What it is
Picolinic acid is a pyridine carboxylic acid, and when two molecules of it coordinate a single zinc ion the result is a neutral, tightly bound complex. Manufacture involves reacting a soluble zinc salt with picolinic acid or its sodium salt under controlled pH, after which the sparingly soluble chelate precipitates and is washed, dried and milled. Washing matters commercially, since residual free picolinic acid and residual chloride are the two impurities most often queried on specification.
Formulation considerations
Low solubility is the defining practical characteristic and it cuts both ways. It is why the chelate contributes almost no metallic or astringent note to a chewable or a capsule, and it is also why beverage applications are not a natural fit. In tablets the fine, cohesive powder benefits from pre-blending with a portion of the filler before the main mix, and the low inclusion rate relative to total mass means blend uniformity should be verified by assay rather than assumed. The complex is stable to the heat and pressure of compression and is not strongly reactive toward other premix components, although proximity to high levels of ascorbic acid or ferrous salts should still be assessed for the premix as a whole.
Applications
Typical uses are zinc tablets and capsules, multivitamin and mineral tablets, premixes, chewables, and multi-ingredient dry-blend supplement formats. Available in bulk quantities, with pricing on application.
Applications
- Tablets and capsules
- Vitamin and mineral premixes
- Multivitamin formulations
- Multi-ingredient supplement blends
- Sachets and powder blends
- Chewable tablets
Handling and storage
Keep in sealed original packaging below 25°C in a dry store with relative humidity under 60%, away from direct light. Typical shelf life is 36 months unopened. The chelate is stable as a dry solid and only slightly hygroscopic, but the fine particle size makes it dusty and cohesive, so controlled charging and a stepwise pre-blend improve uniformity at low inclusion rates.
Common questions
How much elemental zinc does zinc picolinate contain?
Typically 20.0% to 21.5% by weight, so around 5 g of the chelate supplies about 1 g of elemental zinc. Formulate to the lot figure confirmed on the Certificate of Analysis rather than to the theoretical value.
How does zinc picolinate differ from zinc citrate or zinc gluconate in formulation?
Picolinate carries a higher elemental zinc load per gram than gluconate and roughly similar to citrate, and it is markedly less soluble than either. Its advantages in a solid dosage form are a neutral taste and good dry stability; its limitation is that it is not a practical choice for a clear beverage.
Is zinc picolinate suitable for a drink powder?
Only with caveats. Water solubility is low, so it will largely remain suspended rather than dissolved, which can read as sediment in a clear drink. Citrate or a soluble chelate is usually specified for beverage work.
What documentation is supplied with each lot?
A lot-specific Certificate of Analysis reporting assay, elemental zinc, free picolinic acid and heavy metals is issued with every consignment, together with the Technical Data Sheet and Safety Data Sheet.