There is provided a formulation suitable for sublingual administration comprising zolpidem, which formulation provides inter alia a measurable plasma concentration of drug within 10 minutes of administration. The formulation is capable of providing sleep on demand, and comprises particles of drug, for example zolpidem or a pharmaceutically-acceptable salt thereof and a mucoadhesion promoting agent, such as sodium carboxymethylcellulose, which particles of drug and mucoadhesive are presented upon the surface of larger carrier particles.
