The present invention provides for a novel oil-in-water (O/W) emulsion, with increased stability in the presence of bacterial or viral suspensions, especially those concentrated and non-purified or weakly purified. The emulsion of the present invention can act as vehicle for the delivery of a pharmaceutical composition comprising at least one immunogen and, in particular, an immunogen selected from the group comprising an inactivated pathogen, an attenuated pathogen, a subunit, a recombinant expression vector, and a plasmid or combinations thereof.