Poloxamer 188

Details

A synthetic big copolymer molecule that is used as a solubilizer, mild cleansing agent and foam booster or stabilizer. 

If you want to understand poloxamers more, we have a shiny description at Poloxamer 184 and Poloxamer 407. This particular poloxamer, the 188 is quite similar to the 184 version, but it is more water-soluble (80% water-soluble parts) so it can act more as a solubilizer helping to dissolve oil-loving things in water-based formulas. Similar to 184, this one also works as a mild cleansing agent, but while 184 is claimed to be more effective at cleansing, the 188 is better at foaming.