There is a rapidly growing market for therapeutic and medicinal products containing cannabinoids from Cannabis, driven in part by a growing acceptance of their therapeutic benefits, and by global regulatory change that allows more widespread use of both recreational and prescribed products. There are a number of known and established methods for preparation and concentration of extracts containing cannabinoids and other natural compounds from the plant material; however, in many cases these are still poorly developed and understood from a large scale industrial manufacturing perspective. Product composition preferences and preferred formulation options are also still very much in development.

This paper gives a review of the current state of the art for extraction and fractionation of Cannabis Sativa. One of the emerging methods of choice is extraction using supercritical fluid CO2 as it offers flexibility and selectivity in terms of the extract composition and is a low temperature solvent-free process that produces a high quality product. Here we present experimental data on the extraction of two New Zealand grown industrial hemp cultivars using supercritical CO2 and subcritical (liquid) propane. The effect of decarboxylation of the plant material on the yields and extract composition is also presented.