Unguentum emulsificans aquosum (dab)

Unguentum emulsificans aquosum (see below creams, hydrophilic R279), a hydrophilic ointment containing water, by definition belongs to the hydrophilic O/W creams (see below creams, hydrophilic). The designation of the German Pharmacopoeia ( DAB) as ointment is therefore actually not applicable. In this vehicle system the lipophilic phase represents the inner dispersed incoherent phase and the hydrophilic phase the outer coherent phase. The lipid content of UEA is 21% the water content is 70%. UEA contains the complex emulsifier "Emulsifying cetylstearyl alcohol Ph Eur". This gives the cream an anionic character (incompatibilities with cationic additives); due to the composition of UEA the outer hydrophilic phase can be extended e.g. with water (maximum about 1:4). This leads to lotion-like preparations.

Instead of the trick of the aqueous dilution of the O/W cream, one can also use the Hydrophilic Base Emulsion NRF S.25.) standardized in the NRF. This emulsion contains only 5% fat and 85% water.

1. Wolf G (2011) Changes to a vehicle system. Dermatologist 62: 410-411