Testing THC Edibles: Stability Testing in the Cannabis Segment

Since 2012, the legalization of cannabis-infused edibles has been passed by several states in the U.S. Since October 2019, cannabis-infused edibles have also been for sale in Canada, although they are mostly banned from Quebec. This may be news to some as the legalization and sale of cannabis leaves and extracts are handled differently than that of a formulated edible. Whether for recreational or medicinal-use edibles impose new kinds of problems as the processed consumables possess different bioavailability and uptake routes in the body, leading to longer onset times and overdose potential when compared to standard inhalation methods. Label claims need to be met and verified in terms of potency testing and overall safety to the consuming public. Up to this point, testing has not generally been universally regulated due to the absence of a universal governing body to implement standards of what needs to be tested and what levels of accuracy are valid, leading to a wide range of quality within products. Many say that global legalization will allow for the expanded research of these drugs and their safety to the public, something that has been difficult to do.

How Can This Testing Be Done in a Short Period and With Quantitative, Accurate Results?

The Turbiscan range has been developed for nearly 30 years with a light-scattering technology that can monitor emulsion stability and detect the smallest change well before anything can be observed by the naked eye. Based on Static Multiple Light Scattering (SMLS), the Turbiscan device detects particle migration and size data to provide detailed comparisons of the creaming, clarification, sedimentation, and flocculation kinetics. Easy and rapid analysis of the THC creaming rate in an emulsion can be extrapolated into shelf-life or can simply be used as a pass/fail test. Not only does this present itself as a solution to shelf-life and potency testing but will also allow the formulating chemist to optimize the formulations quickly and rapidly.

This method has already been tested by Tarukino LLC in Seattle, Washington. Since it is known that HPLC testing of materials can change from lab to lab even for the same samples it was determined that utilizing the Turbiscan for long-term potency testing would be a good fit. Sampling with the Turbiscan is simple and requires only placing the material inside a 30 mL vial and sealing the cap. The same vial of an unaltered sample can sit upright for the entire duration of the test without the need for probing or stressing the sample in any way throughout the process. As the creaming of the sample is seen, the absolute volume fraction of oil can be calculated over time. Given the particle size (measured independently throughout the study) and the refractive index of the sample, the volume fraction can be calculated.

Users of the Turbiscan at Tarukino (Seattle, WA) see the creaming of a THC-infused emulsion over 200 days change no more than an absolute 1.75% change in the sample. With this critical information, they can be confident that their material can sit on a shelf for over 200 days without the need to worry about the quality of the product. Most importantly, the potency during this time will not be impacted in a significant manner and can likely be rendered homogeneous with simple redispersion (i.e., shaking).

Proper testing and validation of cannabis-infused products will likely require multiple methods to generate clean, viable, and stable products. While some testing methods may not be considered mandatory a collection of methods will result in consistently high-quality products that will ultimately help a brand develop and stand out from others in this competitive marketplace.