Study to Evaluate the Presence of a Hangover Effect in Healthy Adults After Administration of Songha® Night Tablets

Inclusion Criteria: * Healthy male or female Caucasian subjects aged 20-60 years * Normal outcome in Pittsburgh Sleep Quality Index (PSQI), below mean +2 Standard Deviation (SDs) * No manifest sleep disorder diagnosed by polysomnography * Normal pupillary function * Willing and able to give written informed consent in accordance with Good Clinical Practice (GCP) and local legislation prior to participation in the study and able to perform the study during the full time period of 36 days Exclusion Criteria: * Subjective sleep duration of less than 3 hours in the night before the test * Caffeine, nicotine or alcohol on the day (from midnight) of the test * Alcohol consumption on the evening before visits 3, 5 or 7 * Eye-drops or other drugs, taken orally or intravenously, influencing pupil size or motility * Shift work * Drug and alcohol abuse * Use of psycho-active drugs during the past 30 days * Any treatment that might interfere with the evaluation of the test drug * Any drug known to interact with benzodiazepines and related drugs, e.g. antiepileptics, antihistaminics, muscle relaxant drugs, antihypertensive drugs, drugs inhibiting cytochrome P450 * Any serious disorder that might interfere with his/her participation in this study and the evaluation of the efficacy or safety of the test drug (e.g. renal insufficiency, hepatic or metabolic dysfunction, cardiovascular disease, psychiatric disorder, myasthenia gravis, delirious state, etc.) * Known hypersensitivity to any of the ingredients of the study drugs * Pregnant or nursing women or inadequate birth control methods (this applies to female of childbearing potential only) * Participation in another trial within the past 30 days