<p>A controlled release dosage forms comprising zolpidem or a salt thereof to release zolpidem to induce rapid onset of sleep, and continue to release zolpidem in a controlled manner to maintain effective plasma concentrations over an extended period of time to improve sleep maintenance. The pharmaceutical controlled-release dosage form of zolpidem or a salt thereof having a dissolution profile when measured in a type I or II dissolution apparatus according to the U.S. Pharmacopoeia in 0.01M hydrochloric acid buffer at 37° C., such that less than 40 % is released at the end of 30 minutes.</p>
