Food additives Europe numbers: E1510
Functional Category
Antimicrobial preservative; disinfectant; skin penetrant; solvent
Applications in Pharmaceutical Formulation
Ethanol and aqueous ethanol solutions of various concentrations (see Sections 8 and 17) are widely used in pharmaceutical formulations and cosmetics; see Table I. Although ethanol is primarily used as a solvent, it is also employed as a disinfectant, and in solutions as an antimicrobial preservative.(1,2) Topical ethanol solutions are used in the development of transdermal drug delivery systems as penetration enhancers.(3–10) Ethanol has also been used in the development of transdermal preparations as a co-surfactant.(11–13)
Description
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 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.
Stability and Storage Conditions
Aqueous ethanol solutions may be sterilized by autoclaving or by filtration and should be stored in airtight containers, in a cool place
Incompatibilities
In acidic conditions, ethanol solutions may react vigorously withoxidizing materials. Mixtures with alkali may darken in colorowing to a reaction with residual amounts of aldehyde. Organic salts or acacia may be precipitated from aqueous solutions or dispersions. Ethanol solutions are also incompatible with aluminumcontainers and may interact with some drugs