An oral drug delivery system which comprises a biliquid foam comprising: from 1 to 20% by weight of a continuous hydrophilic phase, from 70 to 98% by weight of a pharmaceutically acceptable oil which forms a discontinuous phase, the said pharmaceutically acceptable oil having dissolved or dispersed therein a poorly water-soluble drug in an amount of from 0.1 to 20% by weight and the biliquid foam including therein from 0.5 to 10% by weight of a surfactant to enable the formation of a stable biliquid foam, all percentages being based upon the total weight of the formulation.
