1. Preparation of Solutions (cont.)
Universal solvent – water
Diluent
Substance used to dilute
Solvent
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Water is the most common solvent.
Normal Saline is an example of a solution.
0.9 g of NaCl in each 100 mL
NaCl is the solute.
Water is the solvent or diluent.

2. Preparation of Solutions (cont.)
Percent concentration
Expression of the concentration
Amount of solute per 100 mL solution
Milliliters/100 mL for liquid solutes
Grams/100 mL if solute is a solid or semisolid
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Most solutions are prepared by the manufacturer. Examples of solutions made by the manufacturer are:
injections;
eye drops;
cough syrups.
It may be necessary to prepare solutions from powders or dilute a more concentrated solution than the concentration ordered.

3. Preparation of Solutions (cont.)
Example
What is the amount of hydrocortisone powder in 300 mL of 2% hydrocortisone lotion?
2% hydrocortisone lotion contains 2 g of hydrocortisone powder per each 100 mL.
Therefore, 300 mL will contain (2 g x 3) 6 g hydrocortisone powder.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

4. Preparation of Solutions (cont.)
Example
What is the amount of isopropyl alcohol in 100 mL of a 70% isopropyl alcohol solution? Percent strength = 70 so a 70% isopropyl alcohol solution has 70 mL isopropyl alcohol per each 100 mL solution. 100 mL has 70 mL isopropyl alcohol with enough water added to make a total of 100 mL.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

5. Preparation of Solutions (cont.)
Rule 16-2 For solid or semisolid mixtures prepared with a dry medication, percent strength represents the number of grams of medication in 100 g of the mixture.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

6. Preparation of Solutions (cont.)
Rule 16-2 (cont.) For solid or semisolid mixtures prepared with a liquid medication, percent strength represents the number of milliliters of medication in 100 g of the mixture.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

7. Preparation of Solutions (cont.)
Determine the amount of hydrocortisone in 2% hydrocortisone ointment. Each 100 mL of ointment contains 2 g of hydrocortisone. 2 g hydrocortisone would be mixed with 98 g petroleum jelly.
Example
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

8. Preparation of Solutions (cont.)
When preparing percent solutions and solids
measure the solute;
add a sufficient quantity of solvent to bring the total to the desired volume;
know qsad – a sufficient quantity to adjust the dimensions to….
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
qsad – Latin phrase
To make a liquid solution, the diluents are added up to the desired volume.

9. Preparation of Solutions (cont.)
A “recipe” for preparing 100 mL of 2% lidocaine solution:
Example
2% Lidocaine Solution
Lidocaine 2g
Water qsad 100 mL
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
You must account for the volume of the lidocaine being added to the solution, so you add a sufficient quantity of water to equal 100 mL.

10. Preparation of Solutions (cont.)
A “recipe” for preparing 100 g of 10% zinc oxide ointment from zinc oxide powder and petroleum jelly
Example
10% Zinc Oxide Ointment
Zinc Oxide g
Petroleum jelly g
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
When adding a solid to another solid (ointment base), subtract the number of grams of the solute from the total number of grams to determine how much base product you need.
You do not use qsad when preparing solid mixtures.

11. Preparation of Solutions (cont.)
Procedure Checklist 6-1: Calculating by the Proportion Method
Write a conversion factor with the
units needed in the numerator or before the colon;
units converting from in the denominator or after the colon.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

12. Preparation of Solutions (cont.)
Procedure Checklist 6-1: (cont.)
Write a factor
with the unknown, “X,” in the numerator or before the colon .
with the number to convert in the denominator or after the colon.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings
X/B or X:B

13. Using Conversion Factors: Proportion Method (cont.)
Procedure Checklist 6-1: (cont.)
Set the two factors up as a proportion.
Cancel units.
Cross-multiply or multiply the means and extremes and solve for the unknown value.
X/B = C/D or X:B = C:D
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings
Remember rules for cancelling units.
Cross-multiply for fractions
Multiply means and extremes for ratios

14. Preparation of Solutions (cont.)
Calculate the amount of NaCl needed for for 250 mL of 0.9% sodium chloride. 0.9 g NaCl in 100 mL solution Step A Convert No conversion is needed.
Example
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

15. Preparation of Solutions (cont.)
Example
0.9 g NaCl in 100 mL solution
Step B Calculate using the proportion method.
0.9 g /100 mL = X/250 mL
0.9 g x 250 = 100 x X
225 g/100 = 100X/100
2.25 g NaCl = X
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings
First ratio is our known – 0.9 g / 100 mL solution
Second ratio – X (the unknown)/250 mL
Cancel units (mL).
Cross multiply and solve the equation.

