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Sorbic Acid

    Synonyms: Disodium sulfite; exsiccated sodium sulfite; E221; natrii sulfis anhydricus; sulfurous acid disodium salt.

    Description: Sorbic acid is a tasteless, white to yellow-white crystalline powder with a faint characteristic odor.

    Chemical Name: (E,E)-Hexa-2,4-dienoic acid

    Antimicrobial preservative.

    • Sorbic acid is an antimicrobial preservative with antibacterial and antifungal properties used in pharmaceuticals, foods, enteral preparations, and cosmetics.

    • Generally, it is used at concentrations of 0.05–0.2% in oral and topical pharmaceutical formulations, especially those containing nonionic surfactants.

    • Sorbic acid is also used with proteins, enzymes, gelatin, and vegetable gums.

    • It has been shown to be an effective preservative for promethazine hydrochloride solutions in a concentration of 1 g/L.

    • Sorbic acid has limited stability and activity against bacteria and is thus frequently used in combination with other antimicrobial preservatives or glycols, when synergistic effects appear to occur;

    Sorbic acid is incompatible with bases, oxidizing agents, and reducing agents. Some loss of antimicrobial activity occurs in the presence of nonionic surfactants and plastics. Oxidation is catalyzed by heavy-metal salts. Sorbic acid will also react with sulfur-containing amino acids, although this can be prevented by the addition of ascorbic acid, propyl gallate, or butylhydroxytoluene.

    Sorbic acid is used as an antimicrobial preservative in oral and topical pharmaceutical formulations and is generally regarded as a nontoxic material. However, adverse reactions to sorbic acid and potassium sorbate, including irritant skin reactions and allergic hypersensitivity skin reactions (which are less frequent), have been reported.

    Observe normal precautions appropriate to the circumstances and quantity of material handled. Sorbic acid can be irritant to the skin, eyes, and respiratory system. Eye protection, gloves, and a dust mask or respirator are recommended.

    Calcium sorbate; potassium sorbate; sodium sorbate.