Concepts of targeted drug delivery MCQs With Answer

Concepts of Targeted Drug Delivery MCQs With Answer (M.Pharm – Molecular Pharmaceutics/NTDS)

Targeted drug delivery (TDD) aims to concentrate therapeutics at diseased sites while minimizing systemic exposure, thereby improving efficacy and safety. For M.Pharm students in Molecular Pharmaceutics/NTDS (MPH 201T), a solid grasp of passive and active targeting, nanocarrier platforms, ligand–receptor biology, and stimuli-responsive release is essential. This quiz explores the EPR effect, PEGylation, antibody–drug conjugates, organelle targeting, linker chemistry, pharmacokinetics, and translational hurdles such as immunogenicity and heterogeneity of delivery. Each MCQ is designed to probe conceptual depth and practical nuances—from choosing optimal particle size to engineering linkers for controlled release—helping you integrate design principles with clinical realities in advanced drug delivery.

Q1. The primary objective of targeted drug delivery systems is to

• Increase the drug’s aqueous solubility irrespective of site selectivity
• Maximize drug concentration at the disease site while reducing off-target exposure
• Accelerate systemic clearance to avoid toxicity
• Bypass hepatic metabolism completely

Correct Answer: Maximize drug concentration at the disease site while reducing off-target exposure

Q2. Passive targeting of nanocarriers to solid tumors is predominantly attributed to

• Receptor-mediated transcytosis
• Enhanced permeability and retention (EPR) effect
• Efflux pump inhibition
• P-glycoprotein saturation

Correct Answer: Enhanced permeability and retention (EPR) effect

Q3. PEGylation of nanoparticles is primarily employed to

• Increase receptor affinity through multivalent interactions
• Reduce opsonization and RES uptake to prolong circulation
• Enhance endosomal escape by membrane disruption
• Improve mucosal adhesion via cationic charge

Correct Answer: Reduce opsonization and RES uptake to prolong circulation

Q4. In active targeting, ligand-functionalized carriers most commonly enhance uptake via

• Simple diffusion across the plasma membrane
• Receptor-mediated endocytosis
• Paracellular transport through tight junctions
• Direct nuclear pore translocation

Correct Answer: Receptor-mediated endocytosis

Q5. Which acid-labile linker is widely used to enable drug release in endosomal/lysosomal pH?

• Hydrazone linker
• Disulfide linker
• Valine–citrulline peptide linker
• Thioether linker

Correct Answer: Hydrazone linker

Q6. A well-established strategy for hepatocyte targeting exploits which receptor–ligand pair?

• Transferrin receptor – transferrin
• Asialoglycoprotein receptor – N-acetylgalactosamine (GalNAc)
• Folate receptor – folic acid
• Integrin αvβ3 – RGD peptide

Correct Answer: Asialoglycoprotein receptor – N-acetylgalactosamine (GalNAc)

Q7. The essential components of an antibody–drug conjugate (ADC) include

• Antibody, linker, and cytotoxic payload
• Polymer core, surfactant shell, and targeting ligand
• Lipid bilayer, cholesterol, and PEG
• Dendrimer scaffold, spacer arms, and fluorescent tag

Correct Answer: Antibody, linker, and cytotoxic payload

Q8. Which statement about non-cleavable ADC linkers is TRUE?

• They release the free payload in plasma
• They rely on lysosomal degradation to release an amino acid–payload adduct
• They are designed to be redox-sensitive to cytosolic glutathione
• They are preferentially cleaved by cathepsin B

Correct Answer: They rely on lysosomal degradation to release an amino acid–payload adduct

Q9. Doxil (liposomal doxorubicin) exemplifies which targeting strategy?

• Active targeting via folate receptor binding
• Passive targeting through PEGylated long-circulating liposomes
• Magnetic targeting with superparamagnetic cores
• Enzyme-triggered release via cathepsin-cleavable linkers

Correct Answer: Passive targeting through PEGylated long-circulating liposomes

Q10. To exploit EPR while avoiding rapid renal filtration and splenic sequestration, an optimal hydrodynamic size for systemic nanoparticles is typically

• 2–5 nm
• 20–40 nm
• 50–150 nm
• 400–800 nm

Correct Answer: 50–150 nm

Q11. Which intervention can transiently enhance tumor vascular permeability and improve nanoparticle extravasation?

• Focused ultrasound with circulating microbubbles
• High-dose corticosteroids
• Strong vasoconstrictors (e.g., phenylephrine)
• Alkalinization of the tumor microenvironment

Correct Answer: Focused ultrasound with circulating microbubbles

Q12. A commonly used chemical motif for mitochondria-targeted delivery is

• Triphenylphosphonium (TPP) cation
• Arg–Gly–Asp (RGD) peptide
• Transferrin protein
• Polyethyleneimine (PEI)

Correct Answer: Triphenylphosphonium (TPP) cation

Q13. For ligand-decorated nanoparticles, which design parameter most strongly enhances avidity and cellular uptake?

• Surface zeta potential only
• Ligand surface density (multivalency)
• Polymer polydispersity index
• Core crystallinity

Correct Answer: Ligand surface density (multivalency)

Q14. The peptide motif widely used to target αvβ3 integrins on tumor vasculature is

• RGD
• NLS
• CPP (TAT)
• RKR

Correct Answer: RGD

Q15. For noninvasive delivery across the blood–brain barrier, a frequently targeted receptor is

• Low-density lipoprotein receptor-related protein 1 (LRP1)
• Transferrin receptor (TfR)
• Asialoglycoprotein receptor (ASGPR)
• Folate receptor-α

Correct Answer: Transferrin receptor (TfR)

Q16. Repeated dosing of PEGylated liposomes may lead to which phenomenon, reducing their circulation time?

• Enhanced permeability and retention
• Accelerated blood clearance (ABC) phenomenon
• Receptor desensitization
• First-pass elimination

Correct Answer: Accelerated blood clearance (ABC) phenomenon

Q17. A protease-cleavable linker commonly used in ADCs for intracellular activation by cathepsin B is

• Valine–citrulline dipeptide linker
• Disulfide linker
• Hydrazone linker
• Thioether (maleimidomethyl cyclohexane) linker

Correct Answer: Valine–citrulline dipeptide linker

Q18. The principal advantage of magnetic targeting using superparamagnetic nanoparticles is

• Enhanced receptor affinity via multivalency
• Externally guided localization to a specific site using a magnetic field
• Acid-triggered endosomal escape
• Irreversible inhibition of efflux pumps

Correct Answer: Externally guided localization to a specific site using a magnetic field

Q19. Compared to free drug, a successful long-circulating targeted nanocarrier typically shows

• Increased clearance and reduced area under the curve (AUC)
• Decreased half-life with higher volume of distribution
• Prolonged circulation half-life and increased AUC
• Unchanged pharmacokinetic parameters

Correct Answer: Prolonged circulation half-life and increased AUC

Q20. A notable safety concern uniquely amplified by highly cationic nanoparticles is

• Membrane destabilization leading to hemolysis and cytotoxicity
• Reduced interaction with serum proteins
• Impaired endosomal trafficking
• Complete evasion of immune surveillance

Correct Answer: Membrane destabilization leading to hemolysis and cytotoxicity

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