MCQ Quiz: Rectal Drug Delivery

Rectal drug delivery is a specialized route used for both systemic and local action. This route offers advantages such as bypassing hepatic first-pass metabolism, suitability for pediatric or unconscious patients, and localized treatment of anorectal conditions. This MCQ quiz covers rectal dosage forms, pharmacokinetics, formulation factors, patient counseling, and clinical applications—essential for Pharm.D. students.

1. Which of the following is a primary rectal dosage form?

• A. Capsule
• B. Suppository
• C. Tablet
• D. Elixir
  Correct answer: B. Suppository

2. What is a major advantage of rectal administration?

• A. Slower drug onset
• B. Avoids systemic absorption
• C. Bypasses some hepatic first-pass metabolism
• D. Requires swallowing
  Correct answer: C. Bypasses some hepatic first-pass metabolism

3. Which drug is commonly administered rectally to reduce fever?

• A. Ciprofloxacin
• B. Acetaminophen
• C. Omeprazole
• D. Salbutamol
  Correct answer: B. Acetaminophen

4. Rectal drug delivery is most appropriate in which situation?

• A. Oral administration is preferred
• B. Patient is vomiting
• C. When taste is a concern
• D. For dry skin
  Correct answer: B. Patient is vomiting

5. What base is commonly used in suppository formulations?

• A. Ethanol
• B. Glycerol
• C. Cocoa butter (theobroma oil)
• D. Cellulose
  Correct answer: C. Cocoa butter (theobroma oil)

6. Which of the following is a systemic use of rectal administration?

• A. Treating skin infections
• B. Relieving joint pain
• C. Managing seizures with diazepam
• D. Removing warts
  Correct answer: C. Managing seizures with diazepam

7. Which factor most influences drug absorption via the rectum?

• A. Stomach pH
• B. Colon bacteria
• C. Suppository base melting and spreading
• D. Drug taste
  Correct answer: C. Suppository base melting and spreading

8. What is the typical shape of a rectal suppository?

• A. Disc
• B. Rod or torpedo
• C. Capsule
• D. Bead
  Correct answer: B. Rod or torpedo

9. Rectal formulations are administered through:

• A. Inhalation
• B. Nasal drops
• C. The anus
• D. The vagina
  Correct answer: C. The anus

10. A common indication for rectal enemas is:

• A. Bronchitis
• B. Constipation relief
• C. Headache
• D. Asthma
  Correct answer: B. Constipation relief

11. Which excipient is used to harden suppositories?

• A. Talc
• B. Stearic acid
• C. Beeswax
• D. Sodium lauryl sulfate
  Correct answer: C. Beeswax

12. Which type of base is water-soluble and used for heat-stable drugs?

• A. Cocoa butter
• B. Glycerinated gelatin
• C. Waxes
• D. Paraffin
  Correct answer: B. Glycerinated gelatin

13. What is the disadvantage of using glycerin as a suppository base?

• A. Requires refrigeration
• B. Causes mucosal irritation
• C. Poor melting properties
• D. Low bioavailability
  Correct answer: B. Causes mucosal irritation

14. A formulation inserted rectally to cleanse the bowel is a:

• A. Suppository
• B. Microemulsion
• C. Enema
• D. Transdermal patch
  Correct answer: C. Enema

15. The melting point of cocoa butter is close to:

• A. 25°C
• B. 34–36°C (body temperature)
• C. 45°C
• D. 10°C
  Correct answer: B. 34–36°C (body temperature)

16. How do rectal drugs partially avoid first-pass metabolism?

• A. By dissolving in bile
• B. Through absorption in lower hemorrhoidal veins
• C. Via colonic fermentation
• D. Through the stomach lining
  Correct answer: B. Through absorption in lower hemorrhoidal veins

17. What is a limitation of rectal administration?

• A. Cannot use for systemic effect
• B. Taste sensitivity
• C. Patient discomfort and poor acceptance
• D. Cost
  Correct answer: C. Patient discomfort and poor acceptance

18. Which rectal dosage form is used for inflammatory bowel disease?

• A. Capsule
• B. Tablet
• C. Suppository or foam
• D. Ointment
  Correct answer: C. Suppository or foam

19. What is the function of surfactants in rectal suppositories?

• A. Flavor masking
• B. Reduce surface tension and improve drug release
• C. Lower cost
• D. Add color
  Correct answer: B. Reduce surface tension and improve drug release

20. The retention time of a rectal drug affects:

• A. Drug potency
• B. Drug stability
• C. Extent of absorption
• D. Color of the base
  Correct answer: C. Extent of absorption

21. Which drug is frequently used rectally for antiemetic effect?

• A. Paracetamol
• B. Metoclopramide
• C. Aspirin
• D. Morphine
  Correct answer: B. Metoclopramide

22. Suppository bases should be:

• A. Colored and flavored
• B. Lipophilic and melt at body temperature
• C. Dry and gritty
• D. Insoluble in water
  Correct answer: B. Lipophilic and melt at body temperature

23. What affects the distribution of drug from a melted suppository?

• A. Density of the drug
• B. Patient’s diet
• C. Ambient humidity
• D. Suppository color
  Correct answer: A. Density of the drug

24. When is a rectal route particularly useful in pediatric care?

• A. Drug has a bitter taste
• B. Tablet administration is easier
• C. When vomiting prevents oral administration
• D. When IV access is immediate
  Correct answer: C. When vomiting prevents oral administration

