Insomnia and related sleep disorders (somnipathies) affect a large segment of the population, and result in a significant negative impact on quality of life and reduced or lost productivity. The speed of sleep onset is a critical characteristic of successful pharmacotherapeutic intervention for insomnia. Zolpidem, a non-benzodiazepine benzodiazepine receptor agonist (nBzRA) is widely used to treat insomnia. Although not itself a benzodiazepine (BZD), zolpidem has high binding affinity for the benzodiazepine receptor, which acts as a positive allosteric modulator of the GABAA receptor complex. It therefore increases the neuronal transmembrane influx of Cl- ions, thereby decreasing neuronal excitability and promoting sleep. In this four-way crossover, dose-ranging, multiple-treatment study, a lingual spray formulation of zolpidem was safe and well-tolerated and yielded more rapid pharmacokinetics (mean plasma concentration) and efficacy (visual analog scale and digit symbol substitution test) compared to oral tablets.