Coating equipment MCQs With Answer is an essential review for B.Pharm students focusing on tablet coating technology, process control, and equipment selection. This introduction covers key topics including pan coaters, perforated drum coaters, fluidized bed coaters, Wurster systems, spray guns, nozzles, atomization, spray rate, drying air, polymeric film coating, enteric coating, pigments, plasticizers, and troubleshooting common defects. Emphasis is placed on process parameters, scale-up challenges, in-process controls, and quality-by-design (QbD) principles relevant to pharmaceutical manufacturing. These concise, keyword-rich MCQs will reinforce practical knowledge and exam preparation. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which coating equipment is best suited for high-volume tablet film coating with efficient drying and uniformity?
- Conventional pan coater
- Perforated drum coater
- Wurster fluidized bed coater
- Dip coating machine
Correct Answer: Perforated drum coater
Q2. In a film coating process, which parameter mainly controls droplet size from a spray nozzle?
- Coating solution viscosity
- Atomization air pressure
- Coating pan speed
- Exhaust air temperature
Correct Answer: Atomization air pressure
Q3. Which polymer is commonly used for enteric coating to prevent drug release in the stomach?
- Hydroxypropyl methylcellulose (HPMC)
- Ethylcellulose
- Polyvinyl alcohol (PVA)
- Cellulose acetate phthalate (CAP)
Correct Answer: Cellulose acetate phthalate (CAP)
Q4. What is the primary function of a plasticizer in coating formulations?
- Improve colour intensity
- Decrease polymer glass transition temperature and increase flexibility
- Increase coating viscosity
- Act as a preservative
Correct Answer: Decrease polymer glass transition temperature and increase flexibility
Q5. Which coating defect is characterized by flaky coating removal in localized areas exposing the core?
- Pitting
- Twinning
- Peeling
- Orange peel
Correct Answer: Peeling
Q6. In a fluidized bed coater (Wurster), what is the role of the insert tube?
- To reduce airflow
- To concentrate upward air and create a coating zone for particle suspension
- To act as an exhaust manifold
- To spray coating onto a stationary bed
Correct Answer: To concentrate upward air and create a coating zone for particle suspension
Q7. Which in-process control is most critical to monitor during spray coating to avoid overwetting?
- Tablet hardness
- Spray rate and spray-to-dry ratio
- API assay
- Tablet friability
Correct Answer: Spray rate and spray-to-dry ratio
Q8. What effect does increasing inlet air temperature generally have on the coating process?
- Increases drying rate and may reduce tackiness
- Decreases polymer adherence
- Always causes tablet disintegration
- Reduces atomization efficiency
Correct Answer: Increases drying rate and may reduce tackiness
Q9. Which solvent system is preferred for aqueous film coating to reduce flammability and environmental hazards?
- Hydrocarbon solvent
- Aqueous (water-based) coating dispersion
- Alcohol-based organic solvent
- Chlorinated solvent
Correct Answer: Aqueous (water-based) coating dispersion
Q10. What is ‘weight gain’ in the context of tablet coating?
- Increase in tablet diameter after compression
- Percent increase in tablet mass due to coating application
- Loss of moisture from core during coating
- Increase in tablet hardness post-coating
Correct Answer: Percent increase in tablet mass due to coating application
Q11. Which coating parameter is most closely linked to the risk of tablet erosion during coating?
- High atomization pressure
- Excessive spray rate causing overwetting
- Low pan speed
- Using hydrophobic polymers
Correct Answer: Excessive spray rate causing overwetting
Q12. Which measurement technique is used as a PAT tool to monitor coating thickness in real time?
- Thermogravimetric analysis
- NIR spectroscopy
- HPLC assay
- SEM imaging
Correct Answer: NIR spectroscopy
Q13. Which nozzle type is commonly used for fine atomization in pharmaceutical coating?
- Hollow-cone nozzle
- Flat-fan nozzle
- Brush applicator
- Drip dispenser
Correct Answer: Hollow-cone nozzle
Q14. For scale-up of pan coating, which parameter should be maintained to preserve droplet drying behavior?
- Coating colorant concentration
- Spray-to-bed ratio and droplet size distribution
- Tablet core thickness only
- Type of plasticizer only
Correct Answer: Spray-to-bed ratio and droplet size distribution
Q15. Which polymer provides moisture barrier and is commonly used for sustained-release coatings?
