polysorbaten

Polysorbates are a family of nonionic emulsifiers derived from sorbitan esters with fatty acids and polyoxyethylene chains. They are widely used to stabilize oil-in-water mixtures, improve solubility, and act as surfactants in foods, cosmetics, and pharmaceuticals. The most common forms are polysorbate 20 (polyoxyethylene sorbitan monolaurate), polysorbate 40 (monopalmitate), polysorbate 60 (monostearate), and polysorbate 80 (monooleate).

Chemically, they consist of a sorbitan ring linked to a fatty acid via an ester bond, with multiple ethoxylate units appended to increase hydrophilicity. This combination yields a molecule with a lipophilic tail and a hydrophilic polyoxyethylene head, giving high surface activity and the ability to form micelles that solubilize lipophilic compounds. Their hydrophilic-lipophilic balance (HLB) values typically fall in the mid-to-high range, around 14–16, depending on the fatty acid moiety.

Uses: In foods, they function as emulsifiers to stabilize dressings, sauces, dairy products, and baked goods; in cosmetics and personal care, they serve as emulsifiers and solubilizers in creams, lotions, and cleansers; in pharmaceutical formulations, they act as solubilizers and droplet stabilizers, and are used in some parenteral or oral drug preparations and vaccines to improve suspension and stability.

Safety and regulation: Polysorbates are widely used and considered safe at conventional intake levels in many regulatory regimes. However, rare hypersensitivity reactions can occur, particularly with intravenous use or in susceptible individuals. Production can yield trace contaminants such as certain glycidyl esters or 3-monochloropropane diol esters; manufacturers monitor and manage this. As with all excipients, use is subject to regulatory limits and labeling in food, drug, and cosmetic products.