Chemical Properties
Sodium propionate occurs as colorless transparent crystals or as a
granular, free-flowing, crystalline powder. It is odorless, or with a
slight characteristic odor, and is deliquescent in moist air. Sodium
propionate has a characteristic, slightly cheeselike taste, although
by itself it is unpalatable.
Uses
Pharmaceutic aid (preservative).
Uses
Sodium Propionate Hydrate is a food preservative used for its antifungal ability towards grain products.
Production Methods
Sodium propionate is prepared by the reaction of propionic acid
with sodium carbonate or sodium hydroxide.
Pharmaceutical Applications
As an excipient, sodium propionate is used in oral pharmaceutical
formulations as an antimicrobial preservative. Like propionic acid,
sodium propionate and other propionic acid salts are fungistatic
and bacteriostatic against a number of Gram-positive cocci.
Propionates are more active against molds than is sodium benzoate,
but have essentially no activity against yeasts.
Therapeutically, sodium propionate has been used topically in
concentrations up to 10% w/w alone or in combination with other propionates, caprylates, or other antifungal agents, in the form of
ointments or solutions for the treatment of dermatophyte infections.
Eye drops containing 5% w/v sodium propionate have also been
used.
In food processes, particularly baking, sodium propionate is
used as an antifungal agent; it may also be used as a flavoring agent
in food products. In veterinary medicine, sodium propionate is used
therapeutically as a glucogenic substance in ruminants.
Safety
Sodium propionate and other propionates are used in oral
pharmaceutical formulations, food products, and cosmetics. The
free acid, propionic acid, occurs naturally at levels up to 1% w/w in
certain cheeses.
Following oral consumption, propionate is metabolized in
mammals in a manner similar to that of fatty acids. Toxicity studies
in animals have shown sodium propionate and other propionates to
be relatively nontoxic materials.(2,3) In veterinary medicine, sodium
propionate is used as a therapeutic agent for cattle and sheep.
In humans, 6 g of sodium propionate has been administered
daily without harm.(2) However, allergic reactions to propionates
can occur.
LD50 (mouse, oral): 6.33 g/kg
LD50 (mouse, SC): 2.1 g/kg
LD50 (rabbit, skin): 1.64 g/kg
storage
Sodium propionate is deliquescent and should therefore be stored in
an airtight container in a cool, dry place.
Incompatibilities
Incompatibilities for sodium propionate are similar to those of other
weak organic acids.
Regulatory Status
GRAS listed. Accepted for use as a food additive in Europe. In
cheese products, propionates are limited to 0.3% w/w concentration;
a limit of 0.32% w/w is applied in flour and white bread rolls,
while a limit of 0.38% w/w is applied in whole wheat products.
Included in the FDA Inactive Ingredients Database (oral
capsules, powder, suspensions, and syrups). Included in nonparenteral
medicines licensed in the UK. Included in the Canadian List
of Acceptable Non-medicinal Ingredients.
