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[article]
Titre : |
Buffering properties of trimethylglycine (betaine) in cosmetics |
Type de document : |
texte imprimé |
Auteurs : |
L. Rigano, Auteur ; V. D'Amato, Auteur |
Année de publication : |
2003 |
Article en page(s) : |
p. 55-58 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
Bétaïnes Ingrédients cosmétiques
|
Index. décimale : |
668.5 Parfums et cosmétiques |
Résumé : |
trimethylglycine, also called betaine, (C5H11NO2) is very vommon amphoteric molecule, which can be found in nature in the shell of crustaceans and in many plants. It is industrially produced by extraction from molasses in the suger industry. Trimethylglycine is a stable zwitterion (dipolar ion) with, tending to form hydrogen bonds. It strongly interacts with water and many polar molecules, imparting usual properties to solutions. Moreover, it is quite asymmetrical, as it is made of an hydrophilic part (the positive and negative ions) and of a lipophilic one (the three methyl and the methylene group). Its chemical structure, made up of the inner salt of a weak acid and a strong alkali, provides neutralising and buffering properties toward strong acids as well as making soluble some acid compounds which are hard to dissolve. In aqueous solutions, betaine forms very strong hydrogen bonds (8-9 kcal/mole) and changes the water activity. The carboxylic group attracts the hydrogen atoms of the surrounding water molecules, while the quaternised nitrogen attracts oxygen in the water structure. Therefore, betaine is surrounded by high number of co-ordinated water molecules. However, they are quickly exchanged with the surrounding bulk water molecules. Therefore, betaine is a carrier of water. This mechanism allows the water to be totally available for the survival of living cells in extreme conditions, from which the name of "stress molecules". When used in cosmetics, trimethylglycine was found to have interesting characteristics : a good dissolving power, the capacity of stabilising foam and enhancing the skinfeel. In efficacy tests, it improved the cutaneous elasticity and provided moisture to the skin. Morever, it reduces skin irritation induced by surfactants. |
Note de contenu : |
- Other compounds
- Further developements on aluminium chlorohydrate solutions |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=28146 |
in SOFW JOURNAL > Vol. 129, N° 7 (07/2003) . - p. 55-58
[article]
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