by Claudia S. Copeland, Ph.D.
Cannabis is shedding its outlaw status and ascending to its rightful place as a medicinal wunderplant. From cancer and epilepsy to chronic pain and anxiety, the range of medical conditions that can be helped by cannabis is incredibly broad. One reason for this broad-spectrum efficacy is that nestled within its beautiful green leaves and buds are more than 100 compounds with medicinal potential. Called cannabinoids, each of these compounds has its own unique profile of effects on the human body.
What Are Cannabinoids?
The most famous of the cannabinoids is Δ9-tetrahydrocannabinol, or THC. This cannabinoid is responsible for the psychoactive effects of marijuana, but it also is extremely effective as an anti-nausea agent (particularly for the nausea induced by chemotherapy) and shows promise for a number of other conditions, including as a protective agent against aging-related cognitive decline. The second most well-known cannabinoid, cannabidiol or CBD, has also been shown to act as a neuroprotective agent through its anti-inflammatory and antioxidant properties, an anti-epileptic, an antipsychotic, and a potent anxiolytic. Other cannabinoids, found at lower concentrations in cannabis plants, have also shown medicinal potential for central nervous system disorders. These include cannabigerol (CBG), Δ9-tetrahydrocannabivarin (Δ9-THCV) and cannabidivarin (CBDV). In addition to the cannabinoids that naturally occur in plants, known as phytocannabinoids, a number of synthetic cannabinoids — compounds that bind to cannabinoid receptors but are not present in plants — have been created in the lab. The synthetic cannabinoid WIN 55,212-2, along with other lab-made cannabinoids, has shown promise as an anticancer agent.
Obtaining Cannabinoids from Plant Material
If you are working with synthetic cannabinoids, you will naturally start with a pure sample containing only the cannabinoid you are interested in. If, however, you want to isolate specific cannabinoids from a plant — or non-cannabinoid compounds found in cannabis, including antioxidant polyphenols — you will need to purify them in order to separate them from the other cannabinoids and plant matter. One way to accomplish this is with fractional distillation, which takes advantage of the different boiling temperatures of different chemicals. Essentially, you begin by evaporating and condensing whatever boils at a low temperature (if it’s room temperature, you can use ice to facilitate condensation), then after collecting that fraction, raise the temperature a bit, and collect whatever boils at that higher temperature, and so forth. What you will end up with is a collection of “fractions” representing chemicals with different boiling points. Of the more than 100 cannabinoids found in the cannabis plant, some can have very similar boiling points, so for highly pure extraction of a particular cannabinoid, an advanced automated fractionation system is recommended.
Cannabinoids and Heat
One important factor in cannabinoid processing is heat. Depending on your objective, you will need to either protect your sample from heat or apply heat to your sample. It is well-known among those seeking popular cannabis effects that a sample must be heated — either at the point of consumption (in the case of smoking or vaporizing) or during processing (in the case of edible preparations). This is because most of the THC and CBD in the raw cannabis plant are present in acidified forms — THC-acid-A and cannabidiolic acid — that do not exert the desired bioactivity. These forms must undergo a process called decarboxylation in order to become active, and that process is driven by heat.
Of course, heat also causes many other chemical reactions, including ones that could destroy the cannabinoid you’re after. For initial processing steps and protecting the desired compound from degradation after it is purified, it is important to research the particular compound you are interested in and how it interacts with heat.
pH and Oxidative Stress
In addition to heat, two other major factors can cause chemical reactions that change the nature of your cannabinoid sample during processing. One is pH. Cannabinoids, like all chemicals, will tend to change to acidic forms in a low-pH environment and to basic forms in a high-pH environment. When processing cannabinoids, it is important to research the ideal pH for the cannabinoids you are interested in and then fastidiously monitor and maintain that pH. You can take steps to protect your processed cannabinoids from acidic conditions using a protective nanoemulsion.
Another important factor is oxidative stress. Oxygen is a powerful chemical, but it is both friend and foe. While multicellular life would not have evolved on Earth without the energy provided by oxygen, that same energy can be extremely destructive if not harnessed and controlled. (Oxidation causes cars to rust, butter to go rancid and human cells to become cancerous. Oxidative damage is, in fact, a central factor in aging — making oxygen an element that both gives and takes away life itself.) With regard to cannabinoids, oxidation can transform THC into CBN, a less psychoactive cannabinol, and can degrade other cannabinoids as well. Encasing cannabinoids in a protective polymer matrix can help to protect them from oxidative degradation. Nanoemulsions can also be used to protect against oxidative damage, and using an antioxidant with a nanoemulsion can provide further protection.
Cannabinoids, Solubility and Bioavailability
Another important function provided by a nanoemulsion is that of increasing the water solubility — and therefore the bioavailability — of cannabinoids. Cannabinoids, including CBD and THC, are hydrophobic (fat soluble), which means that they do not readily dissolve in water. This problem goes far beyond annoyance when trying to create cannabinoid-infused beverages. Since cannabinoids are primarily of interest as medicinal compounds, it is highly important that they be absorbed by the body after they are ingested. Compounds that are not water soluble will not disperse well in the water-based environment of the gastrointestinal tract and therefore will not be absorbed well. (In order for your body to use a substance, it must first be absorbed by the body. A substance that “passes right through you” will not have any medicinal effect.) This is perhaps the most important benefit provided by a nanoemulsion, which allows hydrophobic compounds like cannabinoids to be evenly dispersed in water, increasing their bioavailability by allowing them to be well-absorbed from the GI tract.
Flavor, Appearance and Other Considerations
If you are incorporating cannabinoids into an edible or drinkable form, your final processing step will be one of formulation. Concerns at this stage of processing include shelf life and aesthetic considerations as well as bioavailability. One of the best ways to optimize your final cannabinoid-infused product is to use a top-tier next-generation powder or a turnkey nanoemulsion. These products provide protection from pH extremes, oxidative degradation and heat, increasing shelf life. At the same time, they allow hydrophobic cannabinoids to disperse in water, which maximizes bioavailability. Because bioavailability is the endpoint of cannabinoid processing, this is not a step to omit. After all your hard work processing cannabinoids, make sure your final product is one that delivers maximal medicinal power — both when it’s freshly made and after it’s been transported to store shelves and sold to your valued customers.