Cannabis, from plant to pill

The therapeutic application of cannabis is attracting substantial public and clinical interest. The cannabis plant has been described as a veritable 'treasure trove', producing more than 100 different cannabinoids, although the focus to date has been on the psychoactive molecule delta-9-tetraydrocannabinol (THC) and cannabidiol (CBD). Other numerous secondary metabolites of cannabis, the terpenes, some of which share the common intermediary geranyl diphosphate (GPP) with the cannabinoids, are hypothesized to contribute synergistically to their therapeutic benefits, an attribute that has been described as the 'entourage effect'. The effective delivery of such a complex multicomponent pharmaceutical relies upon the stable genetic background and standardized growth of the plant material, particularly if the raw botanical product in the form of the dried pistillate inflorescence (flos) is the source. Following supercritical CO₂ extraction of the inflorescence (and possibly bracts), the secondary metabolites can be blended to provide a specific ratio of major cannabinoids (THC : CBD) or individual cannabinoids can be isolated, purified and supplied as the pharmaceutical. Intensive breeding strategies will provide novel cultivars of cannabis possessing elevated levels of specific cannabinoids or other secondary metabolites.