Pulmonary drug delivery systems MCQs With Answer

Introduction: Pulmonary drug delivery systems are essential components of modern therapy for respiratory and systemic diseases. This set of MCQs is designed specifically for M.Pharm students studying Molecular Pharmaceutics / NTDS (MPH 201T) and focuses on principles, device technologies, particle engineering, deposition mechanics, pharmacokinetics, and regulatory/analytical methods related to inhalation therapeutics. These questions go beyond basic definitions to probe understanding of aerodynamic diameter, formulation–device interactions, lung clearance mechanisms, in vitro testing (e.g., cascade impactor), and strategies for targeted or systemic delivery via the lungs. Use them for revision, self-assessment, or classroom quizzes to strengthen critical thinking in pulmonary drug delivery design and evaluation.

Q1. Which of the following is the most significant advantage of pulmonary drug delivery compared with oral administration?

• Lower formulation cost
• Larger dosing volume tolerated
• Rapid systemic absorption and avoidance of first-pass metabolism
• Easier sterilization requirements

Correct Answer: Rapid systemic absorption and avoidance of first-pass metabolism

Q2. In aerosol science, which diameter most accurately predicts particle deposition behavior in the respiratory tract?

• Geometric diameter
• Volume diameter
• Optical diameter
• Mass median aerodynamic diameter (MMAD)

Correct Answer: Mass median aerodynamic diameter (MMAD)

Q3. For effective alveolar deposition of inhaled particles, the optimal aerodynamic diameter range is generally considered to be:

• >10 µm
• 5–10 µm
• 1–5 µm
• <0.1 µm

Correct Answer: 1–5 µm

Q4. Which mechanism predominantly causes deposition of submicron particles (<0.5 µm) in the alveolar region?

• Inertial impaction
• Gravitational sedimentation
• Brownian diffusion
• Electrostatic attraction

Correct Answer: Brownian diffusion

Q5. Which device is breath-actuated and reduces coordination problems between actuation and inhalation?

• Pressurized metered-dose inhaler (pMDI) without spacer
• Dry powder inhaler (DPI) with passive aerosolization
• Jet nebulizer
• Soft mist inhaler with manual actuation

Correct Answer: Dry powder inhaler (DPI) with passive aerosolization

Q6. Which formulation approach is commonly used to improve powder flow and dispersion in DPI formulations?

• Use of high concentration liquid vehicles
• Co-spray drying with large carrier lactose crystals
• Increasing hygroscopicity of particles
• Formulating as nanosuspensions in propellants

Correct Answer: Co-spray drying with large carrier lactose crystals

Q7. Fine particle fraction (FPF) in inhalation aerosols refers to:

• The fraction of particles >10 µm
• The fraction of emitted dose collected in the throat
• The fraction of dose with aerodynamic diameter typically <5 µm
• The fraction retained in the inhaler device

Correct Answer: The fraction of dose with aerodynamic diameter typically <5 µm

Q8. Which in vitro method is the gold standard for aerodynamic characterization of inhalation aerosols?

• Laser diffraction without inhalation simulation
• Next Generation Impactor (NGI) or Andersen Cascade Impactor
• High-performance liquid chromatography (HPLC)
• Dynamic light scattering (DLS)

Correct Answer: Next Generation Impactor (NGI) or Andersen Cascade Impactor

Q9. Hygroscopic growth of particles in the humid lung environment will most likely result in which effect?

• Reduced geometric size but unchanged aerodynamic behavior
• Increased particle size and enhanced deposition by sedimentation
• Complete evaporation of particles before reaching alveoli
• Decreased deposition due to increased electrostatic repulsion

Correct Answer: Increased particle size and enhanced deposition by sedimentation

Q10. Which excipient is commonly used as a carrier in DPI formulations to improve dose uniformity and flow?

• Polyethylene glycol (PEG-400)
• Lactose monohydrate
• Sodium lauryl sulfate
• Benzalkonium chloride

Correct Answer: Lactose monohydrate

Q11. Which statement best describes the role of propellants in pressurized metered-dose inhalers (pMDIs)?

• Propellants dissolve all the drug and act as preservatives
• Propellants generate the aerosol by rapid expansion and atomization of formulation
• Propellants increase drug solubility in the lung lining fluid
• Propellants prevent particle aggregation in nebulizers

Correct Answer: Propellants generate the aerosol by rapid expansion and atomization of formulation

Q12. Which lung clearance mechanism is primarily responsible for removing particles deposited in the tracheobronchial region?

• Alveolar macrophage phagocytosis
• Mucociliary clearance
• Transcytosis across alveolar epithelium
• Renal excretion

Correct Answer: Mucociliary clearance

Q13. When designing particles for deep lung targeting of a biologic, which property is most critical to enhance epithelial uptake and avoid macrophage clearance?

• Large geometric diameter (>10 µm)
• Hydrophobic surface and rigid structure
• Controlled nano-to-microscale size with surface modification (e.g., PEGylation)
• High density metallic cores

Correct Answer: Controlled nano-to-microscale size with surface modification (e.g., PEGylation)

Q14. Which analytical parameter from cascade impactor testing best indicates the central tendency of particle aerodynamic size distribution?

• Fine particle fraction (FPF)
• Mass median aerodynamic diameter (MMAD)
• Geometric standard deviation (GSD)
• Emitted dose

Correct Answer: Mass median aerodynamic diameter (MMAD)

Q15. In nebulizer design, which factor most influences droplet size produced by a jet nebulizer?

• Electrical conductivity of drug solution
• Nozzle geometry and gas flow rate
• Color of the drug solution
• pH above 10 only

Correct Answer: Nozzle geometry and gas flow rate

Q16. Surfactants are sometimes included in inhalation formulations primarily to:

• Promote particle aggregation
• Reduce surface tension and improve aerosol stability
• Increase solution viscosity to prevent nebulization
• Act as strong preservatives for long-term storage

Correct Answer: Reduce surface tension and improve aerosol stability

Q17. Which regulatory or performance attribute is critical for bioequivalence assessment of generic inhalation products?

• Color matching of device casing
• Similarity in in vitro aerodynamic performance (e.g., MMAD, FPF) and device dispersion characteristics
• Identical excipients irrespective of function
• Using the same manufacturing site only

Correct Answer: Similarity in in vitro aerodynamic performance (e.g., MMAD, FPF) and device dispersion characteristics

Q18. For systemic delivery of peptides via the pulmonary route, which strategy can improve bioavailability?

• Formulating as highly charged large crystals
• Use of absorption/permeation enhancers and enzyme inhibitors
• Increasing mucociliary clearance rate deliberately
• Administering with large lactose carrier crystals only

Correct Answer: Use of absorption/permeation enhancers and enzyme inhibitors

Q19. Which statement about spray-drying for inhalation powders is correct?

• Spray-drying always produces non-porous, dense particles
• Spray-drying conditions can be tuned to produce porous low-density particles with favorable aerodynamic properties
• Spray-drying is unsuitable for biologics due to heat exposure in all cases
• Spray-drying eliminates the need for downstream particle engineering

Correct Answer: Spray-drying conditions can be tuned to produce porous low-density particles with favorable aerodynamic properties

Q20. Which in vivo factor most complicates translation of in vitro aerosol data to human pulmonary deposition predictions?

• Uniform airway geometry across all patients
• Inter-individual variability in inhalation flow profile, airway anatomy, and disease state
• Constant ambient humidity and temperature
• Standardized breathing maneuvers in all subjects

Correct Answer: Inter-individual variability in inhalation flow profile, airway anatomy, and disease state

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