- Product Name:
- Nipazin A
- Para-hydroxybenzoic acid ethyl ester
- p-Hydroxybenzoic ethyl ester
- Product Categories:
- Aromatic Esters
- Pharmaceutical Raw Materials
- Mol File:
Ethylparaben Chemical Properties
- Melting point:
- 114-117 °C (lit.)
- Boiling point:
- 297-298 °C (lit.)
- 1.1708 (rough estimate)
- vapor pressure
- 0.00012 hPa (25 °C)
- refractive index
- 1.5286 (estimate)
- Flash point:
- storage temp.
- Very slightly soluble in water, freely soluble in ethanol (96 per cent) and in methanol.
- Crystalline Powder
- 4.5-5.5 (H2O, 20°C) (saturated solution)
- Water Solubility
- Slightly soluble in water.
- Stable. Combustible. Incompatible with strong oxidizing agents, strong bases.
- CAS DataBase Reference
- 120-47-8(CAS DataBase Reference)
- NIST Chemistry Reference
- EPA Substance Registry System
- Ethylparaben (120-47-8)
Ethylparaben Usage And Synthesis
white crystalline powder
Ethylparaben occurs as a white, odorless or almost odorless, crystalline powder.
Preservative for pharmaceuticals.
Ethylparaben is prepared by the esterification of p-hydroxybenzoic acid with ethanol (95%).
The Journal of Organic Chemistry, 39, p. 3343, 1974 DOI: 10.1021/jo00937a007
Ethylparaben is widely used as an antimicrobial preservative in
cosmetics,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.
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.
This substance is one of the parabens family. Parabens are esters formed by p-hydroxybenzoic acid and an alcohol. They are largely used as biocides in cosmetics and toiletries, medicaments, or food. They have synergistic power with other biocides. Parabens can induce allergic contact dermatitis, mainly in chronic dermatitis and wounded skin.
Ethylparaben and other parabens are widely used as antimicrobial
preservatives in cosmetics, food products, and oral and topical
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.
LD50 (mouse, IP): 0.52 g/kg
LD50 (mouse, oral): 3.0 g/kg
Aqueous ethylparaben solutions at pH 3–6 can be sterilized by
autoclaving, without decomposition. 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
Ethylparaben should be stored in a well-closed container in a cool, dry place.
The antimicrobial properties of ethylparaben are considerably
reduced in the presence of nonionic surfactants as a result of
micellization. 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. Yellow iron oxide, ultramarine blue, and
aluminum silicate extensively absorb ethylparaben in simple
aqueous systems, thus reducing preservative efficacy.
Ethylparaben is discolored in the presence of iron and is subject to hydrolysis by weak alkalis and strong acids.
Accepted as a food additive in Europe. Included in the FDA Inactive Ingredients Database (oral, otic, and topical preparations). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
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