The present invention provides structured surfactant systems comprising water and from 0 to saturation of sugar, together with sufficient surfactant to form a structure capable of suspending solids, wherein the surfactant comprises a mixture of: (i) a major portion of at least one sugar ester and/or a triterpenoid glycoside (saponin) having an HLB greater than 10 and (ii) a minor portion of at least one fatty acid and/or lecithin. The invention further provides pharmaceutical compositions comprising a structured surfactant system of the invention and a pharmaceutical or veterinary active ingredient.
