Name: Linoleic Acid
CAS No: (Z,Z)-9,12-Octadecadienoic acid [60-33-3]
None adopted.
Emersol 310; Emersol 315; leinoleic acid; 9-cis,12-cis-linoleic acid; 9,12-linoleic acid; linolic acid; cis,cis-9,12-octadecadienoic acid; Pamolyn; Polylin No. 515; telfairic acid.
(Z,Z)-9,12-Octadecadienoic acid [60-33-3]
C18H32O2 280.45
Linoleic acid is used in topical transdermal formulations,(1–15) in oral formulations as an absorption enhancer,(9,10) and in topical cosmetic formulations as an emulsifying agent,(15) and in aqueous microemulsions.(16) It is also used in parenteral emulsions for total parenteral nutrition and in nonprescription oral dietary supplements.
Linoleic acid occurs as a colorless to light-yellow-colored oil.
See Section 18.
Boiling point 2308C at 16 mmHg Density 0.9007 g/cm3 Iodine value 181.1 Melting point –58C Refractive index nD 20 = 1.4699 Solubility Freely soluble in ether; soluble in ethanol (95%); miscible with dimethylformamide, fat solvents, and oils.
Linoleic acid is sensitive to air, light, moisture, and heat. It should be stored in a tightly sealed container under an inert atmosphere and refrigerated.
Linoleic acid is incompatible with bases, strong oxidizing agents, and reducing agents.
Linoleic acid is obtained by extraction from various vegetable oils such as safflower oil.
Linoleic acid is widely used in cosmetics and topical pharmaceutical formulations, and is generally regarded as a nontoxic material. On exposure to the eyes, skin, and mucous membranes, linoleic acid can cause mild irritation.
Observe normal precautions appropriate to the circumstances and quantity of material handled. Gloves and eye protection are recommended.
GRAS listed. Approved for use in foods in Europe and the USA
Ethyl linoleate; methyl linoleate. Ethyl linoleate Empirical formula C20H36O2 CAS number [544-35-4] Synonyms Linoleic acid ethyl ester; 9,12-octadecadienoic acid ethyl ester; vitamin F. Comments Ethyl linoleate is used in pharmaceutical formulations as an emollient and humactent. It is also used as a solvent for fats. The EINECS number for ethyl linoleate is 208-868-4. Methyl linoleate Empirical formula C19H34O2 CAS number [112-63-0] Synonyms 9,12-Octadecadienoic acid, methyl ester. Comments Methyl linoleate is used in cosmetics as an emollient. The EINECS number for methyl linoleate is 203-993-0
Studies have shown that conjugated linoleic acid increases paracellular permeability across human intestinal-like Caco-2 cell monolayers, and consequently may also, as a dietary supplement, increase calcium absorption in vivo. (17) Linoleic acid has been shown to reduce skin irritation following acute perturbations, exhibiting clinical effects that are comparable to glucocorticoids.(18) A pre-emulsified linoleic acid system has been used to investigate the protective actions of phenolic compounds against lipid peroxidation.(19) Linoleic acid was found to have a toxic effect on melanoma cells, causing loss of membrane integrity and/or DNA fragmentation.(20) Linoleic acid was also found to promote apoptosis and necrosis of human lymphocytes(21) and Jurkat cell death(22) (Jurkat cells are a T-lymphocyte cell line) by mitochondrial depolarization. As a result, it has been suggested that oleic acid may offer a less immunologically problematic alternative to linoleic acid in parenteral nutritional emulsions. However, linoleic acid also reduced genetic damage to normal human lymphocytes caused by benzo(a)- pyrene.(23) Evidence suggests that linoleate-enriched oil such as sunflower seed oil may enhance skin barrier function,(24) and it has also been shown that linoleic acid is capable of improving epithelial integrity following mucosal injury.(25) Linoleic acid has been shown to act as a comedolytic agent in acne-prone patients(26) and may have a possible use as a cosmeceutical in acne juvenilis therapy.(27) Linoleic acid was found to selectively modulate vascular cytotoxicity caused by TNF-alpha and persistent organic pollutants such as polychlorinated biphenyls.(28) Although not included in any pharmacopeias, a specification for linoleic acid is contained in the Food Chemicals Codex (FCC); see Table I. The EINECS number for linoleic acid is 200-470-9.