Introduction: Targeted delivery is a cornerstone of modern pharmaceutics, focusing on directing drugs to specific cells, tissues, or organs to improve efficacy and reduce systemic toxicity. Key concepts include active targeting (ligand–receptor interactions), passive targeting (EPR effect), controlled release, biodistribution, pharmacokinetics, nanoparticles, liposomes, antibody–drug conjugates (ADCs), and polymeric carriers. Advantages include increased specificity, dose-sparing, reduced side effects, and improved therapeutic index; disadvantages involve complex manufacturing, immunogenicity, off-target uptake, stability challenges, and regulatory hurdles. This concise overview equips B.Pharm students with essential keywords and concepts. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which term best describes delivery that relies on enhanced permeability and retention in tumors?
- Active targeting
- Passive targeting
- Receptor-mediated targeting
- Site-specific release
Correct Answer: Passive targeting
Q2. Which of the following is an example of an active targeting ligand used on nanocarriers?
- PEG (polyethylene glycol)
- Folate
- PLGA (poly(lactic-co-glycolic acid))
- Sucrose
Correct Answer: Folate
Q3. What is a primary advantage of targeted drug delivery compared to conventional systemic therapy?
- Higher manufacturing cost
- Increased off-target toxicity
- Improved therapeutic index
- Reduced shelf-life
Correct Answer: Improved therapeutic index
Q4. Which carrier is commonly used for both hydrophilic and hydrophobic drugs and can reduce systemic toxicity?
- Liposomes
- Metal salts
- Simple syrup
- Inorganic glass beads
Correct Answer: Liposomes
Q5. Which of the following is a major disadvantage associated with targeted nanoparticles?
- Reduced immunogenicity
- High scalability and low cost
- Complex manufacturing and regulatory challenges
- Guaranteed tissue penetration
Correct Answer: Complex manufacturing and regulatory challenges
Q6. PEGylation of nanoparticles primarily aims to:
- Increase recognition by the reticuloendothelial system
- Decrease circulation time
- Improve stealth properties and prolong circulation
- Promote rapid aggregation
Correct Answer: Improve stealth properties and prolong circulation
Q7. Antibody–drug conjugates (ADCs) mainly provide targeted delivery by:
- Releasing drug through pH-independent diffusion
- Using antibodies to bind specific tumor antigens
- Relying on nonspecific EPR effect only
- Increasing systemic clearance
Correct Answer: Using antibodies to bind specific tumor antigens
Q8. Which factor most influences biodistribution of nanoparticle carriers?
- Color of formulation
- Particle size and surface charge
- Manufacturer location
- Container shape
Correct Answer: Particle size and surface charge
Q9. A disadvantage of ligand-mediated targeting is:
- Universal expression of target receptors
- Potential immunogenicity of targeting ligands
- Lower specificity compared with systemic drugs
- Elimination of off-target effects completely
Correct Answer: Potential immunogenicity of targeting ligands
Q10. Controlled release in targeted delivery systems primarily helps to:
- Instantly spike toxic plasma levels
- Maintain therapeutic concentrations over time
- Prevent any drug–target interactions
- Increase dosing frequency
Correct Answer: Maintain therapeutic concentrations over time
Q11. Which assay is commonly used to evaluate cellular uptake of targeted nanoparticles in vitro?
- UV–visible spectroscopy of bulk drug
- Flow cytometry
- Simple pH paper test
- Taste testing
Correct Answer: Flow cytometry
Q12. The term “therapeutic index” refers to:
- The ratio of toxic dose to therapeutic dose
- The manufacturing cost per dose
- Number of targeting ligands per carrier
- Drug color intensity
Correct Answer: The ratio of toxic dose to therapeutic dose
Q13. Which characteristic of tumors enables passive targeting by nanoparticles?
- Tight endothelial junctions
- Enhanced vascular permeability and poor lymphatic drainage
- Rapid renal clearance of particles
- High density of normal tissue
Correct Answer: Enhanced vascular permeability and poor lymphatic drainage
Q14. Which surface modification can reduce opsonization and uptake by macrophages?
- Surface coating with hydrophobic proteins
- PEGylation
- Increasing positive zeta potential
- Adding free sugars to promote recognition
Correct Answer: PEGylation
Q15. A potential disadvantage of targeted delivery in clinical translation is:
- Simple regulatory pathways
- High batch-to-batch variability and scale-up difficulty
- Guaranteed patient response
- Zero cost of goods
Correct Answer: High batch-to-batch variability and scale-up difficulty
Q16. Which feature improves receptor-mediated endocytosis of targeted carriers?
