Medication: For 100 g
Methyl salicylate 35 g
Menthol 15 g
Sodium stearate 13 g
Purified water 12 g
Propylene glycol 25 g
What is the ratio strength of propylene glycol in this
formulation?
25g / 100 g = 1:4 ratio
How many grams of sodium stearate are needed to
make 2.75 kg of this formulation?
13 g/ 100 g = x g / 2750 g
357.5 g
A drug suspension cost $128.31 per pint. What would a
week’s supply cost if a patient receives 1 tsp TID?
5mL x 3 doses/day x 7 days = 105 mL per week
$128.31 / 480 mL = x / 105 mL = $28.07
A 2mL vial of tobramycin sulfate contains 80 mg of
drug. How many mL of the injection should be
administered to obtain 0.01 g of tobramycin sulfate?
80mg / 2mL = 10mg / x mL
= 0.25 mL
From the following formula, calculate the number of
grams of each ingredient required to prepare 2 kg of an
ointment:
Precipitated sulfur 10g
Salicylic acid 2g
Hydrophilic ointment 88g
Precipated sulfur – 10g / 100g = x / 2000g = 200g
Salicylic acid – 2g / 100g = x / 2000g = 40g
Hydrophilic ointment – 88g / 100g = x / 2000g =
1760g
A physician orders a patient to receive 2 million
units of ampicillin in a 1000 mL bag of an IV
solution to be infused over 6 hours.
a) How many mL of solution will the patient receive
per hour?
1000mL / 6hr = x / 1 hr = 166.7mL/hr
b) How many units of ampicillin will the patient
receive per hour?
2,000,000 u / 6hr = x / 1 hr
= 333,333 u/hr
c) How many units of ampicillin will the patient
receive per minute?
2,000,000 u / 6 hr = u / 60 min = x / 1 min
= 5556 u/min
d) What is the flow rate in mL per minute?
1000 mL/ 360 min = x / 1 min
=2.78 mL/min
e) How many drops per hour would the patient
receive if the nurse uses an IV set that delivers 12
gtt/mL?
1000 mL / 6 hr = x / 1 hr = 166.7 mL/hr
12 gtt / mL = x / 166.7 mL = 2000 gtt/hr
f) How many units of ampicillin would be used in a
single drop of solution if an IV set delivering 12
gtt/mL is used?
12 gtt / 1mL = x / 1000 mL = 12,000 gtts
2,000,000 u / 12,000 gtt = x / 1 gtt
=166.7 u/gtt
Rx Ceclor 500mg. How many mL of a 375 mg/5 mL
Ceclor oral suspension would provide the prescribed
dose?
375 mg/5 mL = 500 mg / x
= 6.7 mL
The label on fluconazole oral suspension indicates that
24 mL of water should be added to the dry powder to
make 35mL of a solution containing 10 mg/mL.
a) What is the dry powder volume?
Final volume – diluents = dry powder volume
35 mL – 24 mL = 11 mL
b) How many grams of fluconazole would be
contained in a full bottle?
10 mg / 1 mL = x / 35 mL
= 350 mg = 0.35 g
c) How many mL should a 48lb child receive if the
package insert indicates the dose is 3 mg/kg?
1 kg = 2.2 lb = x / 48 lb
3 mg / 1 kg = x / 21.8 jg
10 mg / 1 mL = 65.4 mg / x
= 21.8 kg
= 65.4 mg
= 6.54 or 6.5mL