Ondansetron (GR 38032) HCl dehydrate is an orally bioavailable, selective and competitive 5-HT3 receptor antagonist (BBB (blood-brain barrier) permeable (penetrable)). Ondansetron HCl dehydrate is used to prevent nausea and vomiting caused by cancer chemotherapy, radiation therapy, and surgery.

Physicochemical Properties

Molecular Formula	C18H24CLN3O3
Molecular Weight	365.85
Exact Mass	365.15
CAS #	103639-04-9
Related CAS #	Ondansetron;99614-02-5;Ondansetron hydrochloride;99614-01-4
PubChem CID	59774
Appearance	White to off-white solid powder
Density	1.1±0.1 g/cm3
Boiling Point	267.0±9.0 °C at 760 mmHg
Melting Point	231-232ºC
Flash Point	144.9±5.1 °C
Vapour Pressure	0.0±0.5 mmHg at 25°C
Index of Refraction	1.523
LogP	-0.37
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	2
Heavy Atom Count	25
Complexity	440
Defined Atom Stereocenter Count	0
InChi Key	VRSLTNZJOUZKLX-UHFFFAOYSA-N
InChi Code	InChI=1S/C18H19N3O.ClH.2H2O/c1-12-19-9-10-21(12)11-13-7-8-16-17(18(13)22)14-5-3-4-6-15(14)20(16)2;;;/h3-6,9-10,13H,7-8,11H2,1-2H3;1H;2*1H2
Chemical Name	9-methyl-3-[(2-methylimidazol-1-yl)methyl]-2,3-dihydro-1H-carbazol-4-one;dihydrate;hydrochloride
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: (1). Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.(2). This product is not stable in solution, please use freshly prepared working solution for optimal results.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	5-HT3 Receptor
ln Vivo	In the radiation-induced pica model, ondansetron hydrochloride dehydrate (2 mg/kg; ip; single) prevents radiation sickness when combined with dexamethasone (2 mg/kg) and CP-99,994 (15 mg/kg)[1].
Animal Protocol	Animal/Disease Models: Male mice of ICR strain (8weeks old; 30-36 g; radiation-induced pica model (kaolin ingestion behavior “pica” may be analogous to nausea and vomiting in mice))[1]. Doses: 2 mg/kg Route of Administration: intraperitoneal (ip) injection; single. Experimental Results: Slightly decreased the radiation-induced kaolin consumption by dexamethasone to 48% of the control. demonstrated good activity of blocking radiation sickness by combining with Dexamethasone (2 mg/kg) and CP-99,994 (15 mg /kg).
Toxicity/Toxicokinetics	Effects During Pregnancy and Lactation ◉ Summary of Use during Lactation Ondansetron is frequently used for nausea during and after cesarean section, usually in doses of 4 to 8 mg intravenously. Use during and after cesarean section appears to not affect the onset of breastfeeding. No adverse infant effects have been reported in this setting or among women who received ondansetron postpartum in a pharmacokinetic study. Use of ondansetron in nursing mothers beyond the immediate postpartum setting has not been studied well, but the drug is labeled for use in infants as young as 1 month of age. A computer model demonstrated that the amounts in milk are much less than this dose. No special precautions are required. ◉ Effects in Breastfed Infants In a pharmacokinetic study of 78 women who received ondansetron intravenously postpartum, no adverse effects were reported in their breastfed infants. ◉ Effects on Lactation and Breastmilk A randomized, double-blind study compared placebo to intravenous ondansetron 4 mg given after cesarean section as prophylaxis for postoperative nausea and vomiting. There was no difference in the time of the first breastfeeding between the two groups. In a retrospective study of women undergoing cesarean section deliveries, 3 regimens were compared: dexmedetomidine before anesthesia and during delivery (n = 115), normal saline before anesthesia and during delivery and dexmedetomidine after delivery (n = 109), and normal saline before anesthesia and during delivery (n = 168). All women received ondansetron 4 mg as needed and before removal of sutures. The average total amount of ondansetron consumed in the women ranged from 6 mg to 9 mg in the various groups. The time to first production of milk was similar in all groups (25 to 28 minutes).
References	[1]. Ondansetron, dexamethasone and an NK1 antagonist block radiation sickness in mice. Pharmacol Biochem Behav. 2005 Sep;82(1):24-9. [2]. Ondansetron. A review of its pharmacology and preliminary clinical findings in novel applications. Drugs. 1996 Nov;52(5):773-94.
Additional Infomation	Ondansetron hydrochloride is a member of carbazoles. Ondansetron Hydrochloride is the hydrochloride salt of the racemic form of ondansetron, a carbazole derivative and a selective, competitive serotonin 5-hydroxytryptamine type 3 (5-HT3) receptor antagonist with antiemetic activity. Although its mechanism of action has not been fully characterized, ondansetron appears to competitively block the action of serotonin at 5HT3 receptors peripherally in the gastrointestinal tract as well as centrally in the area postrema of the CNS, where the chemoreceptor trigger zone (CTZ) for vomiting is located, resulting in the suppression of chemotherapy- and radiotherapy-induced nausea and vomiting. A competitive serotonin type 3 receptor antagonist. It is effective in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs, including cisplatin, and has reported anxiolytic and neuroleptic properties. See also: Ondansetron Hydrochloride (annotation moved to).

Solubility Data

Solubility (In Vitro)

DMSO: 100 mg/mL (273.34 mM) H2O: 16.67 mg/mL (45.57 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.83 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (6.83 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.7334 mL	13.6668 mL	27.3336 mL
	5 mM	0.5467 mL	2.7334 mL	5.4667 mL
	10 mM	0.2733 mL	1.3667 mL	2.7334 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.