International Numbering System (INS) for Food Additives: 214
Food additives Europe numbers: E214
Functional Category
Antimicrobial preservative.
Applications in Pharmaceutical Formulation
Ethylparaben is widely used as an antimicrobial preservative in cosmetics,(1) food products, and pharmaceutical formulations. It may be used either alone or in combination with other paraben esters or with other antimicrobial agents. In cosmetics it is one of the most frequently used preservatives. The parabens are effective over a wide pH range and have a broad spectrum of antimicrobial activity, although they are most effective against yeasts and molds; see Section 10. Owing to the poor solubility of the parabens, paraben salts, particularly the sodium salt, are frequently used. However, this may cause the pH of poorly buffered formulations to become more alkaline. See Methylparaben for further information
Description
Ethylparaben occurs as a white, odorless or almost odorless, crystalline powder
Stability and Storage Conditions
Aqueous ethylparaben solutions at pH 3–6 can be sterilized by autoclaving, without decomposition.(4) At pH 3–6, aqueous solutions are stable (less than 10% decomposition) for up to about 4 years at room temperature, while solutions at pH 8 or above are subject to rapid hydrolysis (10% or more after about 60 days at room temperature).(5) Ethylparaben should be stored in a well-closed container in a cool, dry place.
Incompatibilities
The antimicrobial properties of ethylparaben are considerably reduced in the presence of nonionic surfactants as a result of micellization.(6) Absorption of ethylparaben by plastics has not been reported, although it appears probable given the behavior of other parabens. Ethylparaben is coabsorbed on silica in the presence of ethoxylated phenols.(7) Yellow iron oxide, ultramarine blue, and aluminum silicate extensively absorb ethylparaben in simple aqueous systems, thus reducing preservative efficacy.(8,9) Ethylparaben is discolored in the presence of iron and is subject to hydrolysis by weak alkalis and strong acids
Safety
Ethylparaben and other parabens are widely used as antimicrobial preservatives in cosmetics, food products, and oral and topical pharmaceutical formulations.Systemically, no adverse reactions to parabens have been reported, although they have been associated with hypersensitivity reactions. Parabens, in vivo, have also been reported to exhibit estrogenic responses in fish.(10) The WHO has set an estimated total acceptable daily intake for methyl-, ethyl-, and propylparabens at up to 10 mg/kg body-weight.(11)LD50 (mouse, IP): 0.52 g/kg(12) LD50 (mouse, oral): 3.0 g/kg