Ascorbyl palmitate

• BPAscorbyl Palmitate
• Ph. Eur.Ascorbyl Palmitate
• USP–NFAscorbyl Palmitate

Ascorbic acid palmitate; ascorbylis palmitas; L-ascorbyl 6-palmitate; vitamin C palmitate; E304

(2S)-2-[(2R)-3,4-Dihydroxy-5-oxo-2,5-dihydrofuran-2-yl]-2-hydroxyethyl hexadecanoate · [137-66-6]

UNII QN83US2B0N · PubChem CID 54680660

C22H38O7 · 414.54

Antioxidant, chelating agent

Typical concentrations: — · Dosage forms: Semi-solid, Solid, Liquid

Used as an antioxidant for oils, fats, oily preparations, emulsions, ointments and oral and topical formulations, usually at about 0.01–0.2% w/v. It is frequently combined with alpha tocopherol, with which it acts synergistically, and is also used in foods and cosmetics.

A white to yellowish-white powder with a characteristic odour.

Melting point

≈ 107–117 °C

Solubility

freely soluble in ethanol and methanol; slightly soluble in vegetable oils; very slightly soluble in water

Appearance

white to yellowish-white powder

Lipophilicity

amphiphilic: the palmitate chain gives fat solubility while the ascorbyl group retains antioxidant activity

Stable in the dry state but slowly oxidised by air and light, especially in solution; trace metals accelerate its degradation. Store in an airtight container protected from light in a cool, dry place.

Incompatible with oxidising agents; metal ions such as copper and iron catalyse its oxidation.

Prepared by esterifying ascorbic acid with palmitic acid (or a palmitic acid derivative) in the presence of a strong acid catalyst, such as concentrated sulfuric acid, followed by purification by recrystallisation.

Hydrolysed in the gut to ascorbic acid and palmitic acid, both normal dietary constituents, and regarded as non-toxic and non-irritant. JECFA has allocated a group ADI of 0–1.25 mg/kg body weight for ascorbyl palmitate and ascorbyl stearate.

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

GRAS listed. Accepted as a food additive in Europe (E304). Included in the FDA Inactive Ingredient Database (oral and topical preparations) and in non-parenteral medicines licensed in Europe.

Ascorbic acid; ascorbyl stearate; sodium ascorbate; alpha tocopherol.

Because its solubility in oils is limited, it is often first dissolved in a small amount of ethanol or warm oil before being added to the lipid phase. It is particularly effective at protecting oils rich in polyunsaturated fatty acids.