Melatonin (N-acetyl-5-methoxytryptamine, MLT), a hormone synthesized by the pineal gland and released at night, has a regulatory role on sleep in vertebrates, including humans. It has been shown to have a hypnotic action in animals and humans and it has been used as an agent for restoring circadian rhythms, disturbed by jet-lag, shift-work or aging. The physiological actions of melatonin in regulating seasonal and circadian rhythms are mediated through a family of specific, high affinity G protein-coupled membrane receptors. The beneficial effect of fast-release formulations on sleep initiation may come from the high amount of melatonin released immediately after administration, while the benefit of the sustained release systems comes from the release of melatonin in small dosages during the entire night period. This chapter covers the recent scientific work on melatonin modified release formulations.
Part of the book: Melatonin