Prospective, randomized, double-blind, placebo-controlled, multicentre clinical trial to assess the efficacy and tolerability of natural seawater based throat spray among adult patients with acute sore throat.

Inclusion Criteria:

• 1. Adults (male or female) aged ≥ 18 years old.
• 2. Patients with complaint of sore throat ≤ 72h.
• 3. Sore throat exclusively due to upper respiratory tract infection (tonsillitis, pharyngitis, rhinopharyngitis).
• 4. Clinical confirmation by the physician for the presence of typical signs (spontaneous pain, local inflammation) of acute pharyngitis or tonsillitis.
• 5. Pain intensity scored by patient on the 5-point descriptive pain intensity scale as slight, mild or moderate.
• 6. Willingness to provide written informed consent prior to perform of any study related procedure.
• 7. Subjects agreeing to follow the study requirements during the whole study period (including forbidden medication and food supplements).
• 8. Subjects agreeing not to modify their lifestyle habits during the whole study period (diet, physical activity).
• 9. Subject affiliated to social security.
• 10. Subject able to understand verbal and written local language and in capacity to fill-in patient diary by himself/herself.

Exclusion Criteria:

• 1. Previous history of allergy or known intolerance to one of the following formulation ingredients: seawater, vegetable glycerin, mint, lemon, acacia honey, propolis, essential oils.

• 2. Active Smokers.

• 3. Fever > 38°C at randomization.

• 4. Past or current throat phlegmon.

• 5. Past or current seasonal allergy.

• 6. Past or current asthma.

• 7. Past or current chronic rhinosinusitis.

• 8. Past or current chronic obstructive pulmonary disease (COPD).

• 9. Past or current ENT (Ear, Nose and Throat) cancer.

• 10. Acute rhinosinusitis.

• 11. Controlled or uncontrolled diabetes.

• 12. Gastroesophageal reflux disease (GERD).

• 13. Known immunodeficiency.

• 14. Any painful condition that may distract attention from sore throat pain (ex: mouth ulcers etc.) or that requires analgesic usage.

• 15. Any disease that may interfere with the study aim from investigator's opinion.

• 16. Evidence of mouth breathing or severe coughing.

• 17. Patient with severe pain intensity on 5-point descriptive pain intensity scale.

• 18. Subjects taking:

  • chronic treatment for throat or other ENT pathology,
  • current antibiotherapy or stopped less than 2 weeks before inclusion,
  • chronic treatment (>3 months) with local or systemic corticotherapy, or immunotherapy,
  • local or systemic antihistaminic.

• 19. Subjects refusing to stop at entry into the study:

  • throat spray, lozenge, pastille,
  • local throat or systemic analgesic,
  • medicated confectionary,
  • nasal wash and spray,
  • nasal corticosteroid or antihistaminic nasal spray,
  • medication to gargle,
  • honey, propolis, or any sore throat home remedies.

• 20. Known liver disease or hypersensitivity to paracetamol.

• 21. Pregnant, breastfeeding or seeking pregnancy women.

• 22. Positive result from rapid strep throat test.

• 23. Subjects already included once in this study.

• 24. Subjects participating in another clinical trial or in the exclusion period to another study.

• 25. Subjects having a member of his/her home who is currently participating to this study.