What is a Stability Study & Why is it Important for Cannabis Products?
A stability study examines a pharmaceutical product’s “therapeutic potential” when placed in varying environments (Kosovic et al., 2021). In relation to cannabis, stability studies evaluate how cannabis products stand the test of time. They are vital to know the best ways to package, store, transport, and display cannabis to maintain its potency and quality from harvest to shelf. They also provide an accurate way to determine “best-by,” “sell-by,” and “expiration” dates, so consumers can know how long their cannabis should last.
Discussing the Shelf-Life Data of: Dried Flowers
Dried flowers are perhaps the oldest method of consumption, with phytochemical analysis of the Jirzankal Cemetery in East Asia showing evidence of ritualistic cannabis smoke from 500 BCE (Ren et al., 2019). That said, dried flowers have shelf-life precautions that must be accounted for.
It’s common knowledge that as soon as the cannabis plant is harvested, degradation begins (Bennett, 2020). Ideally, the best way to store dried flowers is at moderate temperatures with humidity between the 59-63% range and ensuring that the flower is given limited light exposure (Bennett, 2020).
Temperature can cause a loss in cannabis quality; if the temperature exceeds 70 degrees Fahrenheit, the flower becomes a hotspot for bacterial and mold growth (Bennett, 2020). On the other hand, if the cannabis is kept too cold (like in a freezer), that could force moisture into the plant and break down its trichomes (Bennett, 2020).
In a study focusing on how temperature affects cannabis potency, Juris Meija et al. had some interesting findings. When stored at room temperature, the “THC content of cannabis decreases at a rate of 3-5% per month” (Maija et al., 2021). For the first 100 days, when stored at 22 degrees Celsius, the average THC content declines by 12% (Maija et al., 2021). This study found that storage at room temperature is not suitable for cannabis, and even “storage at +4 degrees Celsius fails to maintain a reasonable long-term stability” (Maija et al., 2021).
Discussing the Shelf Life Data of: Concentrates & Oils
Cannabis oils and concentrates are becoming increasingly popular ways to consume cannabis’ desirable ingredients. With this rise in marketability comes the need for research on the best ways to preserve and maintain these products quality.
In a study focusing on how cannabinoid-infused oil and cannabis-infused tea reacted in different temperatures, Roberta Pacifici et al. found that 80-85% of the oil’s initial potencies were at ordinary and refrigerated temperatures after 14 days (Pacifici et al., 2017). Their findings read that with the oil, “heat not only decarboxylated acidic compounds but also significantly increased the final concentrations of cannabinoids” (Pacifici et al., 2017).
On the other hand, the tea had the highest concentration of cannabinoids after 15 minutes of boiling but then had a 50% or more decrease in THC and CBD content after 3 and 7 days, respectively (Pacifici et al., 2017). This was found to be the same when the tea-infused cannabinoids were refrigerated at 4 degrees Celsius (Pacifici et al., 2017).
Another study by the University College London focused on cannabis tinctures (alcohol-based cannabis concentrates) and how they last over time. The study found that after three months, the ‘shelf life’ of cannabis showed such a progressed amount of decarboxylation and overall reduction of neutral cannabinoids that they discontinued that part of the test (Peschel, 2016). It also showed that the ‘fridge’ tinctures lasted longer; after 15 months, the product showcased a drastic spike in THC and CBN content, so much so that even after the product began presenting other degradation processes, the THC levels were still higher than freshly made tinctures (Peschel, 2016).
Discussing the Shelf Life Data of: Edibles
Edibles require different stability testing strategies because they’re mixed with food ingredients, which have their own regulated limitations. The U.S. Department of Justice’s Drug Enforcement Administration released a report in 2017 detailing an overview of marijuana edibles. They report that while the “analyses of alkaloids in foodstuffs is a very heavily researched topic,” the stability and durability of marijuana edibles is not (Klein, 2017). Robert Klein discusses how the wide variety of ingredients in prepared edibles, the differing THC sources being used, and the sampling challenges from “the inherent heterogeneity of most solid food products” are part of what makes it so difficult to analyze marijuana edibles accurately (2017).
However, in a study focusing on the stability of THC and CBD in baked brownies, Carl Wolfe et al. found that out of the ten brownie mixes they tested, none interfered with the THC and CBD contents (2017). Likewise, when stored at room temperature, the baked brownies were stable for up to 3 months (Wolfe, 2017).
Stability Studies are Important to Ensure Quality Products
We know that the goal is to produce excellent products, and we also know that those excellent products must maintain their quality from the moment they are packaged until they arrive in the hands of the consumer. As more states legalize the use of medicinal and recreational marijuana, the need for accurate and reliable cannabis testing will grow, too. That is why at Steep Hill, we have locations throughout the country dedicated to supporting your cannabis testing needs. To learn more about our testing services, visit steephill.com.
Bennett, P. (2020, July 28). What influences degradation of THC and other cannabinoids? Leafly. Retrieved October 13, 2022, from https://www.leafly.com/news/cannabis-101/factors-influencing-cannabis-degradation
Klein, R. F. X. (2017). Analysis of “marijuana edibles” – food products ... - dea.gov. Retrieved October 13, 2022, from https://admin.dea.gov/sites/default/files/pr/microgram-journals/2017/mj14-1_9-32.pdf
Kosović, E., Sýkora, D., & Kuchař, M. (2021, March 19). Stability Study of Cannabidiol in the form of solid powder and sunflower oil solution. Pharmaceutics. Retrieved October 12, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8003596/
Meija, J., McRae, G., Miles, C. O., & Melanson, J. E. (2021). Thermal stability of cannabinoids in dried cannabis: A kinetic study. Analytical and Bioanalytical Chemistry, 414(1), 377–384. https://doi.org/10.1007/s00216-020-03098-2
Pacifici, R., Marchei, E., Salvatore, F., Guandalini, L., Busardò, F., & Pichini, S. (2017, August 28). Evaluation of cannabinoids concentration and stability in standardized preparations of cannabis tea and cannabis oil by ultra-high performance liquid chromatography tandem mass spectrometry. Clinical chemistry and laboratory medicine. Retrieved October 12, 2022, from https://pubmed.ncbi.nlm.nih.gov/28207408/
Peschel, W. (2016, April 18). Quality control of traditional cannabis tinctures: Pattern, markers, and stability. MDPI. Retrieved October 12, 2022, from https://www.mdpi.com/2218-0532/84/3/567/htm
Ren, M., Tang, Z., Wu, X., Spengler, R., Jiang, H., & Boivin, N. (2019, June 12). The origins of cannabis smoking: Chemical residue evidence from the first millennium BCE in the Pamirs. Science Advances. Retrieved October 12, 2022, from https://www.science.org/doi/10.1126/sciadv.aaw1391
Wolf, C. E., Poklis, J. L., & Poklis, A. (2017, March 1). Stability of tetrahydrocannabinol and cannabidiol in prepared quality control Medible Brownies. Journal of analytical toxicology. Retrieved October 13, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5412015/