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. In one embodiment, the present invention provides for an injectable oil-in-water (O / W)
emulsion comprising: (1) an
aqueous solution containing an
immunogen, said immunogen selected from the group comprising an inactivated
Mycoplasma hyopneumoniae bacterium, an inactivated
porcine circovirus type 2 (PCV-2)
virus or combinations thereof; (2) a
mineral oil; (3) a non-ionic lipophilic surfactant; and (4) a non-ionic hydrophilic surfactant having a low HLB value which comprises ethoxylated
fatty acid diesters of
sorbitan (generally having HLB value between 11 and 13). In another preferred embodiment, the present invention provides for an injectable oil-in-water (O / W) emulsion comprising: (1) an
aqueous solution containing an immunogen; (2) a non-ionic hydrophilic surfactant having a high hydrophilic-lipophilic balance (HLB) value greater than 13 and less than 40, in particular HLB≧13.5, and preferably HLB≧14; (3) a
mineral oil; (4) a non-ionic lipophilic surfactant; and (5) a non-ionic hydrophilic surfactant having a low HLB value (HLB value of about 9 to about 13).