MCQ Quiz: Pharmaceutical Calculations and Compounding

Pharmaceutical calculations and compounding are critical skills in pharmacy practice, ensuring precise dosing and safe formulation of customized medications. This quiz covers dilution and concentration, alligation, isotonicity, milliequivalents, and non-sterile compounding techniques. It aligns with Pharm.D. curriculum standards and supports exam preparation for both academic and professional success.

1. What is the weight in grams of NaCl needed to make 100 mL of a 0.9% (w/v) solution?

  • A. 0.09 g
  • B. 0.9 g
  • C. 9 g
  • D. 1.8 g
    Correct answer: B. 0.9 g

2. What is the volume in mL of water needed to dilute 10 mL of a 10% solution to a 2% solution?

  • A. 30 mL
  • B. 40 mL
  • C. 50 mL
  • D. 60 mL
    Correct answer: C. 50 mL

3. The rule of alligation is used to:

  • A. Determine powder solubility
  • B. Convert metric units
  • C. Mix solutions of different concentrations
  • D. Calculate isotonic solutions
    Correct answer: C. Mix solutions of different concentrations

4. A preparation requires 20 mEq of KCl. If you have a 2 mEq/mL solution, how many mL are needed?

  • A. 5 mL
  • B. 10 mL
  • C. 20 mL
  • D. 40 mL
    Correct answer: B. 10 mL

5. Which of the following represents a weight/volume concentration?

  • A. mg/mg
  • B. mg/mL
  • C. g/g
  • D. mL/mL
    Correct answer: B. mg/mL

6. A patient receives 500 mg of a drug in 250 mL of solution over 2 hours. What is the infusion rate in mL/hr?

  • A. 100 mL/hr
  • B. 125 mL/hr
  • C. 250 mL/hr
  • D. 300 mL/hr
    Correct answer: B. 125 mL/hr

7. A 2% w/v solution contains how many mg/mL?

  • A. 2 mg/mL
  • B. 10 mg/mL
  • C. 20 mg/mL
  • D. 200 mg/mL
    Correct answer: C. 20 mg/mL

8. Which unit is used to express electrolyte concentration?

  • A. mg/mL
  • B. mEq/L
  • C. mol/mL
  • D. µg/dL
    Correct answer: B. mEq/L

9. Which of the following is a component of a suspension but not a solution?

  • A. Solute
  • B. Solvent
  • C. Suspending agent
  • D. Flavoring agent
    Correct answer: C. Suspending agent

10. The primary reference for compounding standards is:

  • A. FDA Code of Regulations
  • B. WHO Formulary
  • C. USP <795>
  • D. ISO 9001
    Correct answer: C. USP <795>

11. How many grams are in 2.5 kg?

  • A. 250 g
  • B. 2,500 g
  • C. 25,000 g
  • D. 250,000 g
    Correct answer: B. 2,500 g

12. What is the percentage strength of 5 g of drug in 250 mL of solution?

  • A. 1%
  • B. 2%
  • C. 3%
  • D. 4%
    Correct answer: A. 1%

13. Which of the following is a reason to use a geometric dilution technique?

  • A. To prevent drug interaction
  • B. To ensure uniform mixing of powders
  • C. To enhance solubility
  • D. To increase volume
    Correct answer: B. To ensure uniform mixing of powders

14. A prescription requires 120 mL of a 1:1000 epinephrine solution. How many mg of epinephrine are needed?

  • A. 0.12 mg
  • B. 1.2 mg
  • C. 12 mg
  • D. 120 mg
    Correct answer: C. 12 mg

15. An emulsion contains:

  • A. A solid dissolved in a liquid
  • B. Two immiscible liquids
  • C. A gas in a solid
  • D. A gas in a liquid
    Correct answer: B. Two immiscible liquids

16. A 5% dextrose solution contains how many grams of dextrose per 100 mL?

  • A. 0.5 g
  • B. 5 g
  • C. 50 g
  • D. 500 g
    Correct answer: B. 5 g

17. Which dosage form must be shaken before use?

  • A. Solution
  • B. Syrup
  • C. Suspension
  • D. Elixir
    Correct answer: C. Suspension

18. What is the main difference between creams and ointments?

  • A. Creams are water-based; ointments are oil-based
  • B. Creams are more occlusive
  • C. Ointments are used orally
  • D. Ointments contain alcohol
    Correct answer: A. Creams are water-based; ointments are oil-based

19. The calculation for mOsmol/L of NaCl (MW = 58.5) at 0.9% is:

  • A. 154
  • B. 300
  • C. 200
  • D. 100
    Correct answer: B. 300

20. An isotonic solution has the same osmolarity as:

  • A. Plasma
  • B. Stomach fluid
  • C. Saliva
  • D. Urine
    Correct answer: A. Plasma

21. A milliequivalent is defined as:

  • A. 1/1000 of an equivalent
  • B. Equivalent weight × 1000
  • C. Gram equivalent/volume
  • D. Molecular weight/valence
    Correct answer: A. 1/1000 of an equivalent

22. The concentration of 1:500 means:

  • A. 1 g in 500 mL
  • B. 1 mg in 500 mL
  • C. 1 part in 500 parts
  • D. 1 mL in 5 mL
    Correct answer: C. 1 part in 500 parts

23. Trituration is a technique used to:

  • A. Dissolve drugs
  • B. Reduce particle size of powders
  • C. Sterilize solutions
  • D. Prevent oxidation
    Correct answer: B. Reduce particle size of powders

24. How many mL are in 1.5 liters?

  • A. 150 mL
  • B. 1,500 mL
  • C. 15,000 mL
  • D. 150,000 mL
    Correct answer: B. 1,500 mL

