Manufacture of pharmaceutical aerosols MCQs With Answer

Manufacture of pharmaceutical aerosols MCQs With Answer is an essential review for B.Pharm students focusing on aerosol formulation, propellants, filling technology, and device engineering. This concise guide covers formulation components, selection and handling of propellants (CFCs, HFA), pressurized metered-dose inhaler (pMDI) valves and actuators, suspension vs solution aerosols, particle size control, spray pattern, plume geometry, and dose uniformity. It also emphasizes manufacturing steps, quality control tests, stability and compatibility, cleaning and filling operations, safety and environmental regulations, and packaging. Learning these core concepts strengthens understanding of aerosol production, performance, and regulatory expectations. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which property of a propellant is most critical for controlling the vapor pressure and thus dose delivery in a pressurized metered-dose inhaler?

• Molecular weight
• Vapor pressure at formulation temperature
• Boiling point under ambient pressure
• Polarity

Correct Answer: Vapor pressure at formulation temperature

Q2. Which filling method involves charging the canister with the drug formulation first, then adding liquefied propellant afterward under controlled pressure?

• Pressure-fill method
• Cold-fill method
• Passive-fill method
• Hot-fill method

Correct Answer: Cold-fill method

Q3. In suspension aerosols, which excipient is primarily used to improve physical stability by preventing rapid settling of particles?

• Surfactants
• Viscosity modifiers (suspending agents)
• Antioxidants
• Preservatives

Correct Answer: Viscosity modifiers (suspending agents)

Q4. Which device component determines the metered volume of drug formulation released per actuation?

• Actuator orifice geometry
• Canister material
• Metering valve chamber
• Dip tube length

Correct Answer: Metering valve chamber

Q5. What does MMAD stand for and why is it important in aerosol performance?

• Mass Mean Aerodynamic Diameter; indicates particle aerodynamic behavior and deposition site
• Mean Mass Average Diameter; measures chemical stability
• Maximum Median Aeration Diameter; determines spray plume angle
• Mass Median Aerodynamic Diameter; evaluates propellant compatibility

Correct Answer: Mass Median Aerodynamic Diameter; indicates particle aerodynamic behavior and deposition site

Q6. Which analytical technique is the regulatory standard for measuring aerodynamic particle size distribution of inhalation aerosols?

• Laser diffraction
• Cascade impactor
• Dynamic light scattering
• Scanning electron microscopy

Correct Answer: Cascade impactor

Q7. Why are hydrofluoroalkane (HFA) propellants preferred over CFCs in modern pharmaceutical aerosols?

• Higher toxicity but better performance
• Lower cost and easier handling
• Ozone-depletion potential is lower and regulatory acceptance
• Better solubilizing power for all drugs

Correct Answer: Ozone-depletion potential is lower and regulatory acceptance

Q8. Which test assesses uniformity of dose delivered across consecutive actuations from an inhaler?

• Spray pattern test
• Dose content uniformity test
• Valve delivery test (delivered dose uniformity)
• Leak test

Correct Answer: Valve delivery test (delivered dose uniformity)

Q9. In designing aerosol formulations, which factor most directly affects plume geometry and spray pattern?

• Drug chemical structure
• Actuator orifice size and shape
• Canister coating
• Propellant global warming potential

Correct Answer: Actuator orifice size and shape

Q10. Which compatibility concern is most relevant when mixing a corticosteroid suspension with an HFA propellant?

• Oxidative degradation by propellant
• Interaction with valve elastomers and drug adsorption
• Hydrolysis due to moisture
• Photodegradation inside canister

Correct Answer: Interaction with valve elastomers and drug adsorption

Q11. What is the primary purpose of adding a co-solvent (e.g., ethanol) to an HFA solution MDI formulation?

• Increase flammability for sterilization
• Enhance solvent power for the drug and modify plume characteristics
• Reduce manufacturing costs
• Stabilize propellant vapor pressure

Correct Answer: Enhance solvent power for the drug and modify plume characteristics

Q12. During manufacturing, which environmental control is most critical due to flammability risks with HFA-ethanol mixtures?

• Temperature control only
• Humidity control only
• Explosion-proof electrical installations and grounding
• Biological safety cabinets

Correct Answer: Explosion-proof electrical installations and grounding

Q13. Which failure mode is indicated by increased delivered dose variability and formation of large aggregates in suspension MDIs during stability study?

• Chemical degradation of drug
• Particle agglomeration and creaming/sedimentation instability
• Leakage through valve
• Loss of propellant due to permeation

Correct Answer: Particle agglomeration and creaming/sedimentation instability

Q14. What role does valve stem material play in aerosol formulation stability?

• No role; valve stem is inert in all cases
• Controls propellant vapor pressure
• May sorb drug or leach additives, affecting dose uniformity and compatibility
• Determines canister corrosion only

Correct Answer: May sorb drug or leach additives, affecting dose uniformity and compatibility

Q15. Which quality control test evaluates the spray’s spatial distribution and uniformity immediately after actuation?

