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Uses the sodium chloride equivalent method: the drug's tonicity contribution is subtracted from the 0.9 percent sodium chloride needed to make the volume isotonic.
E value method
Sodium chloride for isotonicity = 0.009 x volume (mL); drug contribution = drug mass x E value; sodium chloride to add = the difference
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
The mass of sodium chloride osmotically equivalent to one gram of the drug.
Hypotonic ophthalmic and parenteral solutions cause cell lysis and stinging; hypertonic ones cause pain and phlebitis.