Question: I have been contemplating starting a business manufacturing cannabinoid- and terpene-infused topicals such as creams, salves, and bath bombs. But after reading your Tomorrow in Cannabis column titled “Solubility, Bioavailability, and the Future of Cannabis Consumption and Pharmaceuticals,” I'm realizing that simply micro- or nano-emulsifying a distillate and including it as an ingredient is not going to produce a quality product. Can you elaborate on why the active ingredients in that form are inferior?
Answer: A distillate or any form of cannabinoid that has been nano- or micro-emulsified is not capable of penetrating or absorbing into the skin and can't disrupt the skin's lipid barrier. Cannabinoids are fat-soluble molecules, making them effective in penetrating the lipid-rich outer layer of the skin. Still, their low water solubility and their ability to bind to the outer layer dramatically hinder their ability to permeate deeper into the skin and achieve systemic circulation.
For transdermal delivery, you must dramatically increase the cannabinoid’s solubility so that it interacts with the skin’s outermost layer and disrupts its lipid structure. Doing so requires utilizing compounds that increase solubility and stability, allowing cannabinoids to be released from the formulation and be absorbed into the skin barrier.
Examples of these compounds include terpenes like menthol and limonene, fatty acids like oleic acid, glycols like propylene glycol, phospholipids, and nanoparticle carriers like liposomes. The most effective formulations combine several of these approaches to maximize absorption.
The compound should also interact with skin lipids to enhance permeation into the lipophilic skin barrier, leading to increased penetration into the epidermis and dermis.
Regarding bath bombs, in my humble opinion, many bath bombs offer relief via placebo effect and aromatherapy, rather than the effects of cannabinoids or terpenes from cannabis.
The majority of bath bombs are made of a multitude of ingredients such as beeswax, sunflower lecithin, and essential oils. Emulsifiers and surfactants, such as polysorbate 80, are also key ingredients because cannabinoids are hydrophilic, meaning they do not absorb into water. Without these ingredients, the cannabinoids simply float on top of the water or stick to the sides of the tub.
Many (if not most) topicals and bath bombs do not have bioavailable cannabinoids (i.e., the cannabinoids do not enter the bloodstream). Despite this, numerous claims tout the health benefits of cannabinoid-infused bath bombs, including:
- skin health;
- arthritis;
- enhanced sleep;
- muscle spasms;
- carpal tunnel;
- muscle stiffness;
- menstrual cramps;
- back pain; and
- inflammation.
All of which combined leads me to ask: How is it possible for CBD to interact with the endocannabinoid system if it is not bioavailable and barely penetrates the stratum corneum, let alone enters the bloodstream?
The point is: If you are inclined to pursue your desire to manufacture cannabinoid- and terpene-infused topicals and bath bombs, you should strive to address the bioavailability and solubility of your products. Both are very important to providing your customers with a superior product that actually delivers the relief they desire.
Kenneth Morrow is an award-winning grower and breeder. He is the owner of Trichome Technologies, a research and development company. He is also a consultant and author of the book "Marijuana Horticulture Fundamentals" and a founding advisory board member of Cannabis Business Times, where he has been a columnist since 2015. Find him on Instagram @trichometechnologies or reach him via email at: [email protected].
