Poloxamers

Poloxamers" are low-foaming and foam-absorbing, non-ionic surfactant block polymers composed of polyethylene oxides and polypropylene oxides. Poloxamers are used for dispersion and emulsification in cosmetics (also in the chemical-technical industry and medicine). The polyethylene oxide part of the polymer is water-soluble, whereas the polypropylene oxide part is not, so that this results in the special amphiphilic properties of the compounds. Depending on the degree of ethoxylation, poloxamers are liquid, pasty, solid or powdery.

Poloxamers 101,105,108,122,123 are colorless liquids

Poloxamer 188, 237,338,407 are solid, wax-like substances with a melting point of 50°C.

Where a is the degree of polymerization of the ethylene oxide building blocks, b is the degree of polymerization of the propylene oxide building blocks.

In the case of three-digit type designations, the first two digits, when multiplied by 100, represent the approximate average molecular mass of the polypropylene oxide component, the last digit, multiplied by 10, represents the percentage by weight of polyethylene oxide.

Polaxamers are used pharmaceutically to increase the solubility of drugs. In semi-solid forms they are used as non-ionic emulsifiers, e.g. to form with suitable hydrophilic components and lipids.

In cosmetics the polaxamers with the numbers 101 to 407 (most frequently the poloxamers 1188 and 407) are used. They act as emulsifiers and surfactants.

1. Ammon HPT et al (2014) Hunnius Pharmaceutical Dictionary 11th Edition Walter de Gruyter Berlin-New York S 1431
2. v. Bruchhagen F et al (1994) Hager's Handbook of Pharmaceutical Practice. Springer Verlag, Berlin, Heidelberg, New York p 282-283