Pharmacy Calculation & Compounding

A 70-kg adult needs amoxicillin 40 mg/kg/day divided q8h; how many mg per dose?

Infuse 500 mL normal saline over 4 hours; what mL/hour?

From a 10 mg/mL stock, prepare 250 mL of 2 mg/mL; how much stock is needed?

A solution has 25 g drug in 500 mL; what is % w/v?

Convert ratio strength 1:500 (w/v) to percentage.

How many mEq of Na+ are in 1 g of NaCl? (MW 58.5; monovalent)

Calculate osmolarity of D5W (5% dextrose). (MW 180; i=1)

A 1% drug (E=0.18) needs to be isotonic (0.9% NaCl). What % NaCl to add?

Mix 95% and 30% alcohol to make 1,000 mL of 70%. How much 95%?

A vial is reconstituted to 100 mg/mL. How many mL for a 750 mg dose?

A 64-kg, 160-cm patient needs 100 mg/m². Mosteller BSA?

Infuse 250 mL at 75 mL/h; how long will it take?

Dopamine 400 mg in 250 mL; rate 15 mL/h. What mg/h?

A 20% w/w ointment—how many mg API in 30 g?

Convert 1:1000 (w/v) epinephrine to mg/mL.

Prepare 10 mL of 1:10,000 from 1:1,000. How much stock?

Best method to incorporate a hydrophobic powder into an ointment base evenly:

BUD for water-containing oral nonsterile prep (USP <795>):

BUD for non-aqueous nonsterile prep (USP <795>):

BUD for water-containing topical/dermal nonsterile prep:

Correct garbing order before sterile compounding:

In a laminar airflow workbench, place critical work at least:

HEPA filters nominally remove:

How many mEq are in 20 mL of KCl 10% (w/v)? (KCl MW ≈74.5; monovalent)

How much NaCl to add to 30 mL of 2% drug (E=0.23) to make isotonic?

What is the osmolarity of 0.45% NaCl? (MW 58.5; i≈2)

Convert a KCl order of 20 mEq to mg KCl.

A macrodrip set is 20 gtt/mL. Infuse 1 L over 8 h; gtt/min?

Mix 250 mL of 10% with 750 mL of 5%; final % w/v?

A 15 mg/kg vancomycin dose for 86-kg adult equals:

Prepare 60 g of 0.5% HC ointment using 1% and 0.25% bases; grams of 1%?

A liquid has SG 1.20. What does 150 mL weigh?

Convert 25 mg/mL to % w/v.

Convert 0.1% w/w cream to mg of drug per gram.

Pharmacy receives 250 mg/mL stock; need 100 mL of 25 mg/mL. How much stock and diluent?

A TPN contains NaCl 23.4% (w/v). How many mEq Na+ in 10 mL? (NaCl MW 58.5)

If 30 g of powder occupies 60 mL, what is its bulk density?

A syrup requires 850 mL of 60% sucrose (w/v). How many grams sucrose?

To evenly mix 1 g of potent API with 99 g lactose, which technique?

A 1,000 mL bag has 20 mEq KCl and 10 mEq MgSO₄. What is total mOsm added (assume full dissociation; KCl i≈2, MgSO₄ i≈2)?

Convert a ratio strength of 2:1000 (w/v) to percent strength and mg/mL.

How many milliliters of 25% w/v dextrose provide 30 g dextrose?

A stock is 50 mg/mL. What volume supplies a 15 mg dose?

To prepare 10 mL of a 10 mg/mL suspension from 50 mg tablets, how many tablets are needed?

Make 60 g of 2.5% ointment by mixing 1% and 4% bases. How much of each?

Using 20% and 5% solutions to prepare 200 mL of 12%: how much 20% is required?

Amoxicillin 90 mg/kg/day divided q12h for an 18-kg child—mg per dose?

Estimate CrCl (Cockcroft–Gault) for a 72-year-old male, 80 kg, SCr 1.6 mg/dL.

Calculate ANC: WBC 3.6×10⁹/L; neutrophils 55%; bands 8%.

How many mg NaCl are needed to make 250 mL of 0.9% NaCl?

Isotonic adjustment: 30 mL of a 1% solution (drug E = 0.08). How much NaCl to add to make it isotonic?

What is the osmolarity of 3% NaCl?

How many grams of dextrose are in 500 mL of 20% w/v mannitol? (concept: % calculation)

1.25 g vancomycin in 250 mL over 90 min—what infusion rate in mL/h?

How many mL of 1:1000 epinephrine are needed to prepare 50 mL of 1:10,000?

Six 2-g suppositories each must contain 300 mg drug (DF = 1.5). How much base is required?

Make thirty size #2 capsules (capacity 300 mg) each with 75 mg API; how much lactose filler total?

Convert 70% v/v ethanol to proof (U.S.).

How many mEq of Ca²⁺ are in 1 g of CaCl₂·2H₂O? (MW ≈147; valence 2)

What filter pore size is used for sterilizing filtration of solutions?

