The Molecular formula of Ondansetron (CAS NO.99614-02-5): C₁₈H₁₉N₃O   
The Molecular Weight of Ondansetron (CAS NO.99614-02-5): 293.37
The Molecular Structure of Ondansetron (CAS NO.99614-02-5):

Density: 1.27 g/cm³
Boiling point: 546 ^°C at 760 mmHg 
Flash point: 284 ^°C   
Solubility in water: H₂O: >5 mg/mL
Index of Refraction:1.677 
Molar Refractivity: 86.75 cm³ 
Molar Volume: 230.1 cm³
Surface Tension: 48.9 dyne/cm
Enthalpy of Vaporization: 82.5 kJ/mol   
Vapour Pressure: 5.62E-12 mmHg at 25^°C 
IUPAC Name: 9-methyl-3-[(2-methylimidazol-1-yl)methyl]-2,3-dihydro-1H-carbazol-4-one hydrochloride  
Synonyms: 1,2,3,9-tetrahydro-9-methyl-3-((2-methyl-1h-imidazol-1-yl)methyl)-4h-carbazo ; Gr 38032f  ; Ondansetrone hydrochloride ; Ondansetron hcl ; Ondansetron hcl dihydrate ; Ondansetron hydrochloride dihydrate ; Gr38032

Ondansetron was developed around 1984 by scientists working at Glaxo's laboratories in London. It is in both the Imidazole and Carbazole families of heterocyclic compounds.After several attempts the company successfully filed for U.S. patent protection for the drug in 1986. U.S. Patent 4,695,578 was granted in September 1987 while U.S. Patent 4,753,789 was granted in June 1988. U.S. Patent 5,578,628, a divisional patent of U.S. Patent 4,753,789, was granted in November 26, 1996. Ondansetron was granted Food and Drug Administration (FDA) approval as Zofran in January 1991. Glaxo did pediatric research on Zofran's uses, and gained patent extension as a result. Consequently U.S. exclusivity ended December 24, 2006. The FDA subsequently approved the first generic versions in December 2006, with marketing approval granted to Teva Pharmaceuticals USA and SICOR Pharmaceuticals. It is currently marketed by GlaxoSmithKline (GSK) under the trade name Zofran; other manufacturers include Cipla Ltd. (Emeset), Gedeon Richter Ltd. (Emetron), Korea United Pharmaceuticals (Emodan), Zentiva a.s. (Ondemet) and Novell Pharmaceutical Laboratories (Ondavell). On May 29, 2006, Baxter Healthcare received tentative approval to market its own label of Ondansetron Injection, USP, 8 mg/50 mL and 32 mg/50 mL iso-osmotic sodium chloride solution, after GSK's patent expired on December 24, 2006.

It's 5 - hydroxytryptamine (5-HT3) receptor antagonist and efficient antiemetic drug, with high strength and a high degree of selectivity.It can control vomit which stimulate by receptor in the small intestine and the CTZ (chemoreceptor launch center).  

A poison by intravenous route. Human systemic effects by intravenous route: jaundice. When heated to decomposition it emits toxic vapors of NO_x.
Hazard Codes: TXi
Risk Statements
R25: Toxic if swallowed.
R36/37/38: Irritating to eyes, respiratory system and skin .
Safety Statements
S45: In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
S37/39: Wear suitable gloves and eye/face protection .
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
RIDADR: UN 2811 6.1/PG 3
WGK Germany: 3
RTECS: FE6375500