25. Which factor reduces rectal drug absorption?

• A. Drug solubility
• B. Presence of fecal matter
• C. Mucoadhesive polymers
• D. Lipophilicity
  Correct answer: B. Presence of fecal matter

26. A hydrophilic drug in a lipophilic base exhibits:

• A. Slow release
• B. Enhanced release
• C. Delayed melting
• D. No absorption
  Correct answer: B. Enhanced release

27. Glycerin suppositories act primarily as:

• A. Systemic anti-inflammatories
• B. Local laxatives
• C. Antibiotics
• D. Hormones
  Correct answer: B. Local laxatives

28. A patient unable to tolerate oral medications due to GI upset may be given:

• A. Rectal dosage form
• B. IV fluid
• C. Intranasal tablets
• D. Eye drops
  Correct answer: A. Rectal dosage form

29. A clear, fluid rectal product for delivering drugs or hydration is a:

• A. Suppository
• B. Gel
• C. Solution enema
• D. Paste
  Correct answer: C. Solution enema

30. Which base is best avoided for heat-sensitive drugs?

• A. Glycerinated gelatin
• B. Cocoa butter
• C. Polyethylene glycol (PEG)
• D. Polysorbates
  Correct answer: B. Cocoa butter

31. The rate of drug release from rectal dosage forms is influenced by:

• A. Drug color
• B. Route of insertion
• C. Base composition and drug solubility
• D. Tablet hardness
  Correct answer: C. Base composition and drug solubility

32. The main site of drug absorption in rectal delivery is:

• A. Small intestine
• B. Large intestine
• C. Rectal mucosa
• D. Esophagus
  Correct answer: C. Rectal mucosa

33. Rectal absorption is more erratic than oral due to:

• A. Blood flow variability and local conditions
• B. Rapid GI transit
• C. Enzyme deficiency
• D. Air exposure
  Correct answer: A. Blood flow variability and local conditions

34. Which factor increases rectal drug absorption?

• A. Solid feces
• B. Suppository leakage
• C. Proper base selection and retention
• D. Cold ambient temperature
  Correct answer: C. Proper base selection and retention

35. A high lipophilic drug in PEG base may:

• A. Dissolve poorly
• B. Release quickly
• C. Be retained long
• D. Improve solubility
  Correct answer: B. Release quickly

36. Suppositories are manufactured by:

• A. Spray drying
• B. Solvent casting
• C. Fusion molding
• D. Direct compression
  Correct answer: C. Fusion molding

37. A patient should be counseled to store suppositories:

• A. At room temperature
• B. In a humid area
• C. In the refrigerator (if cocoa butter base)
• D. In sunlight
  Correct answer: C. In the refrigerator (if cocoa butter base)

38. Which is a sign of improper suppository storage?

• A. Hardening
• B. Melting or deformation
• C. Loss of color
• D. Dryness
  Correct answer: B. Melting or deformation

39. When inserting a rectal suppository, the pointed end should:

• A. Go in last
• B. Be cut
• C. Enter first
• D. Be lubricated with alcohol
  Correct answer: C. Enter first

40. Rectal drug delivery is especially useful when:

• A. Rapid oral absorption is possible
• B. Parenteral access is available
• C. Drug degradation occurs in stomach
• D. Taste is the main concern
  Correct answer: C. Drug degradation occurs in stomach

41. The ideal volume for a retention enema in adults is:

• A. 5–10 mL
• B. 50–100 mL
• C. 200–500 mL
• D. >1 L
  Correct answer: C. 200–500 mL

42. Suppositories should be inserted:

• A. Immediately after defecation
• B. After meals
• C. On a full stomach
• D. With alcohol
  Correct answer: A. Immediately after defecation

43. What is the purpose of mucoadhesive polymers in rectal gels?

• A. Add color
• B. Enhance retention and absorption
• C. Increase pain
• D. Prevent systemic absorption
  Correct answer: B. Enhance retention and absorption

44. Which rectal dosage form is used for both diagnostic and therapeutic use?

• A. Suppository
• B. Foam
• C. Enema
• D. Lotion
  Correct answer: C. Enema

45. Ultimately, rectal dosage forms are designed to:

• A. Replace oral therapy
• B. Bypass oral limitations and provide local/systemic effect when oral or IV is unsuitable
• C. Improve color
• D. Avoid excipients
  Correct answer: B. Bypass oral limitations and provide local/systemic effect when oral or IV is unsuitable

46. Which of the following rectal dosage forms is typically foam-based and used in inflammatory bowel disease?

• A. Suppository
• B. Rectal foam
• C. Oral emulsion
• D. Sublingual spray
  Correct answer: B. Rectal foam

47. A major counseling point for rectal administration is to:

• A. Eat before insertion
• B. Use immediately after refrigeration
• C. Wash hands before and after use
• D. Always insert two suppositories
  Correct answer: C. Wash hands before and after use

48. For a rectal drug to act locally, it should:

• A. Be highly lipid soluble
• B. Be quickly absorbed systemically
• C. Remain in the rectum for targeted action
• D. Have enteric coating
  Correct answer: C. Remain in the rectum for targeted action

49. Which rectal formulation is ideal for rapid hydration and laxative action?

• A. PEG suppository
• B. Glycerin gel
• C. Isotonic solution enema
• D. Rectal foam
  Correct answer: C. Isotonic solution enema

50. The rectal route is particularly useful in geriatric and pediatric patients due to:

• A. Pleasant taste
• B. Easy insertion
• C. Difficulty swallowing and reduced cooperation for oral intake
• D. Lower absorption
  Correct answer: C. Difficulty swallowing and reduced cooperation for oral intake