Issue 12 - Compounding news: what fits in a capsule?

Updated 3 weeks ago by Lynn Joels

We have had a few questions from practitioners recently about how much active ingredient will fit into a capsule. So we thought it would be worth sharing the answer here with you all.

We use 3 sizes of capsules for compounding at Natural Chemist, they are known by a standardised numbering system as 3, 0 and 00. #3 is the smallest that we use, and #00 the largest.

  • Capsule length
    • #3 capsules - 16mm
    • #0 - 22mm
    • #00 are 23mm
  • Capsule volume
    • #3 capsules volume of 0.3mL
    • #0 volume of 0.68mL
    • #00 volume of 1.37mL

Active ingredient weight – The amount of powder in mg that each of the capsules can hold will depend on the density of the active ingredient. Most active ingredients have a density in the range of 0.6-1.2g/mL. From this we can calculate that the largest capsule will hold approximately 800 to 1600mg of powder.

Elemental compared to total salt weight – When working out the weight of the prescribed active ingredients it is also very important to consider the weight of the molecule that the active ingredient is bound to. Let's use magnesium as an example:

  • Magnesium glycinate is 20% magnesium, whereas magnesium chloride is 25% magnesium, because the inactive part of the different molecules has a different weight. This means that when you prescribe 300mg magnesium (as glycinate) we need to put in 1500 mg of magnesium glycinate. This will of course take up much more space in the capsule than if we use magnesium chloride, which would only require 1200mg to give you 300mg dose of magnesium.

The bottom line - if you are prescribing a formula with a total powder volume of more than 1-2g it is going to be difficult to fit it into a capsule, so it may be better to consider prescribing a powder.

Please do not hesitate to call or email if you would like to talk about this in more detail or you have a particular formula in mind.


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