What Is CBD and How Is It Produced?
Over the past few years, cannabidiol, better known as CBD, has become the holy grail of the unorthodox treatment modalities for the management of a number of ailments. Since it is federally categorized as a schedule 1 drug, science is still at the early stages, trying to unravel many mysteries surrounding CBD.
So what basically is CBD? How is it obtained? Where does it come from? What is the best method for extracting CBD? These questions have plagued the minds of many. We are about to delve into the secret world of CBD. Stay with us!
What is CBD?
Cannabidiol is one of the many chemical ingredients extracted from Cannabis sativa, the cannabis plant or the hemp plant. It is the same plant from which tetrahydrocannabinol (THC) is obtained, a psychoactive component of the hemp plant that induces a “high” state. What makes CBD stand out is the fact that it lacks the psychoactive properties associated with THC.
CBD works by interacting with the cannabinoid receptors located in the central and peripheral nervous system of the body. These receptors affect various physiological processes of the body, such as pain modulation, metabolism, appetite, memory, movements, and various cognitive functions.
Owing to a range of its therapeutic properties, CBD has drawn the attention of the medical community. As you read this article, researchers are working to discover the mechanisms by which CBD exerts its beneficial effects in alleviating pain, inflammation, muscle spasms, anxiety, and other problems.
CBD: Raw to Refined
The cannabis plant transcends through the following stages to become CBD.
- Cultivation and harvesting
- Solvent extraction
- Non-solvent extraction
1. Cultivation and Harvesting
The first step is cultivating and harvesting the cannabis plant varieties that have the highest concentration of CBD and the lowest amount of THC. The most commonly planted species of cannabis plant family for obtaining CBD is Cannabis sativa. The highest percentage of CBD is known to be concentrated in the flowering buds, called trichomes, of the female cannabis plant.
Once the plant has been harvested, the process of extraction of CBD from the plant starts. Various extraction methods are employed to isolate CBD from the plant. The end product not only depends on the quality of the plant but also on the method of extraction that is used.
Each extraction technique has its own set of pros and cons. Broadly speaking, there are two types of extraction methods.
- Solvent-based extraction methods
- Non-solvent techniques
Solvent-based Extraction Methods
The basic principle behind these methods is that a solvent is used which dissolves the CBD present in the plant. The solvent is then separated and CBD in obtained in concentrated form. On the industrial scale, 3 types of solvents are used for CBD extraction.
- Petroleum-based solvents
- Ethyl alcohol/ethanol
- Carbon dioxide, CO2
In addition to these solvents, olive oil can also be used to extract CBD from hemp oil but this method is not only time time-consuming but also, costly and effective for small-scale home extraction only.
A. Petroleum-based solvents
Butane is the most commonly used petroleum solvent for extracting CBD from the hemp plant. In this method, the crushed buds of the cannabis plant are placed inside a tube. One end of the tube is fitted with a screen that is meant to filter out all the liquids but not the solid particles.
The mixture of butane and soaked ground plant parts is introduced through the other end of the tube. Butane extracts all the CBD from the plant and trickles through the screen into a container. Butane is then either evaporated by heating or by vacuuming. The extract thus obtained can either be used as such or can be purified further via chromatography.
Propane can also be used to extract CBD. Propane-butane mixtures have also been used at commercial scale.
- This method is suitable for large scale as well as small-scale extraction of CBD.
- It is a cost-effective method and takes less time.
- Oil-based solvents are combustible by nature.
- The toxic residues like butane and propane can contaminate the extract, making it unfit for human ingestion.
B. Ethanol extraction
Since the solvent is alcohol based, ethanol extraction of CBD is a topic of extensive debate. The technique is quite similar to that with oil-based solvents. The ground cannabis plant is soaked in ethanol for a long time (longer than oil-based solvents) and the solute is then filtered. Ethanol is then separated.
- Ethanol can also be used for large-scale as well as small-scale CBD isolation.
- Unlike oil-based solvents, this method does not require high temperatures for solvent separation.
- It is a time-consuming process.
- The method requires a lot of precision to completely remove ethanol from the extracts and even then, traces of it may remain in the extract.
C. Carbon dioxide extraction
It is a rather sophisticated technique. Specialized equipment is used to convert carbon dioxide from its natural gaseous form into a liquid solvent state by compressing and condensing it. Liquid carbon dioxide is then changed into a “supercritical” form by the rapid increase in temperature and pressure.
Supercritical carbon dioxide has a dual properties-the density of liquid and attributes of a gas. Hence, in liquid form, it extracts CBD from the plant while the gas state does not require any other special procedure and simply evaporates off.
- It is the most eco-friendly method.
- It is the most dependable procedure for obtaining the purest form of CBD.
- The risk of contamination is quite low for this technique.
- It requires special equipment.
- It is not meant for large-scale extraction.
Non-Solvent Extraction Methods
Although rather outdated, non-solvent extraction techniques are still exercised at various levels for the purpose of extraction of CBD.
- CBD Isolates: CBD can be isolated by adding pentane to already processed cannabinoid oil and then alternatively heating and cooling it several times. A vacuum pump is then used to insert the mixture into pre-formed crystals.
- Dry Sifting: In this method, the trichomes of the cannabis plant are subjected to ultrafiltration which separates the CBD rich particles.
- Rosin Technique: In this technique, large presses squeeze the oil out of the cannabis plant.
The commonly used methods for further purifying the CBD extracts to remove the contaminants include
- Reversed Phase Chromatography: In this method, various adsorbents are used to remove impurities. Since different ingredients in a mixture have a different rate of attraction for the adsorbent, some particles are adsorbed more quickly, leaving others behind. This method can separate THC from CBD.
- Winterization: In this method, the CBD extracts are re-dissolved in a higher volume of ethanol and then frozen for at least 24 hours. The contaminants are then filtered out and ethanol is vaporized again by heating. This process removes fats, waxes, and lipids from the CBD extracts.
CBD is the Future
To cut through the clutter, CBD has emerged as a promising new drug for the treatment of various afflictions where conventional therapies have been exhausted without any significant results. Rigorous research needs to be carried out to find out full therapeutic potential of CBD. There is also an imminent need to develop large-scale extraction and refinement methods that can help harness the miracle of CBD.