MCQ on Drug Delivery Systems and Bioavailability

🟢 Easy Level (1–20)

1. Which route of administration provides 100% bioavailability?
   a) Intravenous ✔️
   b) Oral
   c) Sublingual
   d) Rectal
   Explanation: IV administration bypasses absorption barriers.
2. The process by which a drug enters the systemic circulation is:
   a) Elimination
   b) Absorption ✔️
   c) Distribution
   d) Metabolism
   Explanation: Absorption involves drug entry from the site of administration.
3. Which of the following is a controlled drug delivery system?
   a) Transdermal patch ✔️
   b) Oral solution
   c) Suppository
   d) Tablet
   Explanation: Transdermal patches provide sustained drug release.
4. The term “bioavailability” refers to:
   a) Elimination rate
   b) Volume of distribution
   c) Fraction of unchanged drug reaching systemic circulation ✔️
   d) Half-life
   Explanation: It measures the extent of drug absorption.
5. Which of the following bypasses first-pass metabolism?
   a) Oral
   b) Sublingual ✔️
   c) Rectal
   d) Buccal
   Explanation: Sublingual route avoids liver metabolism initially.
6. A drug delivery system that releases drug slowly over time is:
   a) Immediate-release
   b) Sustained-release ✔️
   c) Fast-dissolving
   d) Modified binder
   Explanation: Sustained-release systems prolong drug action.
7. Transdermal drug delivery involves:
   a) Nasal route
   b) Oral cavity
   c) Skin ✔️
   d) Rectum
   Explanation: Transdermal systems deliver drugs through skin layers.
8. What is the primary barrier in oral drug absorption?
   a) Stomach pH
   b) Intestinal epithelium ✔️
   c) Blood
   d) Liver
   Explanation: The epithelium regulates passage into bloodstream.
9. Liposomes are used in drug delivery for:
   a) IV fluids
   b) Flavor masking
   c) Targeted delivery ✔️
   d) Capsule binding
   Explanation: Liposomes encapsulate drugs and target tissues.
10. The time to reach maximum concentration in blood is:
    a) AUC
    b) Clearance
    c) Tmax ✔️
    d) Cmin
    Explanation: Tmax indicates absorption rate of a drug.
11. Buccal drug delivery is through:
    a) Cheek mucosa ✔️
    b) Nasal cavity
    c) Lungs
    d) Intestines
    Explanation: Buccal administration delivers via cheek lining.
12. Which dosage form provides zero-order drug release?
    a) Solution
    b) Transdermal patch ✔️
    c) Syrup
    d) Capsule
    Explanation: Zero-order release maintains constant drug levels.
13. Which factor affects oral drug bioavailability?
    a) Molecular color
    b) First-pass metabolism ✔️
    c) Shape
    d) Odor
    Explanation: Liver metabolism reduces active drug reaching circulation.
14. Which delivery route is most affected by food?
    a) Oral ✔️
    b) IV
    c) IM
    d) Subcutaneous
    Explanation: Food can delay or alter GI drug absorption.
15. The abbreviation AUC stands for:
    a) Average usage count
    b) Area Under Curve ✔️
    c) Administration unit
    d) Automatic unit circulation
    Explanation: AUC represents the extent of drug exposure.
16. What is the main component of a transdermal patch?
    a) Binder
    b) Diluent
    c) Polymer matrix ✔️
    d) Lubricant
    Explanation: The matrix controls drug release through skin.
17. Which organ is mainly responsible for first-pass metabolism?
    a) Kidney
    b) Liver ✔️
    c) Heart
    d) Lungs
    Explanation: The liver metabolizes drugs absorbed from the GI tract.
18. In oral drug delivery, solubility is essential for:
    a) Dissolution and absorption ✔️
    b) Injection
    c) Sedimentation
    d) Taste
    Explanation: Poor solubility leads to poor bioavailability.
19. Which type of drug is best suited for transdermal delivery?
    a) Large peptide
    b) Lipophilic drug ✔️
    c) Ionic compounds
    d) High molecular weight
    Explanation: Lipophilic drugs penetrate skin more easily.
20. Enteric-coated tablets dissolve in the:
    a) Stomach
    b) Mouth
    c) Intestine ✔️
    d) Esophagus
    Explanation: Coating protects drug from stomach acid.

🟡 Moderate Level (21–40)

