What it is
Industrial vitamin C production is a long-established two-stage process in which a sugar feedstock is converted by microbial fermentation to an intermediate, which is then chemically rearranged and lactonised to L-ascorbic acid. The crude product is recrystallised, dried and milled or granulated. Material intended for supplement and pharmaceutical use is tested against the USP or EP monograph, with optical rotation confirming the L-configuration.
Formulation considerations
Ascorbic acid is chemically reactive by design, and nearly every formulation decision around it is a stability decision. Its low solution pH will attack carbonates and bicarbonates, interact with alkaline minerals such as magnesium oxide, and accelerate the degradation of acid-labile co-vitamins. In a vitamin and mineral premix, physical separation through coating is the usual answer, since uncoated ascorbic acid sitting against iron or copper salts will degrade both. Coated grades using ethylcellulose or a lipid barrier substantially extend premix shelf life. Particle size drives the mechanical outcome: fine powder is cohesive and prone to bridging, while granular grades flow cleanly and compress without excessive lubricant.
Applications
The ingredient is used in tablets and capsules, effervescent tablets and sticks, dry beverage mixes, vitamin and mineral premixes, gummies and chewables, and in food systems where its reducing behaviour is wanted for colour and flavour protection. Multiple particle-size and coated grades are available in bulk quantities, with pricing on application.
Applications
- Tablets and capsules
- Effervescent powders and tablets
- Beverage and sachet premixes
- Vitamin and mineral premixes
- Gummies and chewables
- Food fortification and antioxidant use
Handling and storage
Store in sealed original packaging below 25°C in a dry, dark area with relative humidity under 55%. Typical shelf life is 36 months unopened. Ascorbic acid oxidises in the presence of moisture, oxygen, light and trace copper or iron, so keep liners sealed, avoid humid weighing rooms, and prefer stainless steel or lined contact surfaces over bare copper or brass.
Common questions
What is the difference between ascorbic acid and sodium ascorbate?
Ascorbic acid is the free acid, with a solution pH around 2.3 and roughly 100% vitamin C activity by weight. Sodium ascorbate is the neutral sodium salt, far gentler on acid-sensitive systems and on tooth enamel in chewables, but it carries sodium and about 89% vitamin C activity.
Which grade of ascorbic acid should be used for direct compression?
A granular or coated direct-compression grade, which flows and compacts far better than fine powder and reduces picking and sticking on tooling. Fine powder is better suited to wet granulation, dry beverage mixes and liquid applications.
Why does an ascorbic acid tablet or powder develop a yellow tinge?
Yellowing indicates oxidative degradation, usually driven by moisture plus oxygen and often catalysed by trace iron or copper. Coated grades, low-moisture excipients, oxygen barrier packaging and avoiding reactive metal contact all reduce the effect.
What documentation is supplied with each lot?
Each lot is supplied with a Certificate of Analysis against USP or EP monograph requirements, along with the Technical Data Sheet, Safety Data Sheet and allergen declaration.