UK medical cannabis: quality under scrutiny

Published: 11-Feb-2020

Andrew James, Marketing Director of Ellutia, explains how chromatography can uncover the potency of a batch of cannabis by detecting the different compounds it contains, using a readily available standard

Although campaigners for epilepsy and multiple sclerosis have welcomed the move to legalise this form of medicinal cannabis, this latest resurgence has fuelled the next wave of interest in the product, with its exaggerated marketing claims, links with high profile sports associations in a bid to establish new credentials and renewed discussion regarding its medicinal status.

With the total cannabis market estimated to be worth more than £16 billion during the next decade, the potential of cannabis is still emerging.1 What’s absolutely critical is to ensure the quality and integrity of the cannabidiol (CBD) source.

The challenge for cannabis processors lies in the lack of regulatory control regarding medicinal cannabis use. There is currently no global standard for the quality control of composition, adulterants, potency or the presence of any toxic residues, such as pesticides or solvents used in extraction.

Add to this the perceived difficulty of analysis, potential delays in the testing lab and the belief that an advanced skill set would be needed if testing were to be done in-house … and it’s clear why processors are skipping this vital step.

It can test for potency, terpenes, pesticides and residual solvents, all of which are essential to ensure quality, safety and consistency

Gas chromatography (GC), already a widely used tool for cannabis testing, may be the solution. GC is now being brought to mainstream use with new instruments that are accessible to users with minimal experience in a cost-effective, benchtop machine. It can test for potency, terpenes, pesticides and residual solvents, all of which are essential to ensure quality, safety and consistency in the UK cannabis industry, particularly as it moves towards full cannabis legislation.

A lack of standardisation

The lack of standardised regulations between states or countries for the quality control of cannabis has resulted in sporadic testing. For consumers in regions where it is legalised, this lack of standardisation means that it’s difficult to make an informed decision concerning the quality of the product they are purchasing.

No regulatory approval or clear product standards creates an almost tacit acceptance of all products, and consumers will tend to base their decision on price. This means that suppliers of cannabis derivatives can supply their products unhindered by regulation, which has implications on the credibility of the whole industry.

As the market for pharmaceutical cannabis products grows, so too does the scrutiny it comes under. A 2017 study published in the Journal of the American Medical Association found that nearly 70% of sampled products either exceeded or did not meet the labelled concentrations of CBD.2

As cannabis pharmaceuticals enter the market, clear regulations targeting the formulations and properties that are permitted are in development, which will have a significant impact on the future of the CBD industry.3

Andrew James, Marketing Director, Ellutia

Andrew James, Marketing Director, Ellutia

Towards in-house testing

Rather than relying on approved independent laboratories for product testing at the final stage before release onto the market, cannabis product manufacturers would be well advised to put tests in place much earlier in the product development process. These should ideally be done out in-house to identify potential issues earlier in the process and allow faster resolution.

Waiting weeks for results from various stages of the manufacturing process to be returned from external testing houses has serious implications on production cycles and time to market — and may mean that this vital step is missed out altogether.

New analytical instrumentation that no longer requires highly skilled operators is helping to bring product testing in-house. This access to robust and affordable analytical techniques will enable products to be tested rapidly and effectively, providing manufacturers — especially the smaller producers who have been instrumental in driving the development of the cannabis market — with an effective testing system and a viable and compliant route to market.

The benefits of gas chromatography

The core requirement when testing cannabis is the positive identification and quantification of the total tetrahydrocannabinol (THC):CBD ratio. For medicinal cannabis, CBD is the main component of interest — with high levels of CBD and low levels of the main psychoactive constituent THC being the preferred outcome.

The chemical composition of the cannabis determines the effects of each dose. This is further complicated by the many different strains of the cannabis plant, cultivated through cloning and selective breeding, all of which have different levels of each active compound, particularly the cannabinoid. As a natural plant rather than a chemically derived substance, it is difficult to control the natural compounds in any batch.

For this reason, bringing cannabis in line with other pharmaceutical testing would require batch testing for potency, flavour profiling and any residual solvents. Potency testing evaluates the level of each compound attributable to a potential health impact, including the cannabinoids delta-THC, cannabinol (CBN) and CBD.

Potency testing

Chromatography can uncover the potency of a batch of cannabis by detecting the different compounds it contains, using a readily available standard. A liquid sampling technique is preferable because the molecule sizes and volatility in natural cannabis are so varied that using a headspace methodology makes obtaining a fully representative sample difficult.

A compact gas chromatograph with a flame ionisation detector (FID) offers an efficient, time-saving, space-efficient and cost-effective combination that can be easily adopted.

Flavour profiling

Cannabis has many different varieties, which have a wide range of different effects. For medicinal cannabis to be regulated and therefore prescribed correctly for different purposes, determining its strain is essential. Flavour profiling is the way to establish strain identity through an analysis of the levels of compounds (such as terpenes) that are responsible for distinctive tastes and odours in the cannabis.

Residual solvent testing

The extraction of cannabis uses potentially harmful compounds, such as hydrocarbon gases and organic solvents, and testing for any residues is essential to ensure consumers are not put at risk. Substances could include residual levels of ethanol, for example, which has been linked with liver damage.

Residual solvents in cannabis can be tested through gas chromatography using a readily available standard. For effective testing, the components need to enter the gas phase, so headspace sampling is the most suitable method.

Future of cannabis testing

The current uncertainty around the prescription of cannabis-based products is being addressed. With the UK’s National Institute for Clinical Excellence (NICE) issuing new guidance for practitioners and with 33 US states legalising cannabis for medicinal purposes (and 14 legalising it for recreational purposes), this is an industry that is becoming increasingly regulated.4

Rather than rely on external verification throughout the manufacturing process, producers can take control of their own testing by bringing it in-house. Ellutia’s 200 series GC offers a reliable, space-saving, easy to operate and cost-effective solution.



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