Moisture protection
The problem
Moisture is the quietest of the four stressors and often the most expensive. A hygroscopic active draws water out of the air and out of its neighbours in the blend. The powder cakes and stops flowing, so capsule-fill weight drifts. Activity falls. And the water it has drawn in accelerates every other degradation route in the formulation — oxidation, hydrolysis, interaction — so a moisture problem usually presents as something else.
It is also the failure mode most sensitive to where the product is sold. A blend that is stable in Northern Europe can fail in a humid market within months.
Why the conventional approach fails
Desiccants in the pack help, but they protect the headspace rather than the particle, and they are consumed. Tighter packaging raises cost and does nothing once the pack is opened by the consumer. Neither addresses the fact that the hygroscopic ingredient is drawing moisture from within the blend itself.
How NexaGens addresses it
A moisture barrier applied at the particle level, so the protection travels with the ingredient rather than with the pack. For choline bitartrate this is combined with taste and odour barriers, because the same active carries all three problems at once and solving one at a time is wasteful.
Relevant products
| Product | Assay | Combined protection | Status |
|---|---|---|---|
| Choline Bitartrate Taste- and Odour-Masked IR Pellets | 50% w/w (nominally 20% choline) | Moisture, taste, odour | Qualified |
| NADH Enteric-Protected Pellets | 20% w/w | Moisture, oxygen, gastric acid | Qualified |
Enzyme and probiotic pellets, where moisture protection is decisive for retained activity, are in development and not currently supplied.
What to specify, and how to test it
- A moisture-uptake isotherm — mass gain against relative humidity at a stated temperature, protected versus unprotected. A single “moisture protected” statement is not specifiable.
- Water activity (aw) at release, not just percentage moisture. Water activity, not total water, drives degradation and microbial risk.
- Caking and flow behaviour after conditioning at a defined humidity — angle of repose or Carr index before and after.
- Assay retention after humidity challenge, alongside the physical measurements.
- The humidity condition you actually ship into. Ask for data at 75% RH if you sell into humid markets; European ambient data will not predict it.
- Barrier integrity after blending — a moisture barrier damaged during processing protects nothing.
For the NexaGens products above, uptake test design and acceptance criteria form part of the product specification, and each production batch is supplied with a batch-specific certificate of analysis.
Next steps
See the moisture-protected pellets · Discuss a humid-market formulation