The invention relates to cosmetic or pharmaceutical composition comprising an oil-containing biliquid foam dispersed in a salt-containing aqueous phase, in which the aqueous phase, having a pH of less than about 7, is gelled by a polymeric sulfonic acid. A particularly preferred gellant is ammonium poly(acryldimethyltauramide-co-vinylformamide). Unlike many other types of gels, these gels are stable at an acid pH in the presence of substantial amounts of electrolytes, and therefore are useful in delivering acidic active components.