Abstract: A formulation for administration of a medicinal substance, comprises a sandwich biscuit having two or more biscuit layers that support filler layer(s), in which the filler layer comprises a dosage unit form, or a multiple or sub-multiple thereof, of a medicament that is unpalatable in having, for example, a gritty texture or a chalky texture or other unpleasant mouth feel. The biscuit layer of the sandwich biscuit may be a plain, non-medicated, biscuit layer or may itself contain a medicament. In the latter instance, it is possible to select a different medicament for the filler layer from that in the biscuit layer, whereby the two medicaments have a co-operating or synergistic effect. The formulations also allow large dosages of drugs to be administered effectively in a palatable form and are suitable for the long-term administration of drugs.