Under USP <797>, typical BUD for low-risk CSP at controlled room temperature is:

Typical BUD for medium-risk CSP at room temperature is:

Typical BUD for high-risk CSP at room temperature is:

Minimum recommended hand/forearm wash time before garbing for sterile compounding:

Heparin 25,000 units in 250 mL (100 U/mL) at 12 U/kg/h for 72-kg patient—what mL/h?

How many mL of D50W are needed to deliver 100 g dextrose?

To give atropine 1 mg IV from 0.1 mg/mL in a 10 mL syringe, what volume is required?

Amoxicillin 90 mg/kg/day ÷ BID for 12-kg child; suspension 250 mg/5 mL—what mL per dose?

What is the % w/w of an ointment containing 45 mg API in 30 g total?

Grams of NaCl needed to prepare 500 mL of 0.1 M NaCl (MW 58.5)?

Microdrip (60 gtt/mL) at 42 mL/h—what is the drip rate?

Suspension 100 mg/5 mL; order 12.5 mg/kg q8h for a 16-kg child—what mL per dose?

How many mg drug in 10 g of a 5% w/w cream?

Mixing 0.9% NaCl with sterile water to make 0.45% NaCl requires which ratio?

Reconstitute 1 g cefazolin to 100 mg/mL, then dilute entire dose to 50 mL. Final concentration?

Calculate BSA (Mosteller) for 180 cm, 100 kg.

When compounding a eutectic mixture (e.g., menthol + camphor), the best technique is:

How many 5 mg tablets are needed to prepare 150 mL of a 1 mg/mL suspension?

Convert a ratio strength of 1:1,000,000 to parts per million (ppm).

How many mL of 1:1000 are needed to prepare 250 mL of 1:2000?

Convert 0.25 grain to milligrams (use 1 grain ≈ 65 mg).

From a 10 mg/mL stock, prepare 250 mL of 0.02% solution; how much stock and diluent?

Make 200 g of 1% ointment using 2% and 0.25% bases; grams of each?

KCl 2 mEq/mL vial: what volume provides 30 mEq?

How many mEq of bicarbonate are in 50 mL of 8.4% NaHCO₃?

Infuse 750 mL at 125 mL/h; total infusion time?

1 L over 10 hours via 15 gtt/mL set—what drip rate (gtt/min)?

Approximate osmolarity of 2% NaCl (i≈2; MW 58.5)?

Isotonic adjustment: 30 mL of 1% drug (E=0.12) to 0.9% NaCl—how much NaCl?

Grams of NaCl to make 250 mL of 3 M NaCl?

mEq of Na⁺ in 250 mL of 3% NaCl?

Deliver 1 mg/min from 2 mg/mL solution—infusion rate?

Microdrip set (60 gtt/mL) at 30 mL/h—what gtt/min?

Prepare 100 capsules each 50 mg API; capsule fill 250 mg—total lactose?

Ten 2-g suppositories each with 300 mg drug; drug DV=2. Base required?

Ratio strength 1:4000 equals how many mg/mL?

Mix 80% and 20% alcohol to make 500 mL of 30%—volume of 80%?

To minimize Ca–phosphate precipitation in TPN, which step is correct?

Gentamicin 7 mg/kg for a 65-kg adult—dose?

Calories from 250 mL of D50W (parenteral dextrose 3.4 kcal/g)?

Calories from 250 mL IV lipid 20%?

How many mEq Mg²⁺ in 2 mL of 50% magnesium sulfate (MW≈246.5; valence 2)?

Approximate osmolarity of D10W?

Dopamine 400 mg/250 mL (1.6 mg/mL) at 5 mcg/kg/min for 70 kg—mL/h?

A compound expected 100 g yields 92 g; percent yield?

With SR=6 mg and max 5% error, minimum weighable quantity (MWQ)?

How many mg lidocaine are in 12 mL of 1% solution?

Prepare 1000 mL of 70% v/v alcohol from 95%; volume of 95% needed?

A 25 mcg/h transdermal patch delivers how much drug per day?

Approximate osmolarity of D5 0.45% NaCl?

How much drug is needed to prepare 250 mL of a 1:100 solution?

How many mL of morphine 2 mg/mL for a 6 mg dose?

Volume of 23.4% NaCl to make 300 mL of 0.9%?

Convert ratio 1:250 to % w/v.

Rate to deliver 20 mg/h from 5 mg/mL solution?

Chemo order: 500 mg/m²; BSA 1.9 m²—total dose?

How many millimoles correspond to 40 mEq of K⁺?

mEq of Na⁺ in 1 g NaHCO₃ (MW 84; valence 1)?

From 10% w/v stock, prepare 120 mL of 2%—how much stock?

How many mg of drug are in 250 mL of 0.5% w/v?

Convert a ratio strength of 1:2500 (w/v) to percent strength and mg/mL.

How many milliliters of 70% alcohol are needed to prepare 400 mL of 8% (v/v) using water as diluent?

An 22-kg child needs amoxicillin 45 mg/kg/day divided q8h. How many mg per dose?

How many milliliters of 23.4% NaCl are required to make 500 mL of 0.9% NaCl?

