By Emily Ledger
The transdermal patch has become a familiar item with most people in the 21st century – from its first approved version in 1979 with the scopolamine-infused patch for motion sickness to the most well-known, the ‘nicotine patch’, famed for helping countless smokers curb the habit.
But a fairly new ingredient has been taking the transdermal industry by storm (along with every other industry) – CBD. Starring in products from coffee and alcoholic drinks to hand cream and chocolate, cannabidiol’s popularity is set to continue throughout 2020, and beyond. But how does a CBD patch actually work?
First of all, as always, a CBD patch will not get you high. In order to be called a CBD patch, THC (the Cannabis component that does get you high) has to be minimised. What’s more, to be legal in the UK, all CBD products must contain almost no THC in the first place.
How Does a CBD Patch Work?
A CBD patch (and all other transdermal patches, for that matter) work by taking advantage of a drug concentration gradient. This means the ingredient contained inside the patch in a large concentration, will naturally want to spread to an area with a low concentration of that ingredient.
For example, think of adding hot water to a cool bath. At first, one part of the bath will feel warmer, but eventually, the temperature will level out. This is because the heat will naturally want to spread out to the surrounding area.
This gradient, from high concentration to low concentration, effectively pulls the CBD (or scopolamine, or nicotine) from the patch, into your skin. The patches are best placed in an area of skin with a high concentration of veins so that the ingredient can be absorbed into your bloodstream.
Matrix Vs Reservoir Patches
Since the invention of the transdermal patch over 40 years ago, two models have been used commercially: The Matrix patch and the Reservoir patch. Both patches feature an adhesive layer, which allows it to be stuck to your skin.
The main difference between the two models is the way in which they release the ingredient. In Matrix patches, the rate of release is not accurately controlled. The dosage received will simply depend on the amount of CBD contained inside the matrix, and the size of the patch.
On the other hand, the Reservoir patch features a drug reservoir within the patch. This is often a gel that holds the ingredient. As opposed to the Matrix model, this kind of patch utilises a ‘Release membrane’. This added feature allows a controlled amount of CBD to be released from the patch. The Reservoir patch has become the more successful, and widely used of the two transdermal patch models.
What are the Benefits of CBD Patches?
Transdermal patches can lend a whole host of benefits to the average user of CBD products. For example:
A CBD Patch is more discrete
Many CBD products might be characterised by a somewhat awkward delivery method. A tincture, for example, though one of the most effective ways to take the cannabinoid, means dripping an oil under your tongue. This can be difficult when you are in public.
They bypass the liver and stomach
When you ingest a CBD product, such as an edible or a tablet, the CBD then has to pass through your stomach and liver. Both of these organs are designed to break down anything that goes into them. This essentially dilutes the CBD, meaning that less of the start product is absorbed effectively. This is known as the First Pass Effect.
Through a transdermal CBD patch application, this is bypassed, allowing the CBD to be absorbed directly into your bloodstream.
They deliver a more accurate dose
As opposed to other methods, such as oils and vapes, transdermal application releases CBD slowly over a number of hours. They can also be formulated for specific results. This can include specific cannabinoids – such as pure CBD – for improved medicinal value.