16. Preparation of Solutions (cont.)
Step C Think!...Is It Reasonable?
Since there is 0.9 g of NaCl in 100 mL, there should be more than 2 times that amount in 250 mL, so 2.25 g is a reasonable answer.
Example
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

17. Preparation of Solutions (cont.)
Procedure Checklist 6-2: Calculating by Dimensional Analysis
Write the unknown “X” on one side of the equation.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings
X =

18. Preparation of Solutions (cont.)
Procedure Checklist 6-2 (cont.)
On the other side of the equation, write a conversion factor with the units of measure for the answer on top and the units you are converting from on the bottom.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

19. Preparation of Solutions (cont.)
Procedure Checklist 6-2 (cont.)
Multiply the numerator of the conversion factor by the number that is being converted divided by 1.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

20. Preparation of Solutions (cont.)
Procedure Checklist 6-2 (cont.)
Cancel units.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

21. Preparation of Solutions (cont.)
Procedure Checklist 6-2:
Solve the equation.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

22. Preparation of Solutions (cont.)
Step C Think! … Is It Reasonable? Regardless of the method used, we find that 2.25 g of NaCl is needed to prepare 250 mL of a 0.9% solution.
Example
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

23. Preparation of Solutions (cont.)
Write the recipe for 250 mL of 0.9% sodium chloride solution.
Example
0.9% Sodium Chloride Solution
NaCl g
Water qsad 250 mL
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

24. Practice
Write a recipe for preparing 50 g if a 10% zinc oxide ointment using zinc oxide powder and petrolatum jelly.
ANSWER:
10% Zinc Oxide Ointment
Zinc oxide powder 5g
Petroleum jelly g
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings
Step A Convert – not necessary
Step B Calculate –
X = 10 g/100 g x 50g/1
X = 500g/100
X = 5 g
Step C – 50 g is half of 100 g, so 5 g zinc oxide is reasonable.

25. Preparing a Dilution from a Concentrate
When preparing a solution from two solutions of different concentration, know
Solvent – less concentrated solution
Solute – more concentrated solution
To calculate, use
Formula method
Alligation
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

26. Preparing a Dilution from a Concentrate (cont.)
Procedure Checklist 16-1
Formula Method
Identify information needed:
V = volume of solution needed
C = concentration of solution needed
St = amount of solute
Sv = amount of solvent
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

27. Preparing a Dilution from a Concentrate (cont.)
Procedure Checklist (cont.)
Insert values into formula:
C x V = St
Determine the amount of solvent by subtracting the solute from the total volume:
V – St = Sv
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

28. Preparing a Dilution from a Concentrate (cont.)
Ordered: 1 oz of ¼ strength hydrogen peroxide in normal saline for wound care TID for 2 days. Write the recipe.
Step A = Convert ounces to mL.
1 oz TID x 2 day = 6 oz
1oz/30 mL = 6 oz/ X
180 mL = X
Example
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings
Use method of choice.
Cancel units (oz).
Solve.

29. Preparing a Dilution from a Concentrate (cont.)
Step B Calculate. V = 180 mL, C = ¼ C x V = St ¼ x 180 mL = 45 mL of the solute (hydrogen peroxide) V – St = Sv 180 mL – 45 mL = 135 mL of the solvent (normal saline)
Example
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feeding
Set up problem – insert values.

30. Preparing a Dilution from a Concentrate (cont.)
The recipe is: Step C Since 45 is one fourth of the total volume of solution (180 mL) and = 180 mL, this answer is reasonable.
Example
¼ strength Hydrogen Peroxide – 180 mL
H2O mL
NS mL
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings

31. ½ hydrogen peroxide – 720 mL
Practice
Clean leg wound with 2 oz of ½ strength hydrogen peroxide in normal saline q6 h x 3 days. Write the recipe for total supply needed.
½ hydrogen peroxide – 720 mL
H2O mL
NS mL
ANSWER:
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for:
Topical solutions/irrigants
Enteral feedings
Step A Convert mL to oz 2 oz x 4 times/day x 3 days = 24 oz.
1 oz: 30 mL = 24 oz : X [cancel units (oz)]
720 mL = X
Step B Calculate.
C x V = St ½ x720 mL = 360 mL hydrogen peroxide (solute)
V - St = Sv 720 mL – 360 mL = 360 mL normal saline (solvent)
Step C 360 mL is half total volume, so it is reasonable.

32. Patient Education Mixing infant formulas
Know that most formulas have 20 calories / ounce.
Wash hands and top of formula can before starting.
Let cold water run for 2 minutes.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Some babies may need fewer calories.
Use clean measuring devices.
Reduce the amount of lead (do not use well water – may contain bacteria).

33. Patient Education When using liquid formulas
Check that label reads “concentrate”;
shake before opening;
follow recipe from AP;
pour formula concentrate into another container;
measure desired amount of water;
add to concentrate and mix well.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
A – Label should not read “ready-to-use.”
E – Use a clear liquid measuring cup.

34. Patient Education When using powdered formulas
follow instruction of AP;
measure desired amount of water;
check liquid level at eye level;
add level measures of formula powder;
use scoop provided;
mix or shake well.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
B – Use a liquid measuring cup.
C – Set cup on level surface to measure.
D – Do not pack powder into measuring device.
E – You may use measuring devices indented for dry ingredients.
F – Be sure lumps are gone.

35. Patient Education When storing formula
refrigerate in a covered container;
throw away unused prepared formula after 48 hours;
throw away unused formula powder one month after opening the can.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

36. Patient Education When feeding with formula shake formula well;
warm bottle;
do not use microwave;
shake bottle after warming;
test temperature of formula;
discard formula left in bottle after feeding.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
B – Warm bottle under warm tap water, or set bottle in a pan of warm water.
C – Microwave heats unevenly and can cause hot spots that might burn the baby’s mouth.
E – Test before feeding.

37. Label all patient tubing.
ERROR ALERT!
Label all patient tubing.
Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.
Eliminates errors that might occur when tubing is not marked
Reduces the chance of tube feedings being through an IV catheter