Drug absorption is a fundamental pharmacokinetic process that influences how quickly and efficiently a drug enters systemic circulation. Factors such as drug formulation, physicochemical properties, and route of administration determine absorption rate and extent. This MCQ quiz is tailored for Pharm.D. students, aligned with topics from courses like PHA5176 and PHA5439.
1. What is drug absorption?
- A. Distribution of drug to tissues
- B. Metabolism of drug in the liver
- C. Movement of drug from site of administration into systemic circulation
- D. Elimination of drug from the body
Correct answer: C. Movement of drug from site of administration into systemic circulation
2. Which route of administration results in the fastest absorption?
- A. Oral
- B. Intramuscular
- C. Intravenous
- D. Sublingual
Correct answer: C. Intravenous
3. The main site for drug absorption after oral administration is:
- A. Mouth
- B. Stomach
- C. Small intestine
- D. Large intestine
Correct answer: C. Small intestine
4. What factor most influences passive diffusion of drugs?
- A. Enzyme affinity
- B. Drug ionization and lipophilicity
- C. Drug color
- D. Particle shape
Correct answer: B. Drug ionization and lipophilicity
5. Which physicochemical property enhances drug permeability across biological membranes?
- A. Hydrophilicity
- B. High ionization
- C. Lipophilicity
- D. Large molecular weight
Correct answer: C. Lipophilicity
6. The rate-limiting step in the absorption of a poorly soluble drug is usually:
- A. Metabolism
- B. Dissolution
- C. Distribution
- D. Protein binding
Correct answer: B. Dissolution
7. Which of the following factors decreases oral drug absorption?
- A. High lipophilicity
- B. Non-ionized state
- C. Presence of food altering GI pH
- D. Small molecular size
Correct answer: C. Presence of food altering GI pH
8. Which form of a drug is best absorbed in the gastrointestinal tract?
- A. Highly ionized form
- B. Unionized and lipophilic form
- C. Hydrophilic and large
- D. Highly protein-bound form
Correct answer: B. Unionized and lipophilic form
9. Which parameter represents the rate of drug absorption?
- A. Cmax
- B. Tmax
- C. AUC
- D. Vd
Correct answer: B. Tmax
10. Which parameter represents the extent of drug absorption?
- A. Cmax
- B. Tmax
- C. AUC
- D. Clearance
Correct answer: C. AUC
11. What effect does increased gastric emptying have on drug absorption?
- A. Decreases absorption
- B. Enhances rate of absorption
- C. Decreases permeability
- D. Increases metabolism
Correct answer: B. Enhances rate of absorption
12. A drug absorbed through the oral mucosa avoids:
- A. Drug-drug interactions
- B. Enterohepatic recycling
- C. First-pass metabolism
- D. Enzymatic degradation
Correct answer: C. First-pass metabolism
13. Which transporter limits drug absorption in the GI tract?
- A. CYP3A4
- B. P-glycoprotein
- C. SGLT1
- D. MDR2
Correct answer: B. P-glycoprotein
14. In which part of the GI tract is drug absorption least efficient?
- A. Duodenum
- B. Jejunum
- C. Ileum
- D. Stomach
Correct answer: D. Stomach
15. Drugs with high molecular weight are typically absorbed via:
- A. Passive diffusion
- B. Endocytosis
- C. Efflux transport
- D. Osmosis
Correct answer: B. Endocytosis
16. The process by which solid drug particles dissolve in GI fluids is called:
- A. Diffusion
- B. Partitioning
- C. Dissolution
- D. Hydrolysis
Correct answer: C. Dissolution
17. Which of the following is a parenteral route of administration?
- A. Oral
- B. Rectal
- C. Intravenous
- D. Sublingual
Correct answer: C. Intravenous
18. What is the impact of high gastric pH on weakly acidic drugs?
- A. Increases unionized form
- B. Enhances absorption
- C. Increases ionization and reduces absorption
- D. No impact
Correct answer: C. Increases ionization and reduces absorption
19. Drugs designed for controlled release are absorbed:
- A. Only in the stomach
- B. Immediately upon administration
- C. Slowly over an extended period
- D. Only via IV
Correct answer: C. Slowly over an extended period
20. Which formulation has the fastest rate of absorption?
- A. Enteric-coated tablet
- B. Extended-release capsule
- C. Oral suspension
- D. Suppository
Correct answer: C. Oral suspension
21. The term “absorption window” refers to:
- A. Time needed to reach Tmax
- B. Region in GI tract where drug absorption is optimal
- C. Dose range of drug absorption
- D. Tablet disintegration time
Correct answer: B. Region in GI tract where drug absorption is optimal
22. A drug with high first-pass metabolism will have:
- A. Increased absorption
- B. Lower oral bioavailability
- C. Prolonged half-life
- D. Increased renal clearance
Correct answer: B. Lower oral bioavailability
23. Which of the following enhances absorption of lipophilic drugs?
- A. Alkaline environment
- B. Large surface area
- C. Tight junctions
- D. High protein binding
Correct answer: B. Large surface area
24. Buccal and sublingual routes:
- A. Are unsuitable for emergency use
- B. Undergo significant first-pass metabolism
- C. Offer rapid absorption into systemic circulation
- D. Are always slow-acting
Correct answer: C. Offer rapid absorption into systemic circulation
