PHARMACEUTICAL COMPOSITIONS
Polysaccharides comprising at least 5 sialic acid residues per molecule and used to increase the circulation time, decrease the immunogenicity and/or increase the stability in vivo of pharmaceutically active compounds. The pharmaceutically active compound may be a foreign protein which is covalently bound to the polysaccharide. Alternatively the active compound may be associated with a drug delivery system (DDS), for instance a macro-molecular DDS or a particulate DDS, such as liposomes. The polysaccharide is usually a bacterial polysaccharide, e.g. a glycolipid or a derivative thereof, for instance polysaccharide B or E. Coli K1, N. meningitidis, Moraxella liquifaciens or Pasteurella aeroginosis, or K92 of E. Coli K92 strain.