Sublingual Absorption of Colloidal Silver

Reprinted from Colloidal Silver Forum with permission.

Some colloidal silver sites say colloidal silver can be absorbed by holding it under the tongue.  Science says otherwise.

Anyone who has had sub lingual nitroglycerin, or put DMSO on their skin will attest to the fact that some things will quickly penetrate skin and oral mucosa. But will ionic or colloidal silver?

Many sites will tell you that you can take colloidal silver (ionic or metallic) via holding it under your tongue. However, the consensus of pharmaceutical sites does not support this.

For sublingual absorption to occur:

The drug must be highly concentrated
The drug must be fat/oil soluble
If ionic, the drug must have low pH (acid)
The substance must weigh less than 10,000 daltons1,3

Neither ionic or colloidal silver can be considered as being highly concentrated.

Since a silver nanoparticle of 14nm diameter weighs about 6.8 million daltons3, absorption of silver nanoparticles would not be possible.

Neither ionic silver or metallic silver is fat soluble, which also points to the lack of sub lingual absorption. Neither one is very acidic either.

Quotes from: http://www.ijppsjournal.com/Vol3Suppl2/1092.pdf

The absorption potential of oral mucosa is influenced by the lipid solubility and therefore the permeability of the solution (osmosis); the ionization (pH); and the molecular weight of the substances. For example, absorption of some drugs via oral mucosa is shown to increase when carrier pH is lowering (more acidic) and decrease with a raising of pH (more alkaline)
Lipophilicity of drug: For a drug to be absorbed completely through sublingual route, the drug must have slightly higher lipid solubility than that required for GI absorption is necessary for passive permeation.

Since ionic silver binds strongly to normal human cells because of its electrical charge, the ionic silver will be trapped inside healthy cells before entering the bloodstream.

Quote

Binding to oral mucosa: Systemic availability of drugs that bind to oral mucosa is poor.1

Since the MIC2 of silver for common bacteria is at least 2ppm which for most people means 10 mg of silver (1 pint of 20 ppm colloidal silver), it is certainly not possible to absorb enough silver by the sub-lingual route even if it were highly absorbable by that route. Therefore, any perceived benefit is very likely to be caused by the placebo effect.

See also “Enhancement in Drug Delivery” by Elka Touitou and Brian W. Barry for a more detailed discussion.

So,neither colloidal silver nor ionic silver can be beneficially absorbed under the tongue.

1) https://learn.pharmacy.unc.edu/pharmacopedia/pharmaceutics411/index.php/Buccal_and_Sublingual
2) Minimum Inhibitory Concentration. The amount necessary to inhibit bacterial growth
3) Dalton, the total of the atomic weights of all the elements in a substance. For example, a water molecule weighs 18 daltons.