Benzyl benzoate

• BPBenzyl Benzoate
• Ph. Eur.Benzyl Benzoate
• USP–NFBenzyl Benzoate

Benzoic acid benzyl ester; benzylis benzoas; benzyl benzenecarboxylate; phenylmethyl benzoate

Benzyl benzoate · [120-51-4]

UNII N863NB338G · PubChem CID 2345

C14H12O2 · 212.24

Solvent, humectant, Plasticiser

Typical concentrations: — · Dosage forms: Sterile (parenteral/ophthalmic), Semi-solid

Used as a solubiliser and co-solvent in oily intramuscular injections of steroids and other lipophilic drugs, where it may make up a large fraction (in some depot products around half) of the vehicle. It is also a plasticiser, a fixative in perfumes and a flavouring. As an active ingredient it is used topically (typically as a 25% application) for scabies and pediculosis.

A clear, colourless, oily liquid with a faint aromatic odour and a sharp, burning taste; it may form colourless crystals at low temperature.

Boiling point

≈ 323 °C

Melting/congealing point

≈ 17–20 °C; may crystallise when cool

Density

≈ 1.12 g/cm³ at 20 °C

Solubility

practically insoluble in water and glycerol; miscible with ethanol, chloroform, ether and fixed oils

Stable. Store in an airtight, well-filled container protected from light, and avoid exposure to excessive heat.

Incompatible with strong alkalis, which hydrolyse it, and with strong oxidising agents.

Made by esterifying benzoic acid with benzyl alcohol, or by the base-catalysed condensation of benzaldehyde (Tishchenko reaction); it also occurs naturally in balsams such as Peru and tolu balsam.

Hydrolysed in the body to benzoic acid and benzyl alcohol, which are excreted mainly as hippuric acid. Topical use may cause skin and eye irritation and occasionally contact sensitisation. Oily intramuscular vehicles containing benzyl benzoate have been associated with pulmonary oil microembolism and hypersensitivity reactions, and benzyl alcohol formed from it is a concern in neonates.

Observe normal precautions for the quantity handled. Gloves and eye protection are recommended; avoid contact with the eyes.

Included in the FDA Inactive Ingredient Database (intramuscular injections and topical preparations) and in parenteral and non-parenteral medicines licensed in Europe.

Benzoic acid; benzyl alcohol; ethyl oleate; castor oil (common co-vehicle).

Adding benzyl benzoate to vegetable oils greatly increases the solubility of many steroid esters, allowing smaller injection volumes; it also lowers the viscosity of oils such as castor oil, which eases injection.