Pharmaceutical Calculations and Compounding Flashcards
6 cards from real Pharm.D. Doctor of Pharmacy practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Pharmaceutical Calculations and Compounding flashcards as text
A vial contains 40 mg/mL of a drug. The order calls for 0.5 mg/kg for a 60 kg patient. How many mL should be drawn up?
Answer: 0.75 mL
Dose = 0.5 mg/kg × 60 kg = 30 mg; Volume = 30 mg ÷ 40 mg/mL = 0.75 mL.
An IV drip order reads: 500 mg in 250 mL NS to infuse over 4 hours via a 20 gtt/mL tubing set. What is the drip rate in gtt/min?
Answer: 21 gtt/min
Flow rate = (250 mL × 20 gtt/mL) ÷ (4 hrs × 60 min/hr) = 5,000 ÷ 240 ≈ 20.8 ≈ 21 gtt/min.
Which compounding standard governs sterile preparations such as IV admixtures in the United States?
Answer: USP
USP establishes standards for compounding sterile preparations, including IV admixtures, ophthalmic preparations, and other parenteral products.
To prepare a pediatric suspension, a pharmacist triturates a tablet with a small amount of liquid before q.s. to final volume. This initial trituration step is called:
Answer: Geometric dilution with vehicle
Geometric dilution (or incorporation with a small vehicle) ensures uniform distribution of the active ingredient before adding the full volume, preventing concentration errors.
What is the percentage strength of a solution made by dissolving 5 g of a drug in sufficient water to make 200 mL?
Answer: 2.5%
% w/v = (5 g ÷ 200 mL) × 100 = 2.5%.
Which ingredient classification in a compounded preparation serves as the vehicle or base?
Answer: Excipient
Excipients (including vehicles, bases, binders, and fillers) are inactive ingredients that provide the physical form of the preparation and carry the API.