Purification by Crystallization

Crystallization is a standard laboratory technique for purification of compounds from a mixture. For hemp extracts, CBD readily crystallizes while THC and other impurities do not, this makes crystallization an excellent technique for purifying and isolating CBD. The process is accomplished by dissolving the hemp oil in a suitable solvent and then adjusting the solubility of the solvent through various mechanisms to cause the CBD to crystalize. We use a hydrocarbon solvent with a very low boiling point to make removal of the solvent after crystallization easier and more thorough. 

Crystal Size

One one of the biggest advantages of Mile High Labs' isolated CBD is the carefully controlled size of our crystals. Many other producers look to grow large, novelty sized crystals but there are many disadvantages to this. First, large crystals will trap solvent inside of the crystal structure which cannot be removed and is typically in the 100-1000 ppm range. Mile High Labs' isolate is tested at 0 ppm residual solvents. A second and very important advantage of smaller crystal size is better bioavailability. For edible and topical products, the amount of CBD that is absorbed into the body is proportional to the surface area of the isolated crystals. We control every parameter in the crystallization process in order to produce crystals in the size range of 50-150 micron. This gives us a very large surface area per gram of CBD. Many other manufacturers are producing CBD crystals in the 1000-2000 micron size range which will have much lower surface area per gram. 

The relationship between the crystal size and bioavailability is shown in chart above. The Mile High Labs advantage is evident from the plot, our 100 micron crystals have 15 times better bioavailability than the industry typical 1500 micron.

Yield and Purity

Many manufacturers have to make a trade off between process yield and purity. At Mile High Labs, we use careful control of the crystallization process in order to produce the best purity without compromising on yield; we obtain 99+% purity and 95% yield. This is done by using state of the art techniques and equipment. We utilize a custom built pharmaceutical crystallizer apparatus that allows us to carefully control the entire process.