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Sodium Benzoate

    Synonyms: Benzoic acid sodium salt; benzoate of soda; E211; natrii benzoas; natrium benzoicum; sobenate; sodii benzoas; sodium benzoic acid.

    Description: Sodium benzoate occurs as a white granular or crystalline, slightly hygroscopic powder. It is odorless, or with faint odor of benzoin and has an unpleasant sweet and saline taste.

    Chemical Name: Sodium benzoate

    Antimicrobial preservative; tablet and capsule lubricant.

    • Sodium benzoate is used primarily as an antimicrobial preservative in cosmetics, foods, and pharmaceuticals.

    • It is used in concentrations of 0.02–0.5% in oral medicines, 0.5% in parenteral products, and 0.1–0.5% in cosmetics.

    • The usefulness of sodium benzoate as a preservative is limited by its effectiveness over a narrow pH range.

    • Sodium benzoate is used in preference to benzoic acid in some circumstances, owing to its greater solubility.

    • However, in some applications it may impart an unpleasant flavor to a product.

    • Sodium benzoate has also been used as a tablet lubricant at 2–5% w/w concentrations.

    • Solutions of sodium benzoate have also been administered, orally or intravenously, in order to determine liver function.

    Ingested sodium benzoate is conjugated with glycine in the liver to yield hippuric acid, which is excreted in the urine. Symptoms of systemic benzoate toxicity resemble those of salicylates. Whereas oral administration of the free-acid form may cause severe gastric irritation, benzoate salts are well tolerated in large quantities: e.g. 6 g of sodium benzoate in 200 mL of water is administered orally as a liver function test.

    Ingested sodium benzoate is conjugated with glycine in the liver to yield hippuric acid, which is excreted in the urine. Symptoms of systemic benzoate toxicity resemble those of salicylates. Whereas oral administration of the free-acid form may cause severe gastric irritation, benzoate salts are well tolerated in large quantities: e.g. 6 g of sodium benzoate in 200 mL of water is administered orally as a liver function test.

    Observe normal precautions appropriate to the circumstances and quantity of material handled. Sodium benzoate may be irritant to the eyes and skin. Eye protection and rubber or plastic gloves are recommended

    Benzoic acid; potassium benzoate.