Products
Pharmacopeia-grade sodium chloride is available in pharmacies and drugstores. Available medications include, for example, nasal sprays, irrigation solutions, injection, infusion, and inhalation solutions.
Structure and properties
The officinal sodium chloride (NaCl, Mr = 58.44 g/mol) exists as a white crystalline powder, colorless crystals, or white beads. It is slightly soluble in water, practically insoluble in ethanol, and has a salty taste. Sodium chloride monographed by the pharmacopoeia has a defined quality and purity. The crystals grow in cubes due to the molecular crystal structure. Each ion is surrounded in the crystal by 6 ions with opposite charge. Sodium chloride is formed when elemental sodium reacts with chlorine gas. It is not produced synthetically, however, but is mined as rock salt in salt mines, for example, or extracted by evaporation or dissolved with water from deep rock layers with the help of boreholes. Salt is contained in sea water in unimaginably large quantities and is also the main component of sea salt (usually > 95% or more). The melting point is about 800 °C. Structure: Na+Cl– , click to enlarge.
Effects
On the one hand, sodium chloride is used for the production of medicines. The salt is used to produce a so-called physiological and isotonic solution. It contains 0.9% sodium chloride (m/V). It is prepared with 9 g NaCl added to 1 liter of water for injection. See also in the article Concentration.
| Sodium chloride | 9.0 g |
| Water for injection | ad 1000.0 ml |
However, the solution is only approximately physiological because relevant deviations exist with regard to the ion concentration, the components as well as with regard to the pH (e.g., Li et al., 2016; Reddi, 2013). In addition to the sodium concentration, especially the chloride concentration is much higher compared to blood serum. The pH is around 5.5 or even lower. This is another reason why the intake of large amounts can lead to adverse effects (see below). On the other hand, sodium chloride is also administered to substitute sodium and chloride ions. Both ions are found in a high concentration mainly in the extracellular fluid of the body. They are the two most important ions of the blood plasma. Intracellularly, however, they are found in a much lower amount, where potassium dominates. Sodium plays an important role, for example, in the conduction of impulses in the nervous system, in blood pressure and in acid-base balance.
Areas of application
Medical and pharmaceutical uses include:
- In the form of nasal sprays and solutions for the treatment of respiratory diseases, such as rhinitis, a dry nose, a stuffy nose and for hay fever.
- For wound cleansing.
- As a carrier solution for injections, infusions and inhalations.
- To store and clean contact lenses.
- In oral rehydration solution for electrolyte and fluid supplementation in acute diarrhea or vomiting. Conversely, sodium chloride is also included in some laxatives for the treatment of constipation in combination with macrogols.
- As a pharmaceutical excipient for various dosage forms.
- Sodium chloride infusion solutions can be used as fluid replacement, in dehydration, mild shock, hyponatremia and hypochloremia, among others. They are sterile, pyrogen-free and isotonic.
- Hypertonic solutions are also used for mucus clearance, for example, in cystic fibrosis.
Contraindications
Contraindications depend on the drug and the indication. For parenteral therapy, these include:
- Hypersensitivity
- Hypernatremia
- Hyperchloremia
- Hypertonic dehydration
- Hyperhydration
- Acidosis
For complete precautions, see the drug label.
Adverse effects
Locally applied solutions are usually very well tolerated. One problem is the short shelf life of unpreserved products after opening. Therefore, sodium chloride solutions are also available in single doses. Venous irritation and thrombophlebitis may occur with parenteral administration.When large amounts are administered, hyperhydration, hypernatremia, hyperchloremia, acidosis, and hypokalemia may occur.
