Isotonic Solution
A solution having the same osmotic pressure as another, so that no net osmotic flow occurs between them.
Formula / equation
π₁ = π₂
Unit
atm
In depth
Isotonicity with body fluids is essential in medicine, since cells placed in a non-isotonic environment either swell and burst or shrivel. Intravenous fluids and eye drops are therefore formulated to match the roughly 0.30 osmol/L of blood plasma.
Examples in the real world
0.9% saline and 5% glucose solution are both isotonic with blood and safe for intravenous infusion.