Ondansetron Hydrochloride

Inquiry

Cat Number

API0232085

CAS Number

99614-01-4

If you have any other questions, please contact our experts.

Product Detail Description Scientific Support Advanced Innovations Customer Q&A

CAS Number

99614-01-4

EINECS

619-448-9

Storage

Store at room temperature

Synonyms

ONDANSETRON HCl; Ondemet; Zophren; ZOFRAN PRESERVATIVE FREE; Ondansetron HCl dihydrate; 2999F27MAD; SN 307; NSC-665799

Molecular Formula

C18H20ClN3O

Molecular Weight

329.8

Smiles

CC1=NC=CN1CC2CCC3=C(C2=O)C4=CC=CC=C4N3C.Cl

Appearance

White to off-white powder

Melting Point

231-232°C

Boiling Point

267.0±9.0°C at 760 mmHg

Relative Density

1.1±0.1

General Description

Ondansetron hydrochloride is a selective serotonin 5‑HT3 receptor antagonist belonging to the carbazole class of compounds. The molecule features a chiral center, and the clinically used form is the racemate, although both enantiomers exhibit similar activity. Its chemical structure is unrelated to earlier antiemetics such as metoclopramide or phenothiazines, and it lacks dopamine or histamine receptor blocking properties.

Mechanism of Action

Ondansetron competitively blocks 5‑HT3 receptors located on vagal afferent nerve terminals in the gastrointestinal tract and on chemoreceptor trigger zone neurons in the area postrema. This blockade prevents serotonin‑induced depolarization and subsequent activation of the emetic reflex. Unlike other antiemetics, ondansetron does not inhibit dopamine D2 receptors, accounting for its absence of extrapyramidal side effects.

Application

The drug is indicated for the prevention of nausea and vomiting associated with highly emetogenic chemotherapy, radiation therapy, and postoperative recovery. It is particularly effective against acute emesis induced by cisplatin and other agents that cause massive serotonin release from enterochromaffin cells. Ondansetron is also used off‑label for hyperemesis gravidarum and for gastroenteritis‑induced vomiting in children.

A meta‑analysis of eight randomized controlled trials (905 patients) evaluated ondansetron for preventing postanesthesia shivering (PAS). Compared with placebo, ondansetron significantly reduced the incidence of PAS (relative risk 0.33, 95% CI 0.19‑0.58) and lowered the risk of hypotension (RR 0.26, 95% CI 0.08‑0.79), with no difference in bradycardia. Ondansetron and pethidine showed similar efficacy (RR 0.89). The authors conclude that ondansetron effectively prevents PAS and has a favorable safety profile regarding hypotension.

Fig. 1 Flowchart of studies included in review. (He K, et al., 2016)

References

He K, et al. Efficiency and safety of ondansetron in preventing postanaesthesia shivering. Ann R Coll Surg Engl. 2016;98(6):358-366.

A patient with drug‑induced long QT syndrome was found to carry a heterozygous KCNN2 variant (p.F503L) that increased Ca²⁺ sensitivity and SK current density when expressed in HEK‑293 cells. The variant also enhanced membrane retention of the channel protein. Ondansetron, a 5‑HT₃ receptor antagonist, inhibited both wild‑type and p.F503L SK2 channels at nanomolar concentrations, as well as native SK currents in ventricular myocytes and Langendorff‑perfused hearts. Thus, ondansetron is a potent I_KAS blocker, which may be useful in arrhythmias with increased SK current but could also facilitate long QT syndrome.

Fig. 2 Ondansetron causes corrected QT (QTc) prolongation in a patient heterozygous for the p.F503L Ca2+-activated K+ channel subfamily N member 2 (KCNN2) variant. (Ko JS, et al., 2018)

References

Ko JS, et al. Ondansetron blocks wild-type and p.F503L variant small-conductance Ca2+-activated K+ channels. Am J Physiol Heart Circ Physiol. 2018;315(2):H375-H388.

Does Ondansetron Hydrochloride require protection from light during storage?

Yes, it is photosensitive. Light exposure can cause photodegradation and discoloration. Store in light-resistant containers, preferably amber glass.

What is the recommended storage temperature for Ondansetron Hydrochloride?

Store at controlled room temperature (15-25°C). Avoid excessive heat above 30°C, which can accelerate oxidative degradation of the carbazole ring.

Is Ondansetron Hydrochloride stable in solution for injection or oral use?

Aqueous solutions are stable when protected from light and stored at room temperature.

How is the impurity ondansetron N-oxide monitored during stability?

This oxidative degradation product is quantified using a stability-indicating HPLC method, ensuring it remains below USP/EP limits.