An Overview of Galenic Preparation Methods for Medicinal Cannabis

In recent years, the Cannabis plant (Cannabis sativa L.) has been rediscovered as a source of new medicines around the world. Despite the fact that a number of registered medicines have been developed on the basis of purified cannabis components, there is a rapid increasing acceptance and use of cannabis in its herbal form. Licensed producers of high quality cannabis plants now operate in various countries including The Netherlands, Canada, Israel, and Australia, and in many US states. The legal availability of cannabis flowers allows to prescribe and prepare different cannabis galenic preparations by pharmacists. It is believed that synergy between cannabis components, known as “entourage effect”, may be responsible for the superior effects of using herbal cannabis versus isolated compounds. So far, only a few cannabis components have been properly characterized for their therapeutic potential, making it unclear which of the isolated compounds should be further developed into registered medicines. Until such products become available, simple and accessible galenic preparations from the cannabis plant could play an important role. In cannabis, phytochemical and pharmacological attention has been attributed mainly to four major cannabinoids (Δ9- tetrahydrocannabinol, cannabidiol, cannabigerol and cannabichromene) and to terpene components. This means a basic knowledge of these compounds and their bioavailability in different administration forms is useful for producers as well as prescribers of galenic preparations. This work will outline the most important aspects of cannabinoids and terpenes, and their behaviors during preparation and use of various administration forms including vaporizing, cannabis oils and extracts, tea, and skin creams.