Polysorbate 60

• BPPolysorbate 60
• Ph. Eur.Polysorbate 60
• USP–NFPolysorbate 60

Crillet 3; polyoxyethylene 20 sorbitan monostearate; polysorbatum 60; PEG-20 sorbitan monostearate; Tween 60; E435

Polyoxyethylene 20 sorbitan monostearate · [9005-67-8]

C64H126O26 (approximate) · ≈ 1 312

Surfactant, emulsifier

Typical concentrations: — · Dosage forms: Semi-solid

A hydrophilic nonionic surfactant used mainly as an emulsifier in oil-in-water creams, lotions and ointments, often together with a sorbitan ester such as sorbitan monostearate, and as a solubiliser and wetting agent. Typical concentrations: emulsifying agent used alone in oil-in-water emulsions 1–15%, or 1–10% when combined with lipophilic emulsifiers; solubilising agent for poorly soluble drugs in aqueous vehicles 1–10%; wetting agent for insoluble solids 0.1–3%. It is also used widely in foods, for example in bakery products, toppings and confectionery.

A mixture of partial stearic acid esters (with palmitic acid) of sorbitol and its anhydrides copolymerised with about 20 moles of ethylene oxide per mole of sorbitol. It is a yellowish-brown, gel-like semi-solid with a faint characteristic odour.

Physical form

yellowish-brown, gel-like or semi-solid mass at 25 °C that liquefies on gentle warming (above about 25 °C)

HLB

about 14.9

Saponification value

about 45–55

Solubility

soluble in water and ethanol; practically insoluble in fatty oils and liquid paraffin

Polysorbates are stable to electrolytes and weak acids and bases; strong acids and bases cause gradual saponification. The oleic-acid esters in particular are susceptible to autoxidation, forming peroxides and degrading on exposure to light, heat and metal ions. They are hygroscopic and should be stored in a well-closed, well-filled container, protected from light, in a cool, dry place; nitrogen blanketing helps limit oxidation.

Discoloration or precipitation occurs with various substances, especially phenols, tannins and tars. They reduce the antimicrobial activity of many preservatives, particularly parabens, by micellar binding, and peroxide impurities can oxidise sensitive drugs and proteins.

Prepared by esterifying sorbitol and its anhydrides (mainly sorbitan) with stearic acid and then reacting the product with about 20 moles of ethylene oxide per mole of sorbitol.

Generally regarded as non-toxic and non-irritant in oral and topical use; occasional hypersensitivity reactions have been reported. JECFA and EFSA have set a group ADI of 25 mg/kg body weight per day for polysorbates 20, 40, 60, 65 and 80.

Observe normal precautions for the quantity handled. Eye protection and gloves are recommended.

Accepted as a food additive in Europe (E435). Included in the FDA Inactive Ingredient Database (oral and topical preparations) and in non-parenteral medicines licensed in Europe.

Polysorbate 20; polysorbate 65; polysorbate 80; sorbitan monostearate.

Polysorbate 60 is semi-solid at room temperature, so it is usually warmed to about 40–50 °C and mixed before weighing or sampling. With sorbitan monostearate it forms a classic emulsifier pair whose proportions can be adjusted to match the required HLB of the oil phase.