Bis(2-ethylhexyl) sodium sulfosuccinate

Bis(2-ethylhexyl) sodium sulfosuccinate, commonly known as AOT, Docusate, or Aerosol OT (CAS 577-11-7), is an anionic surfactant with the molecular formula C20H38O7S.Na. It carries no assigned E-code. Its branched diester structure gives it an unusually low critical micelle concentration and strong interfacial activity across a broad range of systems.

In pharmaceutical manufacturing, AOT functions as a wetting agent and emulsifier by reducing interfacial tension between oil and water phases, enabling stable microemulsion formation. In industrial cleaning formulations, its sulfonated head group adsorbs onto hydrophobic surfaces, facilitating the removal of oils and greases. It is also used in water treatment as a dispersant for particulate matter.

AOT is available in technical and pharmaceutical grades, with the latter conforming to Ph.Eur. and USP/FCC monographs under the name Docusate Sodium. It is registered under REACH and supplied as a waxy solid or aqueous solution. Standard packaging includes drums and IBCs.