Formulation and evaluation of nasal sprays and nebulizers are essential topics for B. Pharm students focusing on drug delivery, aerosol science, and respiratory therapeutics. This guide covers formulation aspects (solutions, suspensions, preservatives, tonicity agents, mucoadhesives), device selection (jet, ultrasonic, mesh nebulizers; pump nasal sprays), and critical evaluation parameters including particle/droplet size, MMAD, geometric standard deviation, spray pattern, plume geometry, sterility, and stability testing. Understanding excipient compatibility, device–formulation interaction, and in vitro tests (cascade impactor, laser diffraction, aerosol output, delivered dose uniformity) builds practical skills for formulation development and quality control. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which mass median aerodynamic diameter (MMAD) range is generally optimal for deep lung deposition with nebulized aerosols?
- 10–50 µm
- 5–10 µm
- 1–5 µm
- 50–100 µm
Correct Answer: 1–5 µm
Q2. Which of the following is NOT a common type of nebulizer?
- Jet nebulizer
- Ultrasonic nebulizer
- Mesh nebulizer
- Piston pump nebulizer
Correct Answer: Piston pump nebulizer
Q3. What is the primary role of preservatives in multi-dose nasal sprays?
- Increase viscosity for better spray pattern
- Enhance drug absorption through mucosa
- Prevent microbial contamination during use
- Reduce surface tension to form smaller droplets
Correct Answer: Prevent microbial contamination during use
Q4. Which preservative is most commonly used in nasal spray formulations?
- Chlorhexidine gluconate
- Benzalkonium chloride
- Sodium benzoate
- Methylparaben only
Correct Answer: Benzalkonium chloride
Q5. For isotonic nasal formulations, which excipient is commonly employed to adjust tonicity?
- Sodium chloride
- Polyethylene glycol 400
- Polysorbate 80
- Carmellose sodium
Correct Answer: Sodium chloride
Q6. What pH range is generally well tolerated by the nasal mucosa for topical nasal sprays?
- 2.0–3.5
- 4.5–6.5
- 7.5–9.0
- 10–11
Correct Answer: 4.5–6.5
Q7. Which analytical technique is commonly used to measure aerodynamic particle size distribution for inhalation aerosols?
- High-performance liquid chromatography (HPLC)
- Cascade impactor (e.g., NGI)
- Differential scanning calorimetry (DSC)
- Ultraviolet-visible spectroscopy (UV-Vis)
Correct Answer: Cascade impactor (e.g., NGI)
Q8. Which nebulizer parameter describes the amount of drug solution output per unit time?
- Residual volume
- Nebulization rate (output rate)
- Geometric standard deviation
- Spray pattern
Correct Answer: Nebulization rate (output rate)
Q9. Which excipient is commonly used to increase viscosity and prolong nasal residence time?
- Polysorbate 20
- Methylcellulose
- Sodium chloride
- Citric acid
Correct Answer: Methylcellulose
Q10. Which mucoadhesive polymer is known to enhance nasal absorption and retention?
- Chitosan
- Propylene glycol
- Poloxamer 188
- Ethyl alcohol
Correct Answer: Chitosan
Q11. Why is priming a spray pump important before initial use of a nasal spray?
- To sterilize the nozzle
- To activate the preservative system
- To ensure correct dose and consistent spray formation
- To change the droplet size to submicron
Correct Answer: To ensure correct dose and consistent spray formation
Q12. Which nebulizer type is most suitable for heat-sensitive biologics due to low thermal stress?
- Ultrasonic nebulizer
- Jet nebulizer
- Vibrating mesh nebulizer
- Thermal vaporizer nebulizer
Correct Answer: Vibrating mesh nebulizer
Q13. Spray pattern and plume geometry primarily influence which aspect of nasal spray performance?
- Chemical stability of the drug
- Site and distribution of deposition in the nasal cavity
- Microbial preservative effectiveness
- Color of the spray plume
Correct Answer: Site and distribution of deposition in the nasal cavity
Q14. The preservative efficacy test (PET) or antimicrobial effectiveness test (AET) assesses what property of a nasal formulation?
- Particle size distribution
- Ability to resist microbial growth over time
- Viscosity changes under stress
- Delivered dose uniformity
Correct Answer: Ability to resist microbial growth over time
Q15. Which test evaluates dose uniformity for metered-dose nasal pumps?
