What it is
Sodium hyaluronate is a linear polysaccharide built from repeating disaccharide units of glucuronic acid and N-acetylglucosamine. Commercial production now runs almost entirely through microbial fermentation, which gives better control of chain length than tissue extraction and avoids animal-derived input entirely. After fermentation the polymer is recovered, purified to remove protein and endotoxin, precipitated and dried to a white powder.
Formulation considerations
Molecular weight is the whole conversation. Because viscosity scales steeply with chain length, a 1% solution of a 1.5 MDa grade and a 1% solution of a 10 kDa grade are entirely different materials to work with: one is a thick gel, the other is close to water. Specifying a numerical molecular weight range rather than a descriptor such as “high” or “low” is the only reliable way to get consistent batches.
Hydration technique follows from that. High molecular weight powder wets slowly and will encase dry material inside a gel skin if added too quickly, so slow addition into vigorous agitation is standard practice. In solution, the polymer is sensitive to extremes of pH and to oxidising conditions, both of which cut chains and reduce viscosity, and electrolytes depress viscosity by screening charge along the backbone. Adding salts after full hydration rather than before avoids surprises.
Applications
Topical serums and creams use the higher molecular weight grades for viscosity and film character. Oral capsules, tablets, beverages and drink mixes generally use low molecular weight or hydrolysed grades for faster dissolution and lower viscosity contribution. Available in bulk quantities, with pricing on application.
Applications
- Serums, creams and cosmetic formulations
- Oral capsules and tablets
- Beverages and liquid formats
- Powder sachets and drink mixes
Handling and storage
Store sealed below 25 degrees Celsius in a dry environment, away from light. The powder is markedly hygroscopic and will absorb atmospheric moisture, which causes clumping and makes accurate weighing difficult, so containers should be resealed immediately and opened in a low-humidity area. Typical shelf life is 36 months from manufacture in unopened packaging. Avoid exposure to strong oxidising agents and to extremes of pH in solution, both of which promote chain scission and loss of viscosity.
Common questions
Which molecular weight of hyaluronic acid should I use?
High molecular weight grades above roughly 1 MDa build viscosity and form films, which suits topical serums and creams. Low molecular weight and hydrolysed grades dissolve faster, give much lower viscosity at the same concentration and are generally preferred for oral and beverage formats. The grade should be fixed by target viscosity and solubility behaviour.
Is your hyaluronic acid animal derived?
No. The material is produced by microbial fermentation rather than from animal tissue, and a non-animal origin declaration is supplied with each lot for formulators who need it on file.
How do I dissolve hyaluronic acid powder without lumps?
Sprinkle the powder slowly onto the surface of well-agitated water rather than adding it as a bolus, and allow time for full hydration before adjusting pH or adding electrolytes. High molecular weight grades hydrate slowly and will form gel lumps if wetted too fast.
What assay and purity figures are typical?
Assay is 95% minimum on a dried basis with glucuronic acid at 45% minimum and protein held to 0.1% maximum. All figures are confirmed on the lot Certificate of Analysis.