There is a plethora of misconception about CBD and water solubility. Practically every hemp processing lab touts a “water soluble” version of CBD. To get to the root of the issue one must ask the question: Is it a dispersion, colloid or solution?
Is the CBD actually made soluble? Is the description of the actual product(s) (and underlining processes) truthful?
Before we present our conclusions, it is important to get clarity on key scientific terms and principles.
Dispersion: A process in which particles are dispersed in a continuous phase of a different composition. Dispersion is mostly related to solute particles. The dispersion of solute particles in solvents (e.g. water) leads to the formation of colloids or suspensions.
Solubilization: A process by which the solubility of a compound or rate of dissolution is increased. Solutions may be obtained as a result of solubilization of solute molecules or ions in the specified solvent.
Colloids: A mixture with particle sizes between 5 nm and 200 nm in at least one direction. The particles are large enough to scatter light and the colloid is typically opaque. Colloids are typically stable although the particles may agglomerate over time. A colloid has two phases, a dispersed phase (particles) and a solvent or liquid phase. A colloids can typically be separated by ultracentrifugation or filtration.
Suspension: A suspension is similar to a colloid where the particle size ranges from about 200 nm to 1,000 nm. The particles can often be separated out by normal filtration or centrifugation. The particles are more susceptible to coagulation or settling than with a colloid.
Solution: In a solution the solute and solvents consist of only one phase. A solution is homogenous and will not separate over any period of time. A solution cannot be separated by standard filtration or centrifugation. A solution transmits light and looks transparent. The solute size is molecular or ionic and less than 1 nm in all dimensions.
Solubility of a solute: LogS is way of calculating a compounds water solubility vs solution pH, expressed as the log10 of that solubility in moles/liter. The calculation can easily be converted to mg/ml. Using this calculator, the intrinsic solubility of CBD is 0.0004 mg/ml. at a pH rage from 4 to 10.
Micelle – A Micelle is a particle of colloidal dimensions that exists in equilibrium with the molecules or ions in solution from which it is formed. Using micelle formation to disperse CBD forms a colloid not a solution.
Liposome – an artificially formed lipid droplet, small enough to form a relatively stable suspension in aqueous media and with potential use in drug delivery.
Derivatization – Derivatization techniques such as glycosylation are a technique used in chemistry which converts a chemical compound into a new product or derivative. Although the derivative might be more soluble than CBD it is not CBD!
In conclusion, unless CBD can be reduced to single solute molecules it is not water soluble!