Diving Into Water Soluble Technologies

Diving into Water Soluble CBD Technologies

By Mile High Labs Formulations Manager, Scott Miller

CBD is hydrophobic, or water-fearing, which makes it almost completely insoluble in water. To infuse CBD into a beverage or any aqueous product, different techniques need to be employed to prevent CBD from just floating on the surface as a powder. 

At Mile High Labs, we use a unique nano-emulsification process to create our Water Soluble Liquids. One of our goals is to provide education not only on our own processes, but on the processes of the CBD industry as a whole. The techniques covered in this article ultimately accomplish the same goal of making CBD dispersible in a water-based product. But can any of them be considered truly “water soluble” and what are the pros and cons of each? Let’s take a look.

Esterification

CBD can be chemically modified to form esters, which increases its solubility in water. This technique is commonly used with pharmaceutical active ingredients, but requires significant chemical treatment of the base molecule, along with further extraction and purification to remove residual chemicals. Esterified pharmaceuticals are often referred to as “prodrugs” because the active form is created when the ester is lost. Esterified CBD dissolved in water forms a solution.

Pros:

  • The only “true” water soluble CBD – all other technologies are some form of suspension in water
  • Solutions will be clear and colorless
  • May be applied to a dry product (coffee, tea, etc.)
  • May not require preservation
  • May be dried into a powdered product

Cons:

  • Considered synthetic and a “new chemical entity” which requires significant development to ensure safety and effectiveness
  • May be incompatible with certain beverage formulations due to trans-esterification reactions and other chemistry occurring in the product
  • Chemical reagents and residual solvents make this approach the least “clean label”

Stabilized Suspension

In stabilized suspension, CBD is present in water as a nano-sized suspended solid. It’s further stabilized using a few different techniques.

Charge stabilization: A negatively or positively charged chemical that associates with the CBD particles, preventing them from recombining to form larger particles

Encapsulation: A chemical that forms a film around the CBD particles, preventing them from recombining to form larger particles, also referred to as steric stabilization

Gelling Agent / Suspending Agent: A chemical that increases the viscosity of water and limits movement of the suspended CBD particles, preventing them from floating, sedimenting or recombining to form larger particles, also referred to as steric stabilization

Pros:

  • “Clean label” and zero calorie formulation
  • Fewer ingredients and lower concentrations impact flavor less than emulsions or liposomes
  • Suspended solid particles are unlikely to react with chemicals in the beverage formulation
  • May not require preservation
  • May be applied to a dry product (coffee, tea, etc.)
  • May be dried into a powdered product

Cons:

  • Suspensions are the most difficult to maintain over long shelf lives because the suspended solids may settle
  • Products containing other suspended solids may cause the CBD particles to agglomerate
  • Nano-sized solid particles may not be compatible with carbonated products due to nucleation
  • Requires high energy to create nano-sized particles, either high pressure or sonication

Nano-Emulsified Oil (MHL’s Water Soluble Liquid)

In the nano-emulsification process, CBD is dissolved in a suitable carrier oil which remains liquid at a wide temperature range, including room temperature. The mixture of CBD and oil is blended with emulsifiers. These work at the interface of the oil and water to stabilize the droplet (emulsifiers are also referred to as surfactants, i.e. Surface Active Agents). This oil phase is added to water and mixed to form a coarse emulsion (stabilized droplets of oil dispersed in water). The coarse emulsion is then nano-emulsified with a high pressure emulsifier to create very small droplets (~250nm) which are stable over long periods of time without agglomerating (recombining), creaming (floating to the top) or sedimenting (sinking to the bottom).

Pros:

  • “Clean label” formulation (if naturally preserved)
  • Nano-emulsions are extremely stable and do not interact chemically with the beverage formulation
  • Emulsion-based formula will blend with almost any liquid or semisolid product (honey or topical)
  • High absorption in the body

Cons:

  • Requires high energy to create the nano-sized oil droplets, either high pressure emulsification or sonication
  • Does not always produce a clear, colorless solution
  • Products containing other suspended solids may cause the oil droplets to agglomerate
  • Cannot be applied to a dry product

Micelle

A micelle is a spherical vesicle created using phospholipids or other surfactants.  The outer surface of the vesicle is composed of hydrophilic (water-loving) head groups while the inside of the vesicle is composed of the hydrophobic (water-fearing) tail groups.  It is possible to contain CBD in the inside of a micelle which will remain stable when dispersed in water.

The difference between a micelle and an emulsified oil droplet is the presence of a carrier oil.

Pros:

  • “Clean label” and oil-free formulation (if naturally preserved)
  • High absorption in the body

Cons:

  • Products containing other suspended solids may cause the CBD particles to agglomerate 
  • May require high energy to create stable micelles, high pressure emulsification or sonication
  • Does not produce a clear, colorless solution
  • Cannot be applied to a dry product

Liposome

A liposome is a spherical vesicle created by a phospholipid bilayer with the center consisting of water or an aqueous solution. They are commonly used for drug delivery purposes since the lipid bilayer is very similar to that found in human cells. Drugs can be contained either in the aqueous center of the liposome (hydrophilic molecules) or within the lipid bilayer (hydrophobic molecules like CBD).  

Liposomes are similar to micelles and are usually composed of similar ingredients.

Pros:

  • “Clean label” and oil-free formulation (if naturally preserved)
  • Possible to combine CBD with water soluble actives that might otherwise be incompatible (caffeine, vitamins, etc.)
  • High absorption in the body

Cons:

  • Requires high energy to create the liposome containing CBD, typically high pressure emulsification
  • Cannot be applied to a dry product

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Scott Miller is an experienced chemist with expertise in formulation and analytical method development. Prior to joining Mile High Labs, he worked as a topical formulation scientist in the pharmaceutical industry and as a certified chromatography and mass spectrometry service engineer for multiple vendors. Scott leads Mile High’s consumer product formulation efforts.

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