The primary objective of the study is to evaluate the safety and tolerability of Neu-P11, following the administration of multiple ascending oral doses (2, 5, 20, 50 mg or matching placebo) given nightly over 2 periods of 5 days to male and female subjects with primary insomnia. In addition, the study is aimed to determine the pharmacokinetic profile of Neu-P11 after 1 and 5 days of administration and to evaluate the hypnotic effects of Neu-P11 as well as the effects on mood and memory. The study hypothesis is that Neu-P11 is safe, tolerated and have significant sleep promoting effects.