What is the difference between isotonic and hypertonic solution?

Wellness · Natural ingredients · Disorder

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When dealing with a nasal congestion problem, as in the case of a cold, reference is often made to isotonic and hypertonic solutions.

In these situations, the normal function of cilia, which are small hairs present on the mucous membranes of the upper respiratory tract, is compromised. Cilia play a key role in promoting mucous flow and in the removal of crusts, allergens, and pathogens. When the movement of cilia is slowed down, the natural cleaning process is compromised, leading to the accumulation of mucus that can become a reservoir for viruses and bacteria.

In these circumstances, nasal irrigation with isotonic or hypertonic solutions can be highly advantageous, as it is beneficial for:

  • Improving the mucociliary clearance system.
  • Hydrating the nasal mucosa.
  • Reducing the local concentration of pro-inflammatory mediators, which are substances that activate and regulate inflammatory reactions.

Isotonic and Hypertonic Solution

The world of saline solutions for nasal irrigation is divided into 2 categories: isotonic solutions and hypertonic solutions. Isotonic and hypertonic solutions are entirely natural remedies that allow for daily nasal washes and represent the most natural solution against a stuffy nose. They should not be considered as medications, as they do not contain a synthetic chemical active ingredient, but rather a simple basic composition with water and salt; sometimes, they may include added moisturizing and soothing components such as, for example, hyaluronic acid.

What is the main difference between isotonic and hypertonic solutions?

  • Isotonic solution: An isotonic solution has a sodium chloride (NaCl) concentration of 0.9%, or about 9g per liter. At this concentration, the solution is in equilibrium with the bloodstream and does not affect the movement of fluids to and from the endothelial cells of the veins.
  • Hypertonic solution: It is a solution with higher tonicity and salt concentration than that of the blood (typically 2.2-2.4%).

When is it better to use one rather than the other? Let's find out together!

Isotonic solution is gentler on nasal mucous membranes. It has a moisturizing and decongestant action, valuable for eliminating excess mucus and clearing the nose. It is also suitable for complete daily hygiene of the nasal cavities, maintaining the health of the respiratory tract mucosa. It can be used for nasal washes even by children and for prolonged use.

Hypertonic solution induces an osmotic process in which excess water in the nasal mucosa is drawn, making the mucus more fluid. The use of this type of solution can be helpful in promoting the thinning of mucus in the mucosa and its elimination. It is recommended in cases of severe nasal congestion, rhinitis, sinusitis, and for a limited period (usually 7/10 days).

Isotonic solution
Hypertonic solution
Mechanism of action
It ensures a mechanical cleaning of the nasal passages without osmotic gradient
Exploiting the osmotic gradient, it favors a water recall and a reduction of the submucosal edema greater than the isotonic solution
Mucociliary clearance
It enhances mucociliary clearance through mechanical cleansing action
In addition to moisturizing the mucosa, it increases Ca2+ levels and intracellular inflammatory mediators, ensuring a greater increase in mucociliary clearance
compared to the isotonic solution
Prevention and daily hygiene of the nasal passages
Rhinitis, rhinosinusitis and acute and chronic nasopharyngitis
Time limit
No time limit
Limited time

Otosan Nasal Wash Kit for Nasal Irrigation

Otosan Nasal Wash is suitable for daily hygiene of the nasal mucosa and as an aid in the treatment of allergies, colds, rhinitis, sinusitis, and various conditions affecting the nasal mucosa that may compromise respiratory well-being.

Thanks to its exclusive formulation, Otosan Nasal Wash combines the benefits of Saline Solution with those of Sodium Bicarbonate and 9 milligrams of Hyaluronic Acid, maximizing the advantages of nasal washing. The saline solution passes through the nasal passages, thoroughly washing them and contributing to the breakdown of bacterial biofilm; Sodium Bicarbonate balances the pH and stimulates mucociliary transport, while Hyaluronic Acid promotes mucosal repair.

Recent clinical studies carried out on adults and children, using a salt solution enriched with 9 milligrams of hyaluronic acid, have shown that Otosan Nasal Wash speeds up healing and is significantly more effective than just saline washes.

With Otosan Nasal Wash, you can choose the tonicity level of nasal washes according to your needs.

Depending on whether you want to achieve a more or less hypertonic solution, the wash can be performed using a pre-dosed sachet (1.1%), which is a mildly hypertonic solution, or two sachets (2.2%) to obtain a stronger hypertonic solution. On both occasions, the pre-dosed sachets should be fully dissolved in the bottle filled with water up to the marked level.

The mildly hypertonic saline solution (1 sachet of Otosan Nasal Wash equal to 1.1% salt) has the same concentration of sodium chloride as normally found in the cells and physiological fluids of our body. The isotonic solution is useful in cases of allergic rhinitis, sinusitis, colds, and nocturnal snoring.

Washing with isotonic solution exerts a mechanical action, mechanically removing mucus, crusts, foreign substances, and various air contaminants such as viral and bacterial pathogens, pollutants, pollen, etc. It also moisturizes the nasal mucosa with positive effects in preventing recurrences of many airway pathologies. Washes with isotonic or slightly hypertonic solutions can be performed every day without specific contraindications.

The hypertonic saline solution (2 sachets of Otosan Nasal Wash equal to 2.2% salt) has a cleaning mechanical action on the nasal cavities entirely similar to that of physiological saline solution. In addition to the physiological wash, it adds the benefits of osmotic action: being more concentrated in salts, when it comes into contact with the nasal mucosa, it draws excess water from the cells of the nasal mucosa, diluting the mucus and making it more fluid.

Hypertonic solution is indicated in cases of severe nasal congestion, chronic sinusitis, and post-operatively (for a maximum of 10 days). Its use is not recommended in the presence of lesions and abrasions of the nasal mucosa or a predisposition to nasal bleeding. On particularly delicate mucous membranes, a slight burning sensation may be felt. Hypertonic solution cannot be used for more than 10 days.

For a correct and safe use of Otosan Nasal Wash Kit, always remember to read the instructions on the product. If the problem persists, consult your doctor.

Product Line

Nasal Wash Otosan

Nasal wash ideal for daily nose hygiene and as a treatment for allergies, colds and sinusitis.

Otosan® Nasal Wash is useful in case of:

  • nasal congestion;
  • cold or allergic rhinitis;
  • acute and chronic sinusitis;
  • hypertrophic rhinitis during pregnancy;
  • snoring at night;
  • staying in dry or polluted environments;
  • exposure to fumes and irritants;
  • surgery (before and after);
  • daily cleansing of the nasal cavities.

Since it is constantly in contact with a large number of allergens, impurities and polluting dusts, keeping the nose clean and clear is the first step to prevent alterations of the mucous membrane of the nose (blocked nose, itching and dryness) and to allow correct airflow in the respiratory tract.

Autorizzazione Ministero della Salute del 29.05.12

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It is a CE medical device.
Read the instructions for use carefully.

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