Lunesta or Eszopiclone is a hypnotice nonbenzodiazepine agent which has a molecular weight of 388.81 and is a light white yellow and is crystalline in nature. It dissolves in water and in ethanol it is slightly soluble. Also, it dissolves in phosphate buffer. When it has to be orally administered, it comes in the form of film coated medicines. It contains ingredients like colloidal silicon dioxide, hypromellose, magnesium microcrystalline cellulose, triacein, titanium dioxide, polyethylene glycol and calcium phosphate.