Sodium ascorbate

• BPSodium Ascorbate
• Ph. Eur.Sodium Ascorbate
• USP–NFSodium Ascorbate

Ascorbate sodium; L-ascorbic acid monosodium salt; natrii ascorbas; vitamin C sodium; E301

Sodium (2R)-2-[(1S)-1,2-dihydroxyethyl]-4-hydroxy-5-oxo-2H-furan-3-olate (monosodium L-ascorbate) · [134-03-2]

UNII S033EH8359 · PubChem CID 23667548

C6H7NaO6 · 198.11

Antioxidant, chelating agent

Typical concentrations: — · Dosage forms: Liquid, Sterile (parenteral/ophthalmic)

Sodium ascorbate is used as an antioxidant in oral, parenteral and topical preparations and foods, usually at low concentrations (of the order of 0.01–0.1% w/v), and as a source of vitamin C. Because its solutions are close to neutral, it is preferred to ascorbic acid where an acidic pH is undesirable, for example in injections and neutral oral liquids. It is also used to enhance iron absorption and as a meat-curing adjunct in foods.

A white or very faintly yellow crystalline powder, odourless or almost odourless, with a pleasant saline taste. It darkens gradually on exposure to light. 1 g of sodium ascorbate corresponds to about 0.89 g of ascorbic acid.

pH

7.0–8.0 (10% w/v aqueous solution)

Specific rotation

+103° to +108° (10% w/v aqueous solution)

Melting point

decomposes at about 218 °C

Solubility

freely soluble in water; very slightly soluble in ethanol; practically insoluble in ether and chloroform

Reasonably stable in dry air, but darkens on exposure to light and moisture. Aqueous solutions oxidise readily, especially at alkaline pH and in the presence of traces of copper or iron, and should be prepared fresh or protected with an inert gas and a chelating agent. Store in an airtight, light-resistant container in a cool, dry place.

Incompatible with oxidising agents, heavy metal ions (especially copper and iron) and alkalis. It is a reducing agent and may reduce or react with other formulation components; in the presence of benzoate it can contribute to the formation of traces of benzene.

Prepared by dissolving ascorbic acid in water and neutralising with an equivalent amount of sodium bicarbonate or carbonate; the sodium ascorbate is precipitated by adding an alcohol such as isopropanol, then filtered and dried.

Generally regarded as non-toxic and non-irritant at the concentrations used as an antioxidant. Very large doses of vitamin C may cause gastrointestinal upset, and the sodium content should be considered for patients on sodium-restricted diets.

Observe normal precautions for the quantity handled. Eye protection and gloves are recommended.

GRAS listed. Accepted as a food additive in Europe (E301). Included in the FDA Inactive Ingredient Database (oral preparations and injections) and in medicines licensed in Europe.

Ascorbic acid; ascorbyl palmitate; calcium ascorbate; erythorbic acid; sodium erythorbate.

Its antioxidant action depends on being preferentially oxidised, so it is consumed during storage; the remaining content should be monitored in stability studies. A chelating agent such as disodium edetate and nitrogen purging greatly slow its degradation in solution.