Oral Ingestion of Hemp Oil
Topical Absorption of Hemp Oil
Absorption through an intact skin is an extremely complicated process and there are many conflicting clinical studies that exist. The main reason for varying results is that a drug transport through the skin depends on many factors and different compounds absorb via different routes. Transport of drugs though the skin happens either through the inter-cellular spaces/channels, or through hair follicle channels and sweat glands. The flux depends on parameters like the water activity of the drug delivery system as well as the skin, the composition of the drug delivery matrix and the drug compounds themselves and many other factors. Human skin is a layer that protects us from the environment outside the body, so naturally penetrating the top layer is extremely difficult.Depending on the molecular weight and hydrophilicity/lipophilicity of the substance that comes in contact with the skin, the transport through it changes. According to the “500 Dalton” rule, if a substance has a molecular weight of more than 500 Dalton, it will not be able to penetrate the top layers of skin through the intercellular channels. If the substance is an oil and it has a molecular weight of less than 500 Dalton, it will penetrate through the intercellular channels because those channels are made of phospholipid bi-layer and so are lipophilic.
GI Tract Bio-availability Improvement
In order to increase the bio-availability and absorption, the oil droplet size has to be decreased. In order to do that, some use devices like microfluidizers and others use ultra-sonification, however the one common thing is that an appropriate emulsifier system is needed in order to be successful. Most people use synthetic emulsifiers like Tween 80, Span 80, and solvents like Propylene Glycol and Ethanol to achieve a 100nm-200nm droplet size, which results in a milky nano-emulsion. Some small number of companies even achieve 50nm-100nm droplet size range. However, clinical studies performed on various Cyclosporine nano-emulsions (https://sci-hub.se/10.1002/jps.20057) found that the nano-droplet size correlates with the GI Tract bio-availability (blood concentration) in a following manner: In case of the oil droplet size range of 100nm-1000nm the bio-availability improves marginally and is similar to the bio-availability of the micro-emulsion. This is why, emulsions with droplet size of more than 100nm are considered micro-emulsions and not nano-emulsions. When the droplet size dips below 100nm there is a spike in bio-availability and the emulsion is considered a nano-emulsion. Most emulsifiers and technologies can only achieve a slightly sub 100nm droplet size, but some do reach 60nm-100nm sizes. In that range the bio-availability does not vary significantly and the nano-emulsion is still milky white, but as soon as the size drops to 60nm, the nano-emulsion is translucent and the bio-availability spikes again and changes significantly with the slightest change in the droplet size. See (Pic. 3) for the nano-emulsion translucency v.s. droplet size, and (Pic.4) for blood concentration v.s. droplet size.