How many mEq of K⁺ are in 15 mL of KCl 10% w/v? (MW 74.5; monovalent)

Approximate osmolarity of 2.5% dextrose in water (D2.5W). (MW 180; i=1)

Using 70% and 5% dextrose, how much 70% is needed to prepare 150 mL of 35%?

Set is 15 gtt/mL. Infuse 750 mL over 6 hours. What is the drip rate?

How many 250-mg capsules are needed to prepare 200 mL of a 20 mg/mL suspension?

From a 2.5 mg/mL stock, what volume provides a 0.5 mg dose?

Convert 0.25% w/v to mg/mL.

A drug is dosed 150 mg/m²; BSA is 1.73 m². What dose?

Heparin 25,000 units in 250 mL (100 U/mL). Infuse 900 U/h. What mL/h?

A TPN contains 40 g amino acids, 150 g dextrose, and 50 g IV lipid. Total kcal?

Make 20 mL of a 2% solution isotonic (0.9% NaCl), drug E=0.18. How much NaCl to add?

Approximate osmolarity of 0.9% NaCl.

How many mEq of Na⁺ are in 650 mg of NaHCO₃? (MW 84; valence 1)

Prepare 120 g of 2% ointment using 10% and 1% bases. How much 10% is needed?

A torsion balance has a sensitivity requirement (SR) of 10 mg. With a 5% error limit, what is the MWQ?

Vancomycin 1,250 mg in 250 mL over 2 hours. What rate in mL/h?

How many grams of amino acids are in 1,500 mL of AA 8.5%?

How many milligrams of drug are in 30 mL of a 0.02% solution?

Convert 1:2000 (w/v) to percent and mg/mL.

Using 50% and 10% solutions to make 400 mL of 12%: how much 50% is required?

How many mEq of Na⁺ are in 2 g of NaCl? (MW 58.5)

How many milliliters of 20% IV lipid (≈2 kcal/mL) provide 500 kcal?

How many milligrams of drug are needed to prepare 60 g of 0.1% w/w cream?

Convert an infusion order of 0.04 mg/kg/min for a 70-kg adult to mg/h.

How many mEq of K⁺ in 20 mL of KCl 2 mEq/mL?

A solution contains 400 mg drug in 250 mL (1.6 mg/mL). Deliver 10 mg/h. What mL/h?

Final % w/v after mixing 100 mL of 2% with 400 mL of 0.5%?

Insulin infusion bag is 1 unit/mL. Needed rate is 6 units/h. What mL/h?

Approximate osmolarity when 1 g of anhydrous CaCl₂ is dissolved in 1 L (MW 111; i≈3).

How many milligrams of CaCl₂·2H₂O provide 12 mEq of Ca²⁺? (MW ≈147; valence 2)

Volume of 25% mannitol needed to provide 12.5 g mannitol?

For 15 mL of a 1% solution (drug E=0.09), how much NaCl to make isotonic?

A liquid weighs 60 g per 50 mL. What is its specific gravity?

What is the final K⁺ concentration (mEq/L) if 30 mEq KCl is added to 250 mL of fluid?

How many mg/mL result when 500 mg drug is added to 1 liter of solution?

Estimate CrCl (Cockcroft–Gault) for a 65-year-old female, 60 kg, SCr 1.0 mg/dL.

How many grams of NaHCO₃ are needed to provide 150 mEq? (MW 84; valence 1)

Using a 20 gtt/mL set, what drip rate (gtt/min) gives 75 mL/h?

A 500-mg dry-powder vial is reconstituted to make 50 mg/mL. What final volume?

Using 25% and 5% solutions to prepare 300 mL of 10%: how much 25% is required?

How many milliliters of D10W are needed to deliver 25 g dextrose?

Approximate osmolarity of 0.225% NaCl (¼NS). (MW 58.5; i≈2)

A 1:500 solution is infused at 0.2 mL/h. How many mg/h are delivered?

How many milligrams of epinephrine are in 3 mL of 1:1000?

What volume of 10 mg/mL stock is needed to prepare 250 mL of 1 mg/mL?

How many grams of NaCl are contained in 3 liters of 0.45% NaCl?

For 50 mL of 0.3% solution (E=0.20), how much NaCl to make isotonic?

How many milliliters of 70% isopropyl alcohol are needed to make 250 mL of 30%?

How many milligrams of drug are in 45 mL of a 1:5000 solution?

Using a microdrip (60 gtt/mL), what gtt/min equals 18 mL/h?

A liquid weighs 132 g per 100 mL. What is the specific gravity?

A solution is 2 mg/mL and the drop factor is 20 gtt/mL. How many mg are delivered per drop?

Approximately how many milligrams of sodium are in 1 g of NaCl? (Na atomic wt ≈23; NaCl MW 58.5)

A suspension is 250 mg/5 mL. What volume provides 180 mg?

An antibiotic 2 g in 100 mL is infused over 30 minutes. What mL/h rate?

Prepare 200 g of 12% ointment using 20% and 5% bases. How much 20% is needed?