In 2015 the American Chemical Society (ACS) started their cannabis subdivision aptly called the Cannabis Chemistry Subdivision (CANN). Since that time, the CANN has been one of the world’s most trusted sources for up-to-date cannabis research. Covering topics ranging from cannabinoid pharmacokinetics, testing and analytical methods, dosage, formulation, risk assessment and many others. The regular symposia given by the society are highly attended professional gatherings where cannabis scientists from around the world are given the opportunity to showcase the research that their labs have been conducting. Here we will review topics 5-8 covered in the Fall 2020 symposia.
Topics 5-8
Certified quality control analyst Shannon Swantek discussed the current role of analytical testing in the cannabis industry and the areas where improvements are needed in ISO standards to meet the needs of the industry. The rapid evolution of the cannabis industry has led to improved quality standards throughout the industry including in manufacturers as well as the labs that service them. Cannabis manufacturers are moving towards a realm of greater standardization and quality as the industry braces for wider cannabis regulations including cGMP manufacturing processes. The labs servicing these manufacturers are maintained according to ISO/IEC standards, however these standards have not been updated to accommodate the unique requirements of the cannabis industry.
ISO/IEC 17025:2017 standards are a set of international lab standards that laboratories around the world use to ensure proper lab procedures are carried out. These procedures are meant to be very broad so as to apply to a wide variety of industries and lab settings. They also include everything from handling client requests and samples to delivering results all the way through record keeping and handling client complaints. The testing that labs following these standards conduct becomes set based on the needs of the specific industry that the lab operates in.
The cannabis industry is unique compared to other industries however and the total scope of testing needs within the cannabis industry is not totally set, or consistent from one place to the next. As such, there is a need for cannabis stakeholders and operators to understand the areas in which the ISO/IEC standards may be limited in regards to the industry and utilize the channels laid out by the agencies to work towards repairing these gaps and limitations within the standards as they pertain to the cannabis industry. The most important requirement of ISO/IEC is that the labs meet the needs of their clients, oftentimes within the industry, the disconnect between labs and manufacturers prevents this need from being fully met.
Oftentimes the labs in the industries are unaware of the specific needs that clients have when products are being received and the operators are unaware which details are of importance to lab practices and results. Aspects such as carryover blanks, calibration ranges and sample preparation will all go a great way in determining the results of analysis so it is imperative that labs and operators develop reliable routes of communication in order to ensure the highest value out of the lab practices being implemented within the industry.
Dr. Ted Simon spoke about the fact that bias in data obtained from passive smokers has led to discrepancies in relation to passive cannabis exposure results in urine analysis. This is based on reviews of passive cannabis exposure studies along with computer extrapolation across the population. At the core of the issue here is the inherent flaws associated with original data that have been used as standards across the drug testing industry. Using extrapolation it can be determined that statistically relevant numbers of false positive tests as well as false negative test results have been the outcome for the application of these bias based studies.
A number of factors play into the concentration of the cannabinoid metabolites presence in urine analysis. The factors include the amount of time that has passed, the amount of urine collected in the sample, as well as individual factors such as cannabinoid metabolism and individual level of hydration. All of these factors can affect the overall level of cannabinoid concentration in a given urine sample. However, studies conducted, leading to current testing practices have not given adequate considerations to all of the factors affecting urine analysis results, leading to inaccuracies in testing. Key considerations that have been left out are the time between exposure and sample collection, water consumption, and the overall volume of the urine sample collection.
Testing analysis looks for cannabinoid metabolites that come from the breakdown of Δ9-tetrahydrocannabinol (THC) within the body. Cytochrome oxidase enzymes convert the THC to 11-nor-9-carboxyΔ9-tetrahydrocannabinol (THCCOOH), which can then be attached to a sugar molecule forming THCCOOH-glucuronide. The THCCOOH and THCCOOH-glucuronide are the compounds that are analyzed in urine analysis to determine cannabis use. Urine analysis then relies on the sum of the quantified data obtained from the urine sample received.
Previous studies done on passive exposure in 1977 and 1983 respectively, led to wide variances in passive exposure, with results of 260ng/ml and 20ng/ml respectively. When using statistical extrapolation from pharmacokinetics modeling programs however, and inputting data from the Centers for Disease Control, the modeling over large populations suggest that the initial bias in these early studies have led to significant error in terms of false positive drug screens. It has been believed that the uncertainties in the baseline levels for passive cannabis exposure may account for between 3% and 4% false positives, the new statistical modeling however suggests that number may be closer to 15% false positives.
These inaccuracies stem from variations in key sample collection factors that were not previously considered in research. Sample collection practices such as timed sample collections and sample pooling, are not representative of how workplace drug testing is conducted. Overall the error in sample collection methods during the initial studies led to reduced number of false positive test results among passive smokers. This error due to bias curtails the ability to use data obtained from these studies to use for determining baseline passive cannabis exposure limits in workplace drug testing.
