Name: Sodium Acetate
CAS No: Sodium acetate anhydrous [127-09-3], Sodium acetate trihydrate [6131-90-4]
BP: Sodium Acetate Trihydrate JP: Sodium Acetate Hydrate PhEur: Sodium Acetate Trihydrates USP: Sodium Acetate
Acetic acid, sodium salt; E262; natrii acetas trihydricus; sodium ethanoate
Sodium acetate anhydrous [127-09-3], Sodium acetate trihydrate [6131-90-4]
C2H3NaO2 82.0 (for anhydrous) C2H3NaO23H2O 136.1 (for trihydrate) Note that the trihydrate is the material described in the JP XV, PhEur 6.0 and USP 32, although the PhEur 6.0 is the only pharmacopeia that makes this explicit with the title of the monograph.
Sodium acetate is used as part of a buffer system when combined with acetic acid in various intramuscular, intravenous, topical, ophthalmic, nasal, oral, otic, and subcutaneous formulations. It may be used to reduce the bitterness of oral pharmaceuticals.(1) It can be used to enhance the antimicrobial properties of formulations; it has been shown to inhibit the growth of S. aureus and E. coli, but not C. albicans in protein hydrolysate solutions.(2) It is widely used in the food industry as a preservative.(3) Sodium acetate has also been used therapeutically for the treatment of metabolic acidosis in premature infants,(4,5) and in hemodialysis solutions.(6,7)
Sodium acetate occurs as colorless, transparent crystals or a granular crystalline powder with a slight acetic acid odor.
See Table I.
Acidity/alkalinity pH = 7.5–9.0 (5% w/v aqueous solution) Hygroscopicity The anhydrous and trihydrate sodium acetate are hygroscopic. Solubility Soluble 1 in 0.8 in water, 1 in 20 in ethanol (95%). Melting point 588C for trihydrate; 3248C for anhydrous.(8) Specific gravity 1.53
Sodium acetate should be stored in airtight containers.
Sodium acetate reacts with acidic and basic components. It will react violently with fluorine, potassium nitrate, and diketene.
Sodium acetate is prepared by neutralization of acetic acid with sodium carbonate.
Sodium acetate is widely used in cosmetics, foods, and pharmaceutical formulations (see Section 18), and is generally regarded as a nontoxic and nonirritant material. A short-term feeding study in chickens with a diet supplemented with 5.44% sodium acetate showed reduced growth rates that were attributed to the sodium content.(9) Sodium acetate is poisonous if injected intravenously, is moderately toxic by ingestion, and is an irritant to the skin and eyes.(10) LD50 (rat, oral): 3.53 g/kg(10) LD50 (mouse, IV): 0.38 g/kg(11) LD50 (mouse, SC): 8.0 g/kg(10
Observe normal precautions appropriate to the circumstances and quantity of material handled. Sodium acetate is a mild skin and eye irritant; gloves and eye protection are recommended. On exposure, wash eyes and skin with large amounts of water. Inhalation of dust may cause pulmonary tract problems. When heated to decomposition, sodium acetate emits toxic fumes of NaO2. (10)
GRAS listed. Accepted as a food additive in Europe. Included in the FDA Inactive Ingredients Database (injections, nasal, otic, ophthalmic, and oral preparations).
Sodium acetate was shown to enhance aqueous humor to plasma concentration ratio of timolol by about 20-fold in an ophthalmic monoisopropyl PVM-MA matrix system, presumably by decreasing systemic absorption.(12) Sodium acetate has also been used experimentally in matrix tablet formulations, where it increased the effect of carbomer as a sustained release matrix.(13) A specification for sodium acetate is contained within the Food Chemicals Codex (FCC).(14) The PhEur 6.0 also contains a monograph on sodium acetate [1-11C] injection under Radiopharmaceutical Preparations. The EINECS number for sodium acetate is 204-823-8. The PubChem Compound ID (CID) for sodium acetate trihydrate is 23665404