What are Carrier Oils and How Do They Impact CBD?
Choosing the right CBD product isn’t as simple as walking into any store that sells it and buying whatever they’ve got on the shelf. When it comes to CBD, with or without THC, quality matters and not all products are created equal. Of particular importance is the use of carrier oil and the role it plays in cannabis extract or isolate nanoemulsion. Let’s explore this in greater detail below.
Why carrier oil?
There are three primary advantages to formulating cannabis isolates and extracts as nanoemulsions, a.k.a. nano-cannabinoids, which deliver a greater therapeutic effect. These advantages are as follows:
- Compatibility with liquid (easily mixed into beverages)
- Exceptionally high bioavailability (faster and more complete absorption)
- Long-term stability (multi-year shelf life)
While it’s certainly possible to produce a cannabis extract or isolate without the use of a carrier oil, the result will be poor bioavailability and instability. A quality and well-chosen carrier oil can help prevent these disadvantages. Here’s how.
Reduced droplet size = greater stability and bioavailability.
In order for nanoemulsions to be kinetically stable and bioavailable, they must feature small droplet sizes (<300 nm). Achieving the smallest droplet size requires similar viscosities of the dispersed phase (oil) and continuous phase (water).
Because the viscosity of cannabis extracts is typically much higher than that of water, the emulsions formed tend to feature a much larger droplet size. Adding a carrier oil can reduce this natural viscosity, facilitating the easier production of nanoemulsions with much smaller droplet sizes.
Prevention of Ostwald ripening = greater stability
Ostwald ripening is a destabilization process through which a variance in Laplace pressure causes the smaller oil droplets in a nanoemulsion to have higher local solubilities than the larger droplets. This results in the larger droplets growing at the expense of the smaller ones.
The rate with which this process takes place is defined by the oil’s aqueous solubility. The faster the oil is able to diffuse between the droplets through the water phase, the quicker the Ostwald ripening process will be. The natural solubility of cannabinoids in water averages around 0.0015 mg/ml, which is high enough to cause rapid nanoemulsion destabilization and too low for efficient absorption.
For a nanoemulsion of tricaprylin (C8 MCT oil) with an aqueous solubility level of 0.0004 mg/ml, the diameter of each droplet has been shown to double every 18 hours. Because of this higher solubility, this rate will be even higher for CBD/TCH that’s emulsified without a carrier oil.
This issue can be resolved by introducing 50% or more of a water-insoluble LCT carrier oil, such as olive oil, into the dispersed phase of the process. This reduces the rate of Ostwald ripening to a level that is nearly undetectable.
Long-chain free fatty acid source = greater bioavailability
Producing stable nanoemulsions through smaller droplet sizes isn’t the only function of carrier oils. They also help to maximize intestinal uptake. Studies have shown that the highest bioavailability following oral administration is achieved using an LCT carrier oil, such as olive oil, fish oil or corn oil.
To the contrary, the use of MCT oils (i.e. fractionated coconut oil) and non-tryglyceride oils (i.e. mineral oil) has been shown to drastically reduce bioavailability. This is ultimately due to the way poorly water-soluble compounds are transported through the small intestine.
Properly formulated nanoemulsions have been shown to maintain stability in the presence of saliva as well as gastric fluids. They can travel through the stomach to the small intestine relatively quickly, where they then combine with bile, phospholipids and lipases that are released by the gallbladder. If the nanoemulsion contains a digestible carrier oil, the lipases will convert it to free fatty acids which ultimately transport the cannabinoids into the bloodstream.
Carrier oils that are indigestible do not produce free fatty acids and, as such, cannot properly contribute to this process. Among digestible oils, LCTs perform better than MCTs due to the difference in lengths of the associated free fatty acid chains. Longer chains can solubilize more easily, which helps speed up their journey into the bloodstream, ultimately resulting in greater bioavailability.
How much carrier oil is necessary?
Generally speaking, the volume of carrier oil used in the formulation of nanoemulsion should exceed – at least to some degree – that of the cannabis extract or isolate. In most cases, 50-60% of LCT in the oil phase should be sufficient to minimize droplet size and prevent Ostwald ripening.
Where can I find CBD / TCH products that contain the right carrier oils?
As mentioned above, not all cannabinoid products are created equal. This is why it’s so important to partner with a provider and/or brand you can trust. At The CBD Store, all of the products we manufacture and sell are made using only the highest quality full spectrum carrier oils. This provides for maximum absorption and efficiency.
Have questions or concerns? Want to try a sample? Stop in and see us. Our knowledgeable staff will gladly assist you in selecting the perfect product for your needs.