PTCB Sterile Compounding & Pharmacy Calculations 1 — Questions and Answers
Question 1: What type of environment is required for preparing sterile IV admixtures?
- Standard clean room
- Laminar airflow workbench (LAFW) or ISO 5 environment (Correct answer)
- Negative pressure room only
- Standard pharmacy counter with gloves
Correct answer: Laminar airflow workbench (LAFW) or ISO 5 environment
Sterile IV preparations must be prepared in an ISO 5 (Class 100) environment using a laminar airflow workbench to minimize contamination.
Question 2: How many milligrams are in 2 grams?
- 20 mg
- 200 mg
- 2000 mg (Correct answer)
- 20,000 mg
Correct answer: 2000 mg
There are 1,000 milligrams in 1 gram, so 2 grams = 2,000 mg.
Question 3: A vial contains 500 mg/10 mL. How many mL are needed to prepare a 250 mg dose?
- 2.5 mL
- 5 mL (Correct answer)
- 7.5 mL
- 10 mL
Correct answer: 5 mL
500 mg/10 mL = 50 mg/mL; 250 mg ÷ 50 mg/mL = 5 mL needed.
Question 4: What is the beyond-use date (BUD) for a low-risk sterile preparation stored at room temperature according to USP <797>?
- 12 hours
- 24 hours (Correct answer)
- 48 hours
- 30 days
Correct answer: 24 hours
USP <797> assigns low-risk sterile preparations a maximum BUD of 48 hours at controlled room temperature.
Question 5: Which type of hood is used for preparing hazardous sterile preparations (e.g., chemotherapy)?
- Horizontal laminar airflow workbench (LAFW)
- Biological safety cabinet (BSC) Class II (Correct answer)
- Vertical flow clean bench
- Positive pressure isolator
Correct answer: Biological safety cabinet (BSC) Class II
Hazardous sterile preparations require a Class II Biological Safety Cabinet (BSC) with vertical laminar flow and exhaust HEPA filtration to protect the preparer.
Question 6: A patient needs 1 L of D5W to infuse over 8 hours. What is the infusion rate in mL/hr?
- 100 mL/hr
- 125 mL/hr (Correct answer)
- 150 mL/hr
- 200 mL/hr
Correct answer: 125 mL/hr
1,000 mL ÷ 8 hours = 125 mL/hr infusion rate.
PTCB Sterile Compounding & Pharmacy Calculations 1
What type of environment is required for preparing sterile IV admixtures?