. The present report is part of a programme initiated in our Laboratory to examine systematically samples of Cannabis in Ghana.
© The Author(s) 1974. Published by the Pharmaceutical Society of Ghana (PSGH). This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.