- pH determination
- Spray viscosity test
- Delivered dose per actuation (content per actuation) test
- Thermal degradation test
Correct Answer: Delivered dose per actuation (content per actuation) test
Q16. What does a high geometric standard deviation (GSD) in aerosol measurements indicate?
- Narrow particle size distribution
- Wide or polydisperse particle size distribution
- High chemical potency
- High solution viscosity
Correct Answer: Wide or polydisperse particle size distribution
Q17. Which factor most strongly affects lung deposition efficiency of nebulized drugs?
- Color of the formulation
- Droplet/aerosol particle size
- Manufacturer’s country
- Container label design
Correct Answer: Droplet/aerosol particle size
Q18. For patient comfort and minimal irritation, nasal sprays are typically formulated to be:
- Hypertonic
- Hypotonic
- Isotonic
- Strongly alkaline
Correct Answer: Isotonic
Q19. Which excipient class is used to lower surface tension and help form uniform droplets in nasal sprays?
- Surfactants (e.g., polysorbate 80)
- Bulking agents (e.g., lactose)
- Preservatives (e.g., benzalkonium chloride)
- Colorants
Correct Answer: Surfactants (e.g., polysorbate 80)
Q20. Which of the following factors has the least impact on aerosol generation and deposition?
- Formulation viscosity
- Device design and nozzle geometry
- Ambient temperature within normal ranges
- Formulation color
Correct Answer: Formulation color
Q21. A common compatibility issue with benzalkonium chloride as a preservative is:
- Interaction and reduced efficacy in presence of high organic load or anionic excipients
- Instability at low pH only
- Formation of explosive peroxides
- Conversion to a gas at room temperature
Correct Answer: Interaction and reduced efficacy in presence of high organic load or anionic excipients
Q22. NGI in inhalation testing stands for:
- National Generic Indicator
- Next Generation Impactor
- Neutral Gas Injector
- Nasal Gyroscopic Instrument
Correct Answer: Next Generation Impactor
Q23. In nebulizer terminology, what does “residual volume” refer to?
- Total volume nebulized per minute
- Volume of drug solution remaining in the nebulizer after nebulization
- Maximum fill volume recommended by manufacturer
- Evaporated volume during nebulization
Correct Answer: Volume of drug solution remaining in the nebulizer after nebulization
Q24. Which nebulizer type usually produces the smallest droplet sizes suitable for lower airway delivery?
- Large-volume jet nebulizer
- Vibrating mesh nebulizer
- Hand spray pump
- Pressurized metered-dose inhaler (pMDI)
Correct Answer: Vibrating mesh nebulizer
Q25. One major advantage of nasal delivery compared with oral dosing is:
- Complete avoidance of mucociliary clearance
- Ability to bypass first-pass hepatic metabolism for rapid systemic absorption
- Guaranteed delivery to the lower lung
- Elimination of need for formulation testing
Correct Answer: Ability to bypass first-pass hepatic metabolism for rapid systemic absorption
Q26. Which in vitro method is frequently used to measure droplet size distribution of sprayed nasal formulations?
- Laser diffraction
- pH meter
- Gas chromatography
- Flame photometry
Correct Answer: Laser diffraction
Q27. To ensure sterility of a sterile nebulizer solution, which terminal step is commonly used when formulation is heat-sensitive?
- Autoclaving at 121°C
- Gamma irradiation only
- Sterile filtration through a 0.22 µm membrane
- Dry heat at 200°C
Correct Answer: Sterile filtration through a 0.22 µm membrane
Q28. Why might a suspension be chosen for a nasal spray formulation?
- To allow rapid chemical degradation of the drug
- To deliver poorly soluble drugs by dispersing solid particles
- To avoid the need for preservatives
- To ensure the formulation is hypertonic
Correct Answer: To deliver poorly soluble drugs by dispersing solid particles
Q29. What does a cascade impactor measure in aerosol characterization?
- Chemical purity of the active pharmaceutical ingredient
- Aerodynamic particle size distribution (APSD)
- Surface tension of the formulation
- Thermal stability of excipients
Correct Answer: Aerodynamic particle size distribution (APSD)
Q30. Which accelerated stability condition is commonly used in ICH studies for evaluating nasal spray stability?
- 5°C/ambient RH
- 25°C/60% RH
- 40°C/75% RH
- 100°C/0% RH
Correct Answer: 40°C/75% RH
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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