Pharmacy Compounding 5 — Questions and Answers
Question 1: Which emulsifying agent is an example of a cationic surfactant used in compounding?
- Sodium lauryl sulfate
- Benzalkonium chloride (Correct answer)
- Polysorbate 80 (Tween 80)
- Lecithin
Correct answer: Benzalkonium chloride
Benzalkonium chloride is a cationic (positively charged) quaternary ammonium surfactant also used for its antimicrobial properties.
Question 2: A compounded preparation is described as a 'W/O emulsion.' This means:
- Water is the dispersed phase and oil is the continuous phase (Correct answer)
- Oil is the dispersed phase and water is the continuous phase
- Water and oil are mixed without an emulsifier
- Water is supersaturated with an oil-soluble drug
Correct answer: Water is the dispersed phase and oil is the continuous phase
In a W/O (water-in-oil) emulsion, water droplets are dispersed within the oil continuous phase.
Question 3: Which pH range is generally considered most appropriate for a compounded ophthalmic preparation to minimize irritation?
- 3.0–5.0
- 5.0–6.5
- 6.5–7.5 (Correct answer)
- 8.0–9.5
Correct answer: 6.5–7.5
The tear film pH is approximately 7.4, so ophthalmic preparations are buffered to a pH of 6.5–7.5 to minimize irritation.
Question 4: A 503B outsourcing facility differs from a 503A compounding pharmacy primarily because 503B facilities:
- Only compound for veterinary use
- May compound without patient-specific prescriptions in larger quantities for office stock (Correct answer)
- Are exempt from all FDA inspections
- Cannot compound sterile preparations
Correct answer: May compound without patient-specific prescriptions in larger quantities for office stock
503B outsourcing facilities may produce larger batches for office stock without patient-specific prescriptions but must register with the FDA and follow CGMP standards.
Question 5: When compounding a transdermal gel using PLO (Pluronic Lecithin Organogel), the lecithin component serves primarily as:
- A preservative
- A penetration enhancer that increases skin permeation (Correct answer)
- A thickening agent
- An antioxidant
Correct answer: A penetration enhancer that increases skin permeation
Lecithin in PLO gels acts as a penetration enhancer by interacting with skin lipids to facilitate transdermal drug delivery.
Question 6: Which type of balance is required when weighing quantities less than 120 mg in a pharmacy compounding setting?
- Class A prescription balance
- Torsion balance
- Triple beam balance
- Electronic analytical balance (Correct answer)
Correct answer: Electronic analytical balance
An electronic analytical balance capable of measuring below 120 mg with appropriate sensitivity is required when quantities fall below the minimum weighable quantity of a Class A balance.
Question 7: Stability testing during compounding quality assurance most commonly evaluates which parameters? (Select the best answer)
- Color, odor, pH, and drug concentration over time (Correct answer)
- Only the appearance and smell
- Sterility and endotoxin levels only
- Container closure integrity only
Correct answer: Color, odor, pH, and drug concentration over time
Comprehensive stability testing evaluates physical (color, odor, appearance), chemical (pH, drug concentration), and microbiological parameters over the assigned BUD period.
Pharmacy Compounding 5
Which emulsifying agent is an example of a cationic surfactant used in compounding?