In the BP 2009, the term ‘ethanol’ used without other qualification refers to ethanol containing 599.5% v/v of C2H6O. The term ‘alcohol’, without other qualification, refers to ethanol 95.1–96.9% v/v. Where other strengths are intended, the term ‘alcohol’ or ‘ethanol’ is used, followed by the statement of the strength. In the PhEur 6.0, anhydrous ethanol contains not less than 99.5% v/v of C2H6O at 208C. The term ethanol (96%) is used to describe the material containing water and 95.1–96.9% v/v of C2H6O at 208C.
Related Substances: Dehydrated alcohol; denatured alcohol; dilute alcohol; isopropyl alcohol.
- BP: Ethanol (96%)
- JP: Ethanol
- PhEur: Ethanol (96 per cent)
- USP: Alcohol
- Ethanolum (96 per centum); ethyl alcohol; ethyl hydroxide; grain alcohol; methyl carbinol.
Chemical Name and CAS Registry Number
- Ethanol [64-17-5]
Empirical Formula and Molecular Weight
- C2H6O 46.07
Functional Category: Antimicrobial preservative; disinfectant; skin penetrant; solvent.
Applications in Pharmaceutical Formulation or Technology
Ethanol and aqueous ethanol solutions of various concentrations are widely used in pharmaceutical formulations and cosmetics. Although ethanol is primarily used as a solvent, it is also employed as a disinfectant, and in solutions as an antimicrobial preservative. Topical ethanol solutions are used in the development of transdermal drug delivery systems as penetration enhancers. Ethanol has also been used in the development of transdermal preparations as a co-surfactant.
In the USP 32, the term ‘dehydrated alcohol’ refers to ethanol 599.5% v/v. The term ‘alcohol’ without other qualification refers to ethanol 94.9–96.0% v/v. In the JP XV, ethanol (alcohol) contains 95.1–96.9% v/v (by specific gravity) of C2H6O at 158C. In the Handbook of Pharmaceutical Excipients, the term ‘alcohol’ is used for either ethanol 95% v/v or ethanol 96% v/v. Alcohol is a clear, colorless, mobile, and volatile liquid with a slight, characteristic odor and burning taste.
- Antimicrobial activity Ethanol is bactericidal in aqueous mixtures at concentrations between 60% and 95% v/v; the optimum concentration is generally considered to be 70% v/v. Antimicrobial activity is enhanced in the presence of edetic acid or edetate salts. Ethanol is inactivated in the presence of nonionic surfactants and is ineffective against bacterial spores.
- Boiling point 78.158C
- Flammability Readily flammable, burning with a blue, smokeless flame.
- Flash point 148C (closed cup)
- Solubility: Miscible with chloroform, ether, glycerin, and water (with rise of temperature and contraction of volume).
- Specific gravity 0.8119–0.8139 at 208C
Method of Manufacture
Ethanol is manufactured by the controlled enzymatic fermentation of starch, sugar, or other carbohydrates. A fermented liquid is produced containing about 15% ethanol; ethanol 95% v/v is then obtained by fractional distillation. Ethanol may also be prepared by a number of synthetic methods.