Inclusion Criteria:
1. Non-smoking, male and female subjects from 18 to 65 years of age.
2. BMI 18-30 kg/m2.
3. Females may be of childbearing or non-childbearing potential:
* Childbearing potential:
o Physically capable of becoming pregnant, must be willing to use acceptable effective methods of contraception
* Non-childbearing potential:
* Surgically sterile (i.e., both ovaries removed, uterus removed, or bilateral tubal ligation); and/or
* Postmenopausal (no menstrual period for at least 12 consecutive months without any other medical cause)
4. Able to tolerate venipuncture.
5. Be informed of the nature of the study and give written consent prior to any study procedure.
6. Willing and being able to remain in the clinic for the entire duration of the confinement period.
7. Have good intravenous access on both arms and hands.
8. TNSS Score =0
Exclusion Criteria:
1. Known history or presence of clinically significant neurologic, hematologic, endocrine, oncologic, pulmonary, immunologic, genitourinary, hepatic , psychiatric, or cardiovascular disease (including bradyarrhythmias) or any other condition which, in the opinion of the Investigator, would jeopardize the safety of the subject or impact the validity of the study results.
2. Known history or presence of hypersensitivity reaction to ondansetron (Zofran), any excipients of ondansetron, or any other drug substances with similar activity.
(commercial names in Israel: ODNATRON injection; ONDANSETRON - FRESENIUS injection; ONDANSETRON KALCEKS injection; ONDANSETRON INOVAMED oral tabs, ONDANSETRON BAXTER injection; Zofran oral tabs).
3. Known history or presence of any food allergy.
4. Presence of nostril or septum piercing which may interfere with nasal administration.
5. Presence of abnormal nasal anatomy (e.g., polyps, unilateral or bilateral abnormalities of the nares, nasal turbinates, or septum including deviated septum).
6. History of nasal surgery.
7. Presence of a medical condition requiring medication (prescription and/or over-the-counter) with systemic absorption other than oral contraceptives or hormone replacement therapy.
8. History of drug or alcohol addiction requiring treatment or positive drug/alcohol test at screening and check-in.
9. Any acute illness (e.g. cold, acute infection) which is considered significant by the Investigator and that has not resolved within 7 days before the first drug administration.
10. Positive test result for HIV, Hepatitis B surface antigen, or Hepatitis C antibody.
11. Positive test result for urine drugs of abuse (amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, methadone, opiates, phencyclidine, and tricyclic antidepressants) or urine cotinine.
12. Difficulty fasting or consuming standard meals.
13. Inability to communicate well with the Investigators and staff.
14. Non-cooperative or unwilling to sign consent form or unwilling to attend scheduled clinic visits and/or comply with the study protocol.
15. Use of tobacco or nicotine-containing products within 6 months prior to drug administration.
16. Females who:
* Are pregnant (hCG result consistent with pregnancy); or
* Are lactating.
17. Donation or loss of whole blood (including clinical trials):
* ≥50 mL and \<500 mL within 30 days prior to drug administration;
* ≥500 mL within 56 days prior to drug administration.
18. Participation in a clinical trial that involved administration of an investigational medicinal product within 30 days prior to drug administration, or recent participation in a clinical investigation that, in the opinion of the Investigator, would jeopardize subject safety or the integrity of the study results.
19. On a special diet within 20 days prior to drug administration (e.g., liquid, protein, raw food diet).
20. Have had a tattoo or body piercing within 30 days prior to drug administration.
21. Have clinically significant findings in vital signs measurements at screening.
22. Have clinically significant findings in a 12-lead ECG, specifically abnormal QT/QTc interval
23. Subjects with congenital long QT syndrome
24. Have clinically significant abnormal laboratory values and hemoglobin \<135 g/L for males or \<120 g/L for females at screening.
25. Subjects with electrolyte abnormalities (e.g., hypokalemia or hypomagnesemia)
26. Have significant diseases at screening.
27. Have clinically significant findings from a physical examination.
28. Use of the following drugs within 30 days prior to drug administration:
* Apomorphine (contraindication)
* Drugs having effect on cytochrome P450 (CYP450);
* Serotonergic drugs (e.g., selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors, mirtazapine, fentanyl, lithium, tramadol, and intravenous methylene blue)
* Medicinal products that lead to QT prolongation (e.g. Amiodarone, Citalopram, Clarithromycin, Diphenhydramine, Erythromycin, Fluconazole - not exhaustive)
29. Use of the following drugs within 7 days prior to drug administration:
* Nasal decongestants including nasal antihistamines;
* Nonsteroidal anti-inflammatory drugs (NSAIDs); or
* Oral or topical antihistamines.
30. Use of any medication within 1 year prior to drug administration with Thalf longer than 1 week