• Leak test
• Spray pattern and plume geometry test
• Conductivity test
• pH measurement

Correct Answer: Spray pattern and plume geometry test

Q16. In metered-dose inhaler design, reducing the metering chamber volume will primarily affect which attribute?

• Particle aerodynamic diameter
• Delivered dose per actuation
• Propellant global warming potential
• Valve corrosion resistance

Correct Answer: Delivered dose per actuation

Q17. Which process is commonly used to micronize drug particles to achieve respirable particle size for suspension MDIs?

• Freeze-drying
• Jet milling or micronization
• Spray cooling
• Rotary evaporation

Correct Answer: Jet milling or micronization

Q18. What is the main environmental concern associated with earlier CFC propellants that led to their phase-out?

• High flammability
• Ozone layer depletion
• Excessive greenhouse warming
• Formation of particulate emissions

Correct Answer: Ozone layer depletion

Q19. Which parameter measured by a cascade impactor indicates dispersion breadth of the aerosol particle size distribution?

• Mass Median Aerodynamic Diameter (MMAD)
• Geometric Standard Deviation (GSD)
• Delivered dose
• Plume angle

Correct Answer: Geometric Standard Deviation (GSD)

Q20. During aerosol manufacturing, which cleaning validation concern is unique compared to non-pressurized dosage forms?

• Removal of microbiological contaminants only
• Residues in valves, actuators, and filling lines that may interact with propellants
• pH neutralization in aqueous sinks
• Color removal from glassware

Correct Answer: Residues in valves, actuators, and filling lines that may interact with propellants

Q21. What is the primary effect of increasing formulation viscosity in a suspension MDI?

• Faster evaporation of propellant
• Reduced settling rate and altered spray breakup
• Increased chemical degradation
• Higher flammability

Correct Answer: Reduced settling rate and altered spray breakup

Q22. Which regulatory guideline is most relevant for quality control of inhalation aerosols and nebulizers?

• ICH Q5A
• USP chapters related to aerosols and inhalation products
• ICH Q8 only
• European Water Directive

Correct Answer: USP chapters related to aerosols and inhalation products

Q23. For a solution MDI, which formulation attribute is least likely to cause particle agglomeration issues?

• Incomplete solubilization of drug
• Use of a true molecular solution (drug fully dissolved)
• Precipitation upon actuation
• Interaction of drug with valve components

Correct Answer: Use of a true molecular solution (drug fully dissolved)

Q24. What is the purpose of priming an MDI before first use and after prolonged storage?

• To sterilize the actuator
• To ensure correct dose metering and remove any evaporative concentration effects
• To increase propellant pressure permanently
• To clean the mouthpiece

Correct Answer: To ensure correct dose metering and remove any evaporative concentration effects

Q25. Which excipient type is commonly added to suspension MDIs to reduce surface adsorption of drug onto metal or elastomer surfaces?

• Chelating agents
• Surfactants/wetting agents
• Antioxidants
• Buffers

Correct Answer: Surfactants/wetting agents

Q26. In aerosol filling lines, what is a common in-process control to confirm canister integrity after crimping?

• Visual color check
• Leak test (pressure or vacuum decay)
• pH of headspace
• Viscosity measurement

Correct Answer: Leak test (pressure or vacuum decay)

Q27. Which manufacturing challenge is especially important for combination inhalers containing two active drugs in suspension?

• Achieving homogenous chemical reaction between actives
• Ensuring physical compatibility, differential sedimentation, and uniform co-dosing
• Preventing bioburden in canister headspace
• Eliminating all surfactants

Correct Answer: Ensuring physical compatibility, differential sedimentation, and uniform co-dosing

Q28. Which factor most influences lung deposition efficiency for a given aerosol formulation?

• Packaging color
• Patient inhalation flow profile and particle aerodynamic size
• Ambient humidity only
• Canister wall thickness

Correct Answer: Patient inhalation flow profile and particle aerodynamic size

Q29. Which safety measure is critical when performing compatibility testing between drug formulation and valve elastomers?

• Use of non-representative elastomer samples
• Accelerated aging under realistic temperature and pressure conditions with extractables/leachables analysis
• Only performing short-term room temperature contact tests
• Skipping analytical verification if visual inspection is clear

Correct Answer: Accelerated aging under realistic temperature and pressure conditions with extractables/leachables analysis

Q30. What is the principal reason for conducting spray content uniformity (SCU) testing across the life of an inhaler?

• To monitor the canister external appearance
• To ensure each actuation throughout the labeled number of doses delivers consistent API amount
• To measure propellant boiling point
• To check packaging label accuracy

Correct Answer: To ensure each actuation throughout the labeled number of doses delivers consistent API amount

G S Sachin

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.

Mail- Sachin@pharmacyfreak.com