With the growing number of states implementing programs permitting access to medical and recreational cannabis products, the need for accurately testing and maintaining quality control, dosing, and proper labeling of these products will also increase in importance as the industry progresses. At the 251st American Chemical Society (ACS) National Meeting and Expo in San Diego, Members of the ACS Cannabis Chemistry Sub-division came together to discuss some of the challenges in cannabis regulation. Two such members; Dr. Jahan Marcu, Chief Scientist for Americans for Safe Access, and Analytical Chemist, Melissa Wilcox, addressed the topic of cannabinoid testing in edibles.
“Many edible producers have noted inconsistent test results from different laboratory testing facilities. It is not uncommon to send samples to multiple labs and have different results come back from each of them.” -Melissa Wilcox
Cannabis itself is a chemically complex substance and when infused into products such as cookies, brownies, and candies it gets mixed into an even more complex matrix. Ingredients like fats, sugars, gelatins, food colorings, and other compounds make extracting the cannabinoids a more difficult task and also make it difficult to analyze using HPLC (High Performance Liquid Chromatography) which is the typical method for analyzing cannabinoid potency. These compounds can get in the way or even mask the components in the analysis and also potentially reek havoc on expensive HPLC components; requiring the need for maintenance on a more routine basis. In some cases, laboratories have stopped taking edible samples simply because it was too damaging to the equipment.
“It was clear that a better method of analyzing cannabis-infused edible and topical products was needed. Our approach in developing a new method was to improve the sample preparation step to make sure all of the cannabinoids were extracted from the matrix components, which greatly increases the accuracy of the results, as well as spare the testing equipment from fouling.” -Melissa Wilcox.
To ensure a complete extraction, the sample is first prepped using a cryomill which grinds the material into an extremely fine powder through a combination of milling and deep freezing with either liquid nitrogen or dry ice, it is then mixed with a fluffy silica material called celite to keep the mixture a free flowing powder. The second step involves using flash chromatography to isolate the cannabinoids from the matrix components (fat, sugar, etc). From there the cannabinoid sample can be easily run on an HPLC to quantify the cannabinoids in the sample. Although more testing will need to be conducted, this technique has already been successfully used to on many different products such as cookies, brownies, chocolate, lotions, and even gummy and sticky confections which are commonly stated as being some of the most difficult to analyze.
The methodology for analyzing cannabinoid content in edibles is extremely important for the future development of the industry; not only for the testing labs and producers who are seeking a truly consistent product, but ultimately it’s important for the users and patients to know what level of cannabinoids are in the products they are consuming. In a 2014 study conducted by the Journal of the American Medical Association (JAMA), a variety of different edible products were obtained from cannabis dispensaries in three different cities- Seattle, San Francisco, and Los Angeles. The report states: “Of 75 products purchased (47 different brands), 17% were accurately labeled, 23% were under-labeled, and 60% were over-labeled with respect to THC content. The greatest likelihood of obtaining under-labeled products was in Los Angeles and over-labeled products in Seattle.”
Additionally: “Non-THC content was generally low. Forty-four products (59%) had detectable levels of CBD; only 13 had CBD content labeled. Four products were underlabeled and 9 were overlabeled for CBD. The median THC:CBD ratio of products with detectable CBD was 36:1, 7 had ratios of less than 10:1, and only 1 had a 1:1 ratio.”
For those who are in need of specific cannabinoid profiles and ratios to suit there needs, it is indeed vital to ensure that patents and consumers are given better methods for which they can rely upon to insure their health, wellness, and enjoyment. We’d like to thank Melissa Wilcox and Jahan Marcu for taking the time to speak about this important part of a developing industry.