25. A drug labeled 2% w/v contains how many grams in 250 mL?

  • A. 2 g
  • B. 4 g
  • C. 5 g
  • D. 10 g
    Correct answer: C. 5 g

26. A 10% solution is diluted 1:5. What is the new concentration?

  • A. 1%
  • B. 2%
  • C. 5%
  • D. 20%
    Correct answer: C. 2%

27. The purpose of a levigating agent is to:

  • A. Increase viscosity
  • B. Assist in mixing powders into ointment bases
  • C. Neutralize pH
  • D. Enhance bioavailability
    Correct answer: B. Assist in mixing powders into ointment bases

28. The formula weight of CaCl₂ is 110. How many mEq are in 1 gram? (valence = 2)

  • A. 10
  • B. 18.2
  • C. 5
  • D. 20
    Correct answer: B. 18.2

29. A prescription requires 3% hydrocortisone cream. If you mix 20 g of 5% with hydrophilic ointment, how much base is needed?

  • A. 20 g
  • B. 13.3 g
  • C. 10 g
  • D. 3 g
    Correct answer: B. 13.3 g

30. Which USP chapter governs non-sterile compounding?

  • A. <797>
  • B. <795>
  • C. <800>
  • D. <823>
    Correct answer: B. <795>

31. In pharmacy, a teaspoon (tsp) is equivalent to:

  • A. 2.5 mL
  • B. 5 mL
  • C. 10 mL
  • D. 15 mL
    Correct answer: B. 5 mL

32. What is the BUD (beyond-use date) for a water-containing oral formulation with no preservatives?

  • A. 24 hours
  • B. 14 days refrigerated
  • C. 30 days at room temperature
  • D. 60 days refrigerated
    Correct answer: B. 14 days refrigerated

33. The abbreviation “qs” means:

  • A. Quantity sold
  • B. Quick stir
  • C. Quantity sufficient
  • D. Quality standard
    Correct answer: C. Quantity sufficient

34. Which type of mortar and pestle is preferred for emulsions?

  • A. Glass
  • B. Wedgewood
  • C. Porcelain
  • D. Metal
    Correct answer: A. Glass

35. For calculating isotonicity, which method is commonly used?

  • A. Young’s Rule
  • B. Clark’s Rule
  • C. E-value method
  • D. Dilution factor
    Correct answer: C. E-value method

36. Which compounding form requires a PEG base?

  • A. Oral solution
  • B. Topical gel
  • C. Suppository
  • D. Capsule
    Correct answer: C. Suppository

37. Which agent stabilizes emulsions?

  • A. Flavor
  • B. Surfactant
  • C. Colorant
  • D. Base
    Correct answer: B. Surfactant

38. What is the purpose of lactose in capsule filling?

  • A. Solvent
  • B. Filler or diluent
  • C. Preservative
  • D. Buffer
    Correct answer: B. Filler or diluent

39. Triturates are:

  • A. Liquids
  • B. Divided powders
  • C. Tablets
  • D. Ointments
    Correct answer: B. Divided powders

40. Ultimately, pharmaceutical compounding aims to:

  • A. Create branded medications
  • B. Provide customized medication therapies to meet patient needs
  • C. Reduce pharmacy workload
  • D. Replace mass production
    Correct answer: B. Provide customized medication therapies to meet patient needs

41. The abbreviation “ad” in compounding instructions means:

  • A. After dinner
  • B. Up to
  • C. As directed
  • D. Administer daily
    Correct answer: B. Up to

42. What is the density of a liquid if 75 mL weighs 60 g?

  • A. 0.5 g/mL
  • B. 0.75 g/mL
  • C. 1.25 g/mL
  • D. 1.5 g/mL
    Correct answer: B. 0.75 g/mL

43. A pediatric dose is calculated using Clark’s Rule. What is the formula?

  • A. (Age/12) × Adult Dose
  • B. (Weight in kg × Adult Dose)/70
  • C. (Weight in lbs × Adult Dose)/150
  • D. Adult Dose × 0.5
    Correct answer: C. (Weight in lbs × Adult Dose)/150

44. Which component acts as an antioxidant in compounded preparations?

  • A. Propylene glycol
  • B. Sodium metabisulfite
  • C. Glycerin
  • D. Methylcellulose
    Correct answer: B. Sodium metabisulfite

45. What is the purpose of glycerin in suppository formulations?

  • A. Preservative
  • B. Plasticizer and humectant
  • C. Flavoring agent
  • D. Binder
    Correct answer: B. Plasticizer and humectant

46. What type of water is required for non-sterile compounding?

  • A. Tap water
  • B. Sterile water for injection
  • C. Purified water
  • D. Distilled water
    Correct answer: C. Purified water

47. When a drug is triturated in a liquid it is insoluble in, the resulting mixture is a:

  • A. Paste
  • B. Cream
  • C. Suspension
  • D. Solution
    Correct answer: C. Suspension

48. What is the final concentration if 30 mL of 20% solution is diluted to 60 mL?

  • A. 10%
  • B. 15%
  • C. 20%
  • D. 30%
    Correct answer: A. 10%

49. What is the metric equivalent of one grain (gr)?

  • A. 60 mg
  • B. 100 mg
  • C. 500 mg
  • D. 1,000 mg
    Correct answer: A. 60 mg

50. Which compounding record documents actual weights, lot numbers, and preparation steps?

  • A. Master formulation record
  • B. SDS (Safety Data Sheet)
  • C. Compounding log (or worksheet)
  • D. Certificate of analysis
    Correct answer: C. Compounding log (or worksheet)

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