- Absence of ligand on carrier surface
- Appropriate ligand density and orientation
- Extremely large particle size (>10 μm)
- Highly basic carriers causing denaturation
Correct Answer: Appropriate ligand density and orientation
Q17. Which is a common toxicity concern unique to nano-formulations?
- Enhanced enzymatic digestion in stomach
- Nanoparticle-induced oxidative stress and inflammation
- Reduced API potency only in vitro
- Guaranteed renal excretion without accumulation
Correct Answer: Nanoparticle-induced oxidative stress and inflammation
Q18. Liposomal encapsulation primarily reduces toxicity by:
- Increasing free drug concentration in plasma
- Restricting drug distribution to target or reducing exposure to healthy tissues
- Accelerating metabolic breakdown to inactive forms
- Enhancing taste masking only
Correct Answer: Restricting drug distribution to target or reducing exposure to healthy tissues
Q19. What role does drug release kinetics play in targeted delivery?
- Determines neither efficacy nor safety
- Influences duration of action, local concentration, and side-effect profile
- Only affects color of formulation
- Always leads to immediate drug elimination
Correct Answer: Influences duration of action, local concentration, and side-effect profile
Q20. Which analytical technique is useful for particle size determination of nanocarriers?
- Dynamic light scattering (DLS)
- Thin-layer chromatography without staining
- Basic weight measurement
- Simple visual inspection
Correct Answer: Dynamic light scattering (DLS)
Q21. Which of the following improves tumor penetration of nanocarriers?
- Very large particle size (>500 nm)
- Optimization of size (~50–200 nm) and surface properties
- Strong positive charge causing aggregation
- Absence of any surface modification
Correct Answer: Optimization of size (~50–200 nm) and surface properties
Q22. A key regulatory challenge for targeted delivery systems is:
- Clear, universal standards for all nanomedicines
- Complexity in demonstrating safety, efficacy, and characterization
- No need for clinical trials
- Automatic approval due to novelty
Correct Answer: Complexity in demonstrating safety, efficacy, and characterization
Q23. Which is a benefit of conjugating drugs to antibodies (ADCs) over free drug?
- Increased nonspecific distribution
- Targeted cytotoxic delivery to antigen-expressing cells
- Shorter circulation half-life
- Higher systemic side effects
Correct Answer: Targeted cytotoxic delivery to antigen-expressing cells
Q24. Off-target accumulation of targeted carriers can cause:
- No clinical consequences
- Unintended toxicity in healthy organs
- Guaranteed enhancement of therapeutic effect
- Immediate elimination without effects
Correct Answer: Unintended toxicity in healthy organs
Q25. Which strategy can enhance intracellular drug release once a carrier is endocytosed?
- pH-sensitive linkers that cleave in endosomes
- Using non-cleavable, permanently stable linkers only
- Avoiding any responsive chemistry
- Coating with insoluble metals
Correct Answer: pH-sensitive linkers that cleave in endosomes
Q26. Which is an economic disadvantage of advanced targeted delivery systems?
- Lower R&D costs
- High development and manufacturing costs
- Guaranteed low market price
- No requirement for quality control
Correct Answer: High development and manufacturing costs
Q27. Which physiological barrier is most relevant for delivering drugs to the brain?
- Blood–brain barrier (BBB)
- Gastric mucosal barrier
- Skin stratum corneum only
- Renal glomerular filtration
Correct Answer: Blood–brain barrier (BBB)
Q28. Which modification helps reduce protein corona formation on nanoparticles?
- Adding hydrophobic patches
- Surface functionalization with stealth polymers like PEG
- Increasing roughness to trap proteins
- Coating with sticky sugars
Correct Answer: Surface functionalization with stealth polymers like PEG
Q29. Combining targeted delivery with imaging agents for diagnosis and therapy is called:
- Pharmacovigilance
- Theranostics
- Simple spectroscopy
- Non-specific labeling
Correct Answer: Theranostics
Q30. Which factor is critical to ensure reproducible performance of targeted drug products?
- Ignoring particle characterization
- Robust characterization of size, charge, ligand density, and release profile
- Random variation of formulation parameters
- Absence of stability testing
Correct Answer: Robust characterization of size, charge, ligand density, and release profile

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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