21. Bioequivalence studies compare:
    a) Routes of administration
    b) Two formulations of the same drug ✔️
    c) Two diseases
    d) Two species
    Explanation: They assess whether formulations produce similar effects.
22. The rate-limiting step in oral drug absorption is often:
    a) Distribution
    b) Dissolution ✔️
    c) Elimination
    d) Injection
    Explanation: Poorly soluble drugs dissolve slowly.
23. Micelles are used to improve:
    a) Color
    b) Texture
    c) Solubility of poorly soluble drugs ✔️
    d) Taste
    Explanation: Micelles increase drug solubility in aqueous media.
24. Nanoparticles in drug delivery help in:
    a) Decreasing cost
    b) Targeted delivery and controlled release ✔️
    c) Increasing viscosity
    d) Color enhancement
    Explanation: Nanocarriers can improve tissue targeting.
25. Drug bioavailability is measured using:
    a) Color chart
    b) Plasma concentration-time curve ✔️
    c) Urine color
    d) Scent marker
    Explanation: Plasma levels indicate how much drug is absorbed.
26. Which route avoids absorption phase?
    a) Oral
    b) Rectal
    c) Intravenous ✔️
    d) Transdermal
    Explanation: IV delivers directly to circulation.
27. A major disadvantage of oral route is:
    a) High cost
    b) Pain
    c) First-pass metabolism ✔️
    d) Requires trained personnel
    Explanation: Some drugs lose potency via liver metabolism.
28. Gastroretentive drug delivery targets:
    a) Colon
    b) Rectum
    c) Stomach ✔️
    d) Lungs
    Explanation: Formulations are retained in the stomach for local or systemic action.
29. Which parameter indicates drug absorption rate?
    a) AUC
    b) Tmax ✔️
    c) Vd
    d) Clearance
    Explanation: Lower Tmax implies faster absorption.
30. The initial concentration after IV administration is:
    a) Cmax ✔️
    b) AUC
    c) Half-life
    d) Tmax
    Explanation: Cmax occurs immediately after IV dosing.
31. Osmotic pump tablets use:
    a) Diffusion coating
    b) Osmotic pressure for drug release ✔️
    c) Alcohol
    d) Flavors
    Explanation: They rely on osmotic gradients.
32. Buccal patches are designed for:
    a) GI delivery
    b) Mucosal absorption ✔️
    c) Skin hydration
    d) Eye drug delivery
    Explanation: Placed in the cheek for mucosal uptake.
33. Bioavailability of IV drugs is always:
    a) 50%
    b) 100% ✔️
    c) 80%
    d) 0%
    Explanation: IV bypasses absorption.
34. Prodrugs are used to:
    a) Reduce bioavailability
    b) Improve solubility or absorption ✔️
    c) Increase taste
    d) Reduce metabolism
    Explanation: They are activated post-absorption.
35. Rectal drug delivery avoids:
    a) Colon absorption
    b) IV route
    c) Complete first-pass metabolism ✔️
    d) Skin absorption
    Explanation: Partial avoidance of liver.
36. Controlled release dosage forms release drug:
    a) Instantly
    b) In pulses
    c) At a constant rate ✔️
    d) Unpredictably
    Explanation: Maintains steady plasma levels.
37. What affects drug bioavailability in oral form?
    a) Body weight only
    b) pH, enzymes, food ✔️
    c) Height
    d) Light exposure
    Explanation: GI environment impacts absorption.
38. Fast-dissolving tablets are absorbed:
    a) Through skin
    b) In oral cavity ✔️
    c) Through rectum
    d) In lungs
    Explanation: These disintegrate quickly in mouth.
39. AUC is proportional to:
    a) Color
    b) Onset time
    c) Total drug absorbed ✔️
    d) Drug weight
    Explanation: AUC reflects systemic exposure.
40. The half-life of a drug affects:
    a) Dosing interval ✔️
    b) Bioavailability
    c) Solubility
    d) Odor
    Explanation: Determines how frequently doses are needed.

🔴 Hard Level (41–50)

41. Which delivery system targets drug to specific organs?
    a) Immediate release
    b) Targeted drug delivery ✔️
    c) Effervescent tablets
    d) IR transdermal
    Explanation: Targets reduce systemic exposure.
42. Lipid-based carriers are ideal for:
    a) Lipophilic drugs ✔️
    b) Ionic drugs
    c) Proteins
    d) Antibodies
    Explanation: Enhance solubility and transport.
43. Which carrier system can cross the blood-brain barrier?
    a) Capsules
    b) Nanoparticles ✔️
    c) Liquids
    d) Gels
    Explanation: Nanocarriers can be engineered for BBB penetration.
44. Zero-order release is defined as:
    a) Time-dependent
    b) Constant release rate ✔️
    c) Burst release
    d) Dose-dumping
    Explanation: Ensures stable plasma levels.
45. SNEDDS stands for:
    a) Soluble Neutral Drug Delivery
    b) Self-Nano Emulsifying Drug Delivery System ✔️
    c) Soft Nanoscale Drug Device
    d) Sodium Neutralizing DDS
    Explanation: Promotes emulsification in GI fluids.
46. Mucoadhesive delivery systems adhere to:
    a) Mucosal surfaces ✔️
    b) Liver cells
    c) Blood
    d) Epidermis
    Explanation: For prolonged drug contact with mucosa.
47. The first-pass effect reduces:
    a) Half-life
    b) Cmax
    c) Bioavailability ✔️
    d) Clearance
    Explanation: Hepatic metabolism inactivates some portion.
48. A drug with high first-pass metabolism should be given:
    a) Orally
    b) Sublingually or parenterally ✔️
    c) Topically
    d) Vaginally
    Explanation: Avoids liver initially.
49. Bioequivalence studies must demonstrate:
    a) Same route
    b) Similar AUC and Cmax ✔️
    c) Same brand name
    d) Cheaper cost
    Explanation: Similar exposure means equivalent effects.
50. Pulsatile drug delivery is used for:
    a) Continuous release
    b) Tonic drugs
    c) Circadian rhythm-based therapy ✔️
    d) Water-insoluble drugs
    Explanation: Releases drugs at pre-set intervals.