In a discussion about the applications of adsorbents within the cannabis industry, Dr. Jerry King discussed ways in which chromatographic techniques may optimize the efficacy and lifespan of adsorbent materials. This becomes increasingly important as the cannabis industry becomes more sophisticated and incorporates adsorbent materials more into the laboratory and safety equipment utilized in the industry. Currently the uses for adsorbent materials includes: in safety materials, adsorbents are used to trap particles such as in safety masks or environmental filters; in lab practices, adsorbents can be utilized to remove contaminants or unwanted particles from oils, such as in removing THC from cannabidiol (CBD) oils; in analytical labs, adsorbents are used in equipment that allows for the quantification of various compounds in an oil solution.
In all of the areas where adsorbents are used, there is a general underlying principle to their application. Adsorbents bind to and hold a particular molecule of interest while letting others pass through. In some applications such as environmental filters, the desired compounds are trapped, ideally never being allowed to pass through, assuming proper maintenance and replacement. In other applications such as chromatographic techniques, the desired compounds are often held for a short time within the column, but are washed out of the column at a desired point. Considering the importance of adsorbents in the functions that they perform within the cannabis industry, proper studies regarding adsorbent efficiency and usable lifetimes must be conducted to ensure optimal operation within the industry.
Among the factors which affect the ability of the adsorbent to function optimally are, the adsorbent material, the desired sorbents (target molecules), temperature, volume pressure and more. If the adsorbent material is not optimized for the sorbent, then the separation of compounds will not be as clean as desired. Similarly, if the same adsorbent is overloaded or used for too long, the desired compounds can escape. The amount of the desired sorbent that runs past the adsorbent without being trapped is referred to as the breakthrough volume. When this breakthrough volume becomes higher, the adsorbent is working with a decreased efficiency.
While Dr. King’s research is focused primarily on optimizing adsorbents in relation to CO2 supercritical fluid extractions, the same factors motivating his research apply to all areas of the industry utilizing adsorbents. Optimizing the absorbent for both the best possible interactions with the desired sorbent, as well as optimizing the stability of the adsorbent for a particular application, increases the effectiveness as well as the life span of the adsorbent. This data can then be further used by manufacturers to predict usable life of materials and regular maintenance intervals allowing for consistent operations and predictable product performances.
Michael Coffin, along with Dr’s Condron and Fettinger, presented on the crystal structures formed from a variety of cannabinoids that are increasing in popularity in the cannabis markets. As the cannabis market grows and becomes more sophisticated, cannabinoids that were once considered rare are becoming widely available as isolated cannabinoid products. While there are many similarities between the various cannabinoids, the small differences in the atomic arrangement of the atoms can result in different crystallized structures being made. The scope of the work performed by the presenters was to provide information on the crystal structure arrangements of the cannabinoids, THCA, CBD, cannabinol (CBN) and cannabigerol (CBG).
In order for crystal structures to develop, the molecules have to line up in a very ordered manner, resulting in a crystal lattice structure that gives the crystals a consistent overall structure when they develop. Different types of molecules can crystallize into different lattice structures, of which there are a total of 7 different types of crystal lattice structures. Developing crystals is the most purified form of a compound as the ordering of the molecules pushes other contaminants out of the way in the formation of the crystal structure. These structures are then analyzed using X-ray diffraction to determine information about the molecule in the crystal structure, including the shape of the crystal structure itself.
As the crystal structures develop, they take on symmetry elements that allow researchers to determine further information about the bonds and connectivity of the atoms within the molecule. The molecules under investigation are all quite close in both chemical formula and molecular mass. CBN is the smallest of the four compounds in the study having 4 less hydrogens than CBD. CBG is slightly bigger than CBD having an additional 2 hydrogens. The largest of the molecules is the THCA which still contains a CO2 group that the other molecules do not have, making it significantly larger than CBN, CBD, or CBG which are all relatively close in size to each other. None of that however is new information, just important to researchers when considering the crystal structures.
Having successfully formed the crystal structures of all the desired compounds, the group was able to analyze the crystals through X-ray diffraction, bombarding the crystals with X-rays and observing the scatter patterns in the waves. The diffraction patterns of the waves are determined by the atoms, and bonds within the crystal structure allowing the researchers to fully determine what the molecules look like in three dimensional space. The crystal structures for the compounds in review were determined, and it was determined that CBN and CBD both develop monoclinic crystal structures, while THCA and CBG both develop orthorhombic crystal structures. This information allows researchers to develop empirical data on these molecules that further research can use to target additional studies on this array of important bioactive molecules.