Are We Underestimating the Pharmaceutical Potential of the Cannabis Plant?

James Duckenfield, CEO of Glass Pharms^®, explains why we may be underestimating the pharmaceutical potential of cannabis, and how research, formulation and more controlled delivery could help realise it.

Yes, I think it is safe to say that the UK is currently underestimating, or at least underutilising, the full pharmaceutical potential of cannabis.

This is not meant as any form of criticism of where the industry currently sits, and I do not see this as a failure of science. Cannabis tincutures could still be legally prescribed in the UK until 1973, yet it took another 45 years for cannabis-based medicines to return to legal prescribing. That interruption left a considerable gap in clinical education, while regulation has continued to struggle to keep pace with the law it is meant to implement.

The first specific cannabinoid receptor binding site was characterised in 1988, before the CB1 receptor was cloned in 1990. The wider endocannabinoid system came into view over the following decade, with the discovery of anandamide, CB2, and 2-AG. By the 2000s, major pharmaceutical companies were actively developing drugs targeting cannabinoid signalling. 

But nearly forty years on, only one UK university includes the endocannabinoid system in its medical syllabus.

That said, UK patients and prescribers now have access to a broad range of cannabis based products for medicinal use. The range of cultivars, oils, edibles, capsules, and vape cartridge options now on offer would have been close to impossible to imagine back in November 2018, when medical cannabis became a legal reality here in the UK. 

But that variety reflects what we have so far learned to produce, characterise and prescribe consistently. That is simply not the same as the plant having reached its pharmaceutical endpoint.

That’s where we step in, with Glass Pharms^® leading the UK medical cannabis cultivation industry and backing that position with significant investment in research and development, working on the cultivars, formulations and delivery methods that come next. 

Does today’s market show us the plant’s full potential?

Almost all medical cannabis options prescribed in the UK today rest on two molecules. THC and CBD are the two ‘major’ cannabinoids produced by cannabis plants, and are comparatively well characterised. 

But cannabis flower is not a two-molecule medicine. It is a complex botanical material containing more than 100 cannabinoids, alongside terpenes and flavonoids. Many of these compounds have been known to science for decades, yet their individual and combined pharmaceutical potential remains far less developed. 

Cannabigerol (CBG) and tetrahydrocannabivarin (THCV) are two of the more intriguing potentially therapeutic cannabinoids, and both are the subject of real research interest. With that emerging research comes a supply problem, and it is one we have been working on at Glass Pharms. Our CBG-rich cultivar has been available to eligible patients for more than two years, and we have a THCV-rich medical cannabis flower on the verge of release. 

Neither compound is particularly exotic, and both have been known to science for decades. The reason they haven’t been widely prescribed since medical cannabis became legal in 2018 is simply that producing a plant which expresses a minor cannabinoid reliably, batch after batch, takes time and effort. 

And a lot of expertise. 

That is the work we have been doing in Wiltshire, and it is why I do not think today’s available formulary fully describes the plant potential. It is dictated by what the supply chain has so far been able to deliver, and what the emerging research can so far prove.

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How can pharmaceutical potential become clinical confidence? 

I believe that both patient and prescriber confidence grows in line with two main factors: education and control. 

Clinicians need to understand and trust that the treatment option they are prescribing actually delivers the correct dose, so that treatment can be titrated and reviewed as it would be with any other medicine. Patients need the same assurance, and overwhelmingly look to their prescribing specialist for it. Someone managing a long-term condition needs to know that what worked last month will work the same way this month, and that a change in how they feel reflects their condition rather than their medicine.

That is where flower is an outlier. Clinicians are used to prescribing in milligrams or micrograms, through delivery mechanisms with well-understood pharmacology behind them. Cannabis flower does not yet work that way, and it is worth setting out exactly why.

The current permitted tolerance on flower in the UK is within 10% of the label claim. 

• A cultivar labelled at 25% THC may legitimately test anywhere between 22.5% and 27.5%.
• The patient then has to weigh out each dose themselves. A 0.2g prescription, weighed to that same 10% tolerance, means anything between 0.18g and 0.22g.
• Those two variables stack. A patient expecting 50mg of THC could take 60.5mg at the top of both ranges, or 40.5mg at the bottom.

That is a swing of roughly 20% either side of the intended dose, before anything else about the patient, the device, or the technique is taken into account.

Some of that is simply the nature of the material. Flower is a natural product, and no two plants are ever truly identical. A great deal of our work, and a large chunk of our investments, exist to narrow that variation. 

• We work from carefully selected tissue-culture clones rather than seed, which removes the genetic drift inherent to seed-grown crops and means every plant in a batch starts out genetically identical.
• Our early discovery work with reputable seed sources delivered up to six distinctive phenotypes from a single, supposedly homogeneous, packet of seeds.
• More than ten growing factors are then controlled using AI and remote sensors, with a robotic platform moving batches through the facility so that each growth stage gets exactly the conditions it needs

That gets you a long way. It does not get you to a tablet. 

Oils can improve dosing control considerably. An oral syringe provides a familiar, easy-to-use way to measure a defined volume accurately. Even then, consistent dosing still depends partly on how the medicine is administered. 

Cannabinoids absorbed through the blood vessels in the mouth have significantly better bioavailability than those that are swallowed, so an oil held under the tongue and an oil swallowed too early do not equal the same dose. 

One can envisage other forms that would deliver more control still.

What could the next phase of cannabinoid medicine in the UK look like?

Encouraging work is already under way. Storz & Bickel’s dosing capsules, and the Class IIa medical device certification behind their vaporisers, are important steps in the right direction for flower dosing precision. 

Our own work is aimed squarely at the same problem. We are developing pharmaceutical forms of cannabis-based medicines, both inhaled and oral, designed around dosage control and ease of use.

That matters more than it might appear. Germany and France have both shown that regulators remain uncomfortable with loose flower as a pharmaceutical product. Patients, meanwhile, continue to choose flower because it works for them. Those two positions need to be brought together, and better delivery is how it happens. Not by taking away a format patients rely on, but by giving regulators the control they are asking for.

The rest follows from there. We already have licensed medicines that use cannabinoids safely. On that basis it is not unreasonable to see cannabis medicine as being near the beginning of an important journey rather than the end of one.

So, to return to the question. Today’s market is not the limit of what this plant can do. It is the foundation we build from, and it is educators and regulators who are now best placed to set the rest of it free.