- Hydroxypropyl methylcellulose (HPMC)
- Ethylcellulose
- Polyethylene glycol (PEG)
- Polyvinylpyrrolidone (PVP)
Correct Answer: Ethylcellulose
Q16. What is the likely cause of ‘orange peel’ texture on a film-coated tablet?
- Excessive plasticizer
- Poor atomization and high coating viscosity
- Too low inlet air temperature
- Overly smooth tablet cores
Correct Answer: Poor atomization and high coating viscosity
Q17. Which test assesses adhesion strength between coating and tablet core?
- Friability test
- Peel test or adhesion test
- Disintegration test
- Dissolution rate test
Correct Answer: Peel test or adhesion test
Q18. During coating, what is the purpose of exhaust air control?
- To increase spray pressure
- To balance drying rate by removing solvent-laden air
- To cool the coating solution
- To add more humidity to the chamber
Correct Answer: To balance drying rate by removing solvent-laden air
Q19. Which coating defect is indicated by localized white or light spots due to uneven pigment distribution?
- Pitting
- Blooming
- Blistering
- Pigmentation speckling (mottling)
Correct Answer: Pigmentation speckling (mottling)
Q20. What does the term ‘coating efficiency’ typically refer to?
- Percentage of coating solution solids deposited on tablets versus lost as overspray
- Electrical efficiency of the coating motor
- Time taken to complete coating cycle
- Color uniformity score
Correct Answer: Percentage of coating solution solids deposited on tablets versus lost as overspray
Q21. Which analytical method is used to evaluate film coating morphology and thickness after coating?
- Light microscopy or SEM cross-sectioning
- UV spectroscopy
- Gas chromatography
- pH meter
Correct Answer: Light microscopy or SEM cross-sectioning
Q22. Why are surfactants added to coating formulations?
- To act as primary binders
- To reduce surface tension and improve wetting of tablets
- To increase solid content dramatically
- To raise the glass transition temperature
Correct Answer: To reduce surface tension and improve wetting of tablets
Q23. Which condition can promote blistering of the coating film?
- Too slow drying allowing strong film formation
- Rapid evaporation of solvent leading to trapped gases under film
- Use of aqueous dispersions only
- Low spray rate with low inlet temperature
Correct Answer: Rapid evaporation of solvent leading to trapped gases under film
Q24. What is a critical advantage of perforated pan coaters over conventional pans?
- Lower initial cost
- Enhanced drying due to airflow through the bed for faster cycles
- No need for atomization
- They do not require exhaust systems
Correct Answer: Enhanced drying due to airflow through the bed for faster cycles
Q25. Which parameter is adjusted to change residence time of tablets in a coating pan?
- Spray nozzle type
- Pan speed and baffle design
- Coating solution pH
- Tablet hardness
Correct Answer: Pan speed and baffle design
Q26. Which excipient is commonly used as a pore former in sustained-release coatings to control drug release?
- Sorbitol
- Hydroxypropyl cellulose (HPC)
- Magnesium stearate
- Acetone
Correct Answer: Hydroxypropyl cellulose (HPC)
Q27. During coating validation, what is typically monitored to demonstrate consistency across batches?
- Only coating color
- Weight gain, dissolution profile, content uniformity and visual uniformity
- Only tablet hardness
- Room lighting conditions
Correct Answer: Weight gain, dissolution profile, content uniformity and visual uniformity
Q28. Which practice reduces the risk of API migration into the coating layer?
- Use of volatile organic solvents only
- Optimization of coating formulation and drying to limit mobility of API
- Increasing spray rate drastically
- Coating at very low temperatures to freeze API
Correct Answer: Optimization of coating formulation and drying to limit mobility of API
Q29. What is the role of a gloss enhancer in tablet coating?
- To accelerate dissolution
- To increase surface shine and aesthetic appeal
- To act as disintegrant
- To reduce batch-to-batch variability of core
Correct Answer: To increase surface shine and aesthetic appeal
Q30. Which safety consideration is critical when using organic solvent-based coating systems?
- Ensure nozzles are metal
- Control for flammability and adequate ventilation/explosion-proof equipment
- Maintain cold room temperatures
- Avoid use of atomization
Correct Answer: Control for flammability and adequate ventilation/explosion-proof equipment
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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