Alcohol (ethanol)

• BPEthanol (96 per cent)
• JPEthanol
• Ph. Eur.Ethanol (96 per cent)
• USP–NFAlcohol

Ethanol; ethyl alcohol; ethyl hydroxide; grain alcohol; methyl carbinol

Ethanol · [64-17-5]

UNII 3K9958V90M · PubChem CID 702

C2H6O · 46.07

Solvent, humectant, Antimicrobial preservative

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

Ethanol is one of the most widely used solvents and co-solvents in oral solutions, elixirs, tinctures, topical products and some injections, and is the usual solvent for extraction of plant materials. It is used as a granulating fluid, a solvent in film coating, a penetration enhancer in transdermal products and as an antimicrobial preservative. Typical concentrations: antimicrobial preservative ≥ 10% v/v; topical antiseptic and disinfectant 60–90% v/v; extraction up to about 85%; other uses as needed for solubility.

A clear, colourless, mobile and volatile liquid with a slight, characteristic odour and a burning taste. It burns with a blue, smokeless flame.

Strength

ethanol (96%) / USP Alcohol contains about 94.9–96.0% v/v (USP) or 95.1–96.9% v/v (Ph. Eur.) ethanol; anhydrous grades ≥ 99.5% v/v

Boiling point

≈ 78 °C

Density

≈ 0.81 g/cm³ at 20 °C (96% grade); ≈ 0.79 g/cm³ (anhydrous)

Flash point

about 13–14 °C (closed cup); highly flammable

Solubility

miscible with water, glycerol, ether, chloroform and most organic solvents

Stable. Store in an airtight container in a cool place away from heat and ignition sources. Anhydrous ethanol is hygroscopic and takes up water from the air. Aqueous ethanol mixtures can be sterilised by filtration.

Reacts vigorously with strong oxidising agents. Mixtures with alkalis may darken because of oxidation of residual aldehydes. Ethanol precipitates many gums, proteins and inorganic salts (for example acacia and some electrolytes) from aqueous solution.

Made by fermentation of sugars or starch-derived glucose with yeast followed by fractional distillation, or synthetically by catalytic hydration of ethylene. Dehydrated grades are obtained by azeotropic or molecular-sieve drying.

At the levels used in most medicines ethanol is safe for adults, but it is a central nervous system depressant and its content must be considered in products for children, pregnant women, people with alcohol dependence or liver disease, and in combination with other CNS depressants; EU labelling rules apply to medicines containing it. Applied to skin it can cause dryness and irritation, particularly on broken skin.

Highly flammable: use with adequate ventilation, away from flames and sparks, with earthed equipment. Eye protection and gloves are recommended. Ethanol vapour can form explosive mixtures with air.

GRAS listed. Classified as an ICH Q3C Class 3 residual solvent. Included in the FDA Inactive Ingredient Database (dental, inhalation, injections, nasal, ophthalmic, oral, rectal, topical and transdermal preparations) and in parenteral and non-parenteral medicines licensed in Europe.

Dehydrated alcohol (anhydrous ethanol); diluted alcohol; denatured alcohol; isopropyl alcohol.

When ethanol and water are mixed the volume contracts and heat is released, so strengths should be stated clearly as % v/v or % w/w. In many countries undenatured ethanol is subject to excise control, and manufacturers must keep records of its use.