Calculations II: Compounding Exam Questions With
Complete Solutions
What is percent weight in weight? Correct Answers grams/100
...... ......
grams
What is percent weight in volume? Correct Answers grams/100
...... ......
mL
What is percent volume in volume? Correct Answers mL/100mL
...... ......
How many grams of NaCl are in 1 liter of normal saline? Correct ......
Answers - NaCl = 0.9%
.... ..
- 0.9% = 0.9g/100 mL
- 0.9g/100 mL = x/1000 mL = 9 grams
9 grams
How many grams of NaCl are in 500 mL of 1/2 NS? Correct ......
Answers 1/2 NS = 0.45% NaCl
.... ..
- 0.45% = 0.45g/100 mL
- 0.45g/100 mL = x/500 mL = 2.25 g
2.25 g
How many grams of dextrose are in 250 mL of D5W? Correct ......
Answers - D5W = 5% dextrose
.... ..
- 5% dextrose = 5 grams dextrose/100 mL
- 5g/100 mL = x/250 mL = 12.5 g
,12.5 grams dextrose
How many milligrams of triamcinolone should be used in
preparing the following prescription? Round to the nearest
whole number Correct Answers Triamcinolone (w/v) 5%
...... ......
Glycerin QS 60 mL
- Triamcinolone 5% = 5g/100 mL ---> need 60 mL total
- 5g/100 mL = x/60 = 3 grams
- 3 grams = 3000 milligrams
3000 milligrams
A prescription reads as follows: Prepare a 3% w/w coal tar
preparation; qs with petrolatum to 150 grams. How many grams
of petrolatum are required to compound the prescription. Round
to the nearest tenth. Correct Answers - 3% coal tar = 3 grams/100
...... ......
grams
- 3g/100 g = x/150 grams = 4.5 grams Triamcinolone
- 150 grams products - 4.5 grams triamcinolone = 145.5 grams
petrolatum
145 grams petrolatum
A pharmacist is compounding a vancomycin oral suspension.
The master formulation record says to reconstitute a 5 gram vial
of vancomycin powder with 50 mL of sterile water, then dilute
with sterile water to 200 mL. What is the final percentage
strength of the compounded product? Correct Answers - 5 grams
...... ......
vancomycin/200 mL water = 5/200 = 0.025
- Need percentage ---> 0.025*100 = 2.5%
, 2.5% final percentage
If 1250 grams of a mixture contains 80 grams of a drug, what is
the percentage strength of the mixture? Correct Answers - 80
...... ......
grams of drug/1250 final product = 0.064
- Need percentage ---> 0.064*100 = 6.4%
6.4%
A mouth rinse contains 1/12% (w/v) of chlorhexidine gluconate.
How many grams of chlorhexidine gluconate should be used to
prepare 18 liters of mouth rinse? Round to the nearest whole
number. Correct Answers - 1/12% = 0.0833 grams/100 mL
...... .... ..
- 18 liters = 18000 mL
- 0.0833/100 mL = x/18000 mL = 15 grams
15 grams
SS is a 79 year old female with dry mouth and dry eyes from
Sjogren's syndrome. She is picking up the prescription below.
What is the maximum millligrams of pilocarpine she will
receive per day?
Pilocarpine 1% w/v
Sodium Chloride qs ad 15 mL
Sig: 2 gtts (0.05 mL/gtt) po TID PRN up to 5 days for dry mouth
Correct Answers - Pilocarpine 1% w/v = 1 gram/100 mL
...... ......
- 1 gram/100 mL = x/15 mL = 0.15 grams
- 0.15 grams/15 mL = x/0.05 mL = 0.0005 grams per drop
- 0.0005 *6 drops = 0.003 grams per day = 3 milligrams per day
Complete Solutions
What is percent weight in weight? Correct Answers grams/100
...... ......
grams
What is percent weight in volume? Correct Answers grams/100
...... ......
mL
What is percent volume in volume? Correct Answers mL/100mL
...... ......
How many grams of NaCl are in 1 liter of normal saline? Correct ......
Answers - NaCl = 0.9%
.... ..
- 0.9% = 0.9g/100 mL
- 0.9g/100 mL = x/1000 mL = 9 grams
9 grams
How many grams of NaCl are in 500 mL of 1/2 NS? Correct ......
Answers 1/2 NS = 0.45% NaCl
.... ..
- 0.45% = 0.45g/100 mL
- 0.45g/100 mL = x/500 mL = 2.25 g
2.25 g
How many grams of dextrose are in 250 mL of D5W? Correct ......
Answers - D5W = 5% dextrose
.... ..
- 5% dextrose = 5 grams dextrose/100 mL
- 5g/100 mL = x/250 mL = 12.5 g
,12.5 grams dextrose
How many milligrams of triamcinolone should be used in
preparing the following prescription? Round to the nearest
whole number Correct Answers Triamcinolone (w/v) 5%
...... ......
Glycerin QS 60 mL
- Triamcinolone 5% = 5g/100 mL ---> need 60 mL total
- 5g/100 mL = x/60 = 3 grams
- 3 grams = 3000 milligrams
3000 milligrams
A prescription reads as follows: Prepare a 3% w/w coal tar
preparation; qs with petrolatum to 150 grams. How many grams
of petrolatum are required to compound the prescription. Round
to the nearest tenth. Correct Answers - 3% coal tar = 3 grams/100
...... ......
grams
- 3g/100 g = x/150 grams = 4.5 grams Triamcinolone
- 150 grams products - 4.5 grams triamcinolone = 145.5 grams
petrolatum
145 grams petrolatum
A pharmacist is compounding a vancomycin oral suspension.
The master formulation record says to reconstitute a 5 gram vial
of vancomycin powder with 50 mL of sterile water, then dilute
with sterile water to 200 mL. What is the final percentage
strength of the compounded product? Correct Answers - 5 grams
...... ......
vancomycin/200 mL water = 5/200 = 0.025
- Need percentage ---> 0.025*100 = 2.5%
, 2.5% final percentage
If 1250 grams of a mixture contains 80 grams of a drug, what is
the percentage strength of the mixture? Correct Answers - 80
...... ......
grams of drug/1250 final product = 0.064
- Need percentage ---> 0.064*100 = 6.4%
6.4%
A mouth rinse contains 1/12% (w/v) of chlorhexidine gluconate.
How many grams of chlorhexidine gluconate should be used to
prepare 18 liters of mouth rinse? Round to the nearest whole
number. Correct Answers - 1/12% = 0.0833 grams/100 mL
...... .... ..
- 18 liters = 18000 mL
- 0.0833/100 mL = x/18000 mL = 15 grams
15 grams
SS is a 79 year old female with dry mouth and dry eyes from
Sjogren's syndrome. She is picking up the prescription below.
What is the maximum millligrams of pilocarpine she will
receive per day?
Pilocarpine 1% w/v
Sodium Chloride qs ad 15 mL
Sig: 2 gtts (0.05 mL/gtt) po TID PRN up to 5 days for dry mouth
Correct Answers - Pilocarpine 1% w/v = 1 gram/100 mL
...... ......
- 1 gram/100 mL = x/15 mL = 0.15 grams
- 0.15 grams/15 mL = x/0.05 mL = 0.0005 grams per drop
- 0.0005 *6 drops = 0.003 grams per day = 3 milligrams per day
