Ch. 10 Compounding Math

Percentage Strength (g/mL)

- x grams / 100 mL

- 100 / ratio strength

Ratio Strength

100 / % strength

Percentage strength to Parts per million (ppm)

move decimal right 4 spaces

PPM to percentage strength

move decimal left 4 spaces

Specific Gravity (SG)

g/mL

Formula used for Dilution & Concentration when dealing with 2 concentrations

Q1C1 = Q2C2

What technique is used to create a new product from 2 existing products of differing strengths? (3 concentrations involved)

Alligation (Tic-Tac-Toe board problem)

mOsm/L

mOsm/L = (Weight in g per L / MW) x # of particles x 1000

Isotonicity (E-value)

E = 58.5 (i) / MW (1.8)

Compounds with only 1 dissociation particle (i)

- Dextrose

- Mannitol

Compounds with 2 dissociation particles (i)

- Potassium chloride

- Sodium chloride

- Sodium acetate

- Magnesium sulfate

Compounds with 3 dissociation particles (i)

- Calcium chloride

Compounds with 4 dissociation particles (i)

- Sodium citrate

How many grams of Sodium to add to solution for isotonicity when given the E value

(1.) Calculate total amount of sodium needed to make solution isotonic

(2.) Calculate the amount of sodium equivalents already represented in the solution

(3.) Subtract step 2 from step 1 to determine how much sodium is needed

mols

mols = g/MW

mmols

mmols = mg/MW

mEq

mEq = (mg x valence) / MW

mEq = mmols x valence

Compounds with a valence of 1

- Ammonium chloride

- Potassium chloride

- Potassium gluconate

- Sodium acetate

- Sodium bicarbonate

- Sodium chloride

Compounds with a valence of 2

- Calcium Carbonate

- Calcium Chloride

- Ferrous Sulfate

- Lithium Carbonate

- Magnesium Sulfate