The ABC of CBD
Written by Anjali Singh
As per the U.S. National Institute of Health, the human endocannabinoid system (ECS) is actively involved in the homeostasis and physiological processes via cannabinoid receptors present throughout the body. Cannabis sativa extract affects the ECS primarily by the presence of cannabidiol (CBD), which is believed to ameliorate symptoms of pain, and tetrahydrocannabinol (THC), which imparts the extract a potential of substance abuse and psychological addiction. Cannabis containing more than 0.3% THC is termed as Marijuana. For a long time, cannabis was mainly overseen by the stringent federal Controlled Drug Substances Act of 1970, prohibiting its agricultural cultivation and medical use. However, owing to the extensive illegal hemp farming, rampant use of non-prescription cannabis based medicines and the ever-increasing scientific evidence of its therapeutic properties, the United States Farm Bill descheduled a wide-range of cannabis products in 2018. This move is estimated to catapult the US cannabis market from $2.3 billion to $20 billion by 2020. According to Arcview Market Research and BDS Analytics, the global cannabis market is estimated to grow to a staggering $57 billion by the year 2027, of which 33% will be contributed by medical marijuana1.
A direct consequence of the US Farm Bill is visible across the biopharmaceutical sector, which has started to incorporate CBD as an active ingredient into their formulations for treatment of painful and inflammatory conditions. On Nov 1, 2018, Epidiolex® became the first FDA-approved drug containing purified CBD, available as an oral solution and marketed by Greenwich Biosciences Inc (US subsidiary of GW Pharmaceuticals Ltd.)2. This has led the industries to look for a controlled supply of purified cannabis-based active ingredients and appropriate biophysical characterization methods to avoid misbranding and putting the consumer health to great risk. TresViva®, a subsidiary of Arendis from Montrose, Colorado is one such company which is taking a major step in providing certified and standardized THC free and full spectrum CBD to end users. They are dedicated to cultivating highest quality of hemp and plan to establish a core facility at par with international standards to precisely quantify cannabinoids for downstream applications. Andrew Lucero, from TresViva®, is currently working on multiple projects using standardized CBD to prepare tincture nano-emulsions for sublingual use. From a pharmaceutical standpoint, CBD is a highly water insoluble compound yielding poor oral and topical absorption and biodistribution patterns, in vivo. The team at TresViva® is using sonication and micro-fluidization techniques to skillfully form nano-emulsions for enhancing CBD oral absorption and bioavailability. The nanoparticle-based drug delivery approach combined with a consistent and sensitive platform to measure true particle size parameters can lead to a well-characterized and stable nano-formulation for clinical use.
Andrew Lucero from TresViva
In an interesting study on oil-in-water (o/w) nano-emulsions, researchers at Victoria University of Wellington, New Zealand successfully demonstrated the utility of Tunable Resistive Pulse Sensing (TRPS) technology to identify changes in droplet size, size distribution and zeta potential in a simulated milk model (an o/w emulsion of non-conductive soybean oil droplets in phosphate buffer) stabilized by beta-lactoglobulin (BLG)3. Ability to accurately measure size, size distribution and particle concentration over a period of 4-months allowed the researchers to gain insights into formulation stability and particle aggregation patterns. In addition, salt-induced droplet aggregation, achieved by increasing the molarity of phosphate buffer to 1M, showed that the pattern of droplet size increase followed a distinctive scheme for both data sets shown by the distribution plot by particle number. It was concluded that TRPS was able to impart good sensitivity for examining time-dependent particle growth and zeta potential variations in nano-emulsions, both of which are critical factors for quality control. The same analysis was also executed using dynamic light scattering (DLS) and produced less precise results.
More and more scientific groups are looking for a controlled source of cannabis for investigating ways to augment CBD solubility using nanotechnological platforms. Dedicated single particle analysis holds the key to accurately characterizing such multi-modal nanobiological systems. Coming of age high-resolution particle characterization tools will not only facilitate a comprehensive measurement of critical physico-chemical parameters but also expedite their clinical and regulatory acceptance.
- Somerville, A., Willmott, G., Elridge, J., Griffiths, M., & McGrath K (2013). Size and charge characterisation of a submicrometre oil-in-water emulsion using resistive pulse sensing with tunable pores. Journal of Colloid and Interface Science, 394, 243-51. doi: 10.1016/j.jcis.2012.11.071