25. Which physiological factor can delay oral drug absorption?
- A. Increased blood flow
- B. Delayed gastric emptying
- C. High surface area
- D. Lipophilic formulation
Correct answer: B. Delayed gastric emptying
26. Which pH environment favors absorption of weak acids?
- A. Neutral
- B. Alkaline
- C. Acidic
- D. Buffered
Correct answer: C. Acidic
27. The main mechanism of drug absorption across enterocytes is:
- A. Active transport
- B. Pinocytosis
- C. Passive diffusion
- D. Bulk flow
Correct answer: C. Passive diffusion
28. What is the impact of GI motility on absorption?
- A. No impact
- B. Increased motility always increases absorption
- C. Altered motility can either enhance or reduce absorption
- D. Only affects hydrophilic drugs
Correct answer: C. Altered motility can either enhance or reduce absorption
29. The process of forming micelles aids in absorption of:
- A. Proteins
- B. Hydrophilic drugs
- C. Lipophilic drugs
- D. Sugars
Correct answer: C. Lipophilic drugs
30. Which dosage form bypasses absorption entirely?
- A. IV injection
- B. Oral capsule
- C. Buccal tablet
- D. Topical cream
Correct answer: A. IV injection
31. What does the term “bioavailability” quantify?
- A. Distribution extent
- B. Metabolism rate
- C. Fraction of administered dose reaching systemic circulation
- D. Renal excretion
Correct answer: C. Fraction of administered dose reaching systemic circulation
32. Which drug property promotes facilitated diffusion?
- A. Lipophilicity
- B. Ionization
- C. Carrier protein affinity
- D. High molecular weight
Correct answer: C. Carrier protein affinity
33. How does efflux transporters affect drug absorption?
- A. Enhance it
- B. Inhibit it
- C. Have no effect
- D. Completely block passive diffusion
Correct answer: B. Inhibit it
34. The rate and extent of absorption is directly affected by:
- A. Molecular polarity
- B. Drug’s chemical name
- C. Brand manufacturer
- D. Temperature of environment
Correct answer: A. Molecular polarity
35. Which of the following drugs would be best absorbed in the stomach?
- A. Weak acids
- B. Weak bases
- C. Neutral drugs
- D. Proteins
Correct answer: A. Weak acids
36. What is the role of bile salts in drug absorption?
- A. Neutralize drug
- B. Break down drug molecules
- C. Solubilize lipophilic drugs
- D. Increase gastric pH
Correct answer: C. Solubilize lipophilic drugs
37. Drugs formulated as nanoparticles tend to show:
- A. Slower onset
- B. Reduced surface area
- C. Enhanced dissolution and absorption
- D. Poor permeability
Correct answer: C. Enhanced dissolution and absorption
38. A drug that is a substrate for P-glycoprotein will likely have:
- A. Higher absorption
- B. Reduced oral bioavailability
- C. Increased tissue penetration
- D. Enhanced renal excretion
Correct answer: B. Reduced oral bioavailability
39. Prodrugs are often designed to:
- A. Enhance appearance
- B. Decrease dissolution
- C. Improve absorption and bioavailability
- D. Reduce potency
Correct answer: C. Improve absorption and bioavailability
40. Enteric-coated formulations are designed to:
- A. Dissolve in the mouth
- B. Protect drug from stomach acid and release in intestine
- C. Enhance stomach absorption
- D. Be taken sublingually
Correct answer: B. Protect drug from stomach acid and release in intestine
41. Drug absorption can be enhanced using:
- A. Coatings that delay disintegration
- B. Surfactants or solubilizing agents
- C. Large crystal formulations
- D. Hydrophobic binders
Correct answer: B. Surfactants or solubilizing agents
42. Sublingual and buccal drug delivery avoids:
- A. Taste alterations
- B. Gastrointestinal irritation
- C. Hepatic first-pass metabolism
- D. Active transport
Correct answer: C. Hepatic first-pass metabolism
43. What is the primary absorption site for most nutrients and drugs?
- A. Colon
- B. Rectum
- C. Small intestine
- D. Esophagus
Correct answer: C. Small intestine
44. Passive diffusion is dependent on:
- A. Protein carriers
- B. Energy supply
- C. Concentration gradient
- D. Genetic expression
Correct answer: C. Concentration gradient
45. Increasing the surface area of a drug:
- A. Slows absorption
- B. Reduces solubility
- C. Enhances dissolution rate
- D. Alters metabolism
Correct answer: C. Enhances dissolution rate
46. Which organ receives most of the absorbed drug from the GI tract first?
- A. Kidney
- B. Lungs
- C. Liver
- D. Heart
Correct answer: C. Liver
47. Gastric pH in neonates is:
- A. More acidic than adults
- B. Similar to adults
- C. Higher (more alkaline) than adults
- D. Does not affect drug absorption
Correct answer: C. Higher (more alkaline) than adults
48. Which route is NOT commonly used to enhance systemic drug absorption?
- A. Transdermal
- B. Intramuscular
- C. Topical (local)
- D. Intranasal
Correct answer: C. Topical (local)
49. A salt form of a drug is primarily used to:
- A. Improve taste
- B. Reduce dosage
- C. Enhance solubility and absorption
- D. Avoid metabolism
Correct answer: C. Enhance solubility and absorption
50. Which characteristic is most important for transdermal absorption?
- A. High polarity
- B. Large molecular weight
- C. Lipophilicity and low dose
- D. Strong protein binding
Correct answer: C. Lipophilicity and low dose