Isotonicity (sodium chloride equivalent method)
Sodium chloride (or another tonicity agent) needed to make a solution isotonic, using E values you enter.
Inputs
1 of 4mL
In the final volume
Optional
Optional
1 for sodium chloride; enter another agent's E to use it instead
When to use
- Adjusting tonicity of ophthalmic, nasal, or parenteral solutions.
Pearls and pitfalls
- E is the grams of sodium chloride osmotically equal to 1 g of the drug. Enter the E value from your reference for each ingredient.
- A negative result means the solution is already hypertonic before adding any sodium chloride.
Why use
Shows how much tonicity each ingredient contributes and how much agent to add.
NaCl needed (g) = 0.009 × volume (mL) − Σ (drug g × E); other agent (g) = NaCl needed ÷ E of that agent