Description Solwin 0.9% is a sterile, nonpyrogenic solution of sodium chloride in water for injection. It contains 900 mg of sodium chloride per 100 mL, making it an isotonic solution, meaning its salt concentration is similar to that of human blood. It is intended for intravenous administration.

Indication This solution is used for a variety of purposes, including:

• Parenteral replenishment of fluid and electrolytes, especially in cases of dehydration, hypovolemia, or mild sodium depletion.
• Serving as a vehicle or diluent for the intravenous administration of other compatible drugs.
• Acting as a priming solution for medical procedures like hemodialysis.
• Initiating and terminating blood transfusions.

Mechanism of Action When administered, the solution provides a source of water and electrolytes, specifically sodium (Na+) and chloride (Cl−) ions.

• Sodium (Na+): This is the principal cation of the extracellular fluid and plays a major role in controlling water distribution, fluid balance, and osmotic pressure in the body.
• Chloride (Cl−): This is the major extracellular anion and works with sodium to maintain the acid-base balance.

The isotonic nature of the solution allows it to expand the intravascular volume without causing significant shifts of fluid between the intracellular and extracellular spaces. The distribution and excretion of both ions are primarily managed by the kidneys, which maintain a balance between intake and output.