Coating materials for tablets and capsules MCQs With Answer

Coating materials for tablets and capsules MCQs With Answer

This concise introduction covers coating materials used in pharmaceutical film, sugar, and enteric coatings for tablets and capsules, emphasizing polymers, plasticizers, solvents, pigments, opacifiers, and equipment. Key topics include commonly used polymers (HPMC, ethylcellulose, CAP, Eudragit), aqueous versus organic systems, taste-masking, controlled-release coatings, coating defects and troubleshooting, and regulatory concerns such as residual solvents and stability. Terms like film coating, enteric coating, plasticizer, aqueous dispersion, opacifier, and weight gain are explained for B.Pharm students preparing for exams. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which polymer is most commonly used for aqueous film coating due to its good film-forming properties and easy solubility?

• Ethylcellulose
• Hydroxypropyl methylcellulose (HPMC)
• Cellulose acetate phthalate (CAP)
• Polyvinyl acetate phthalate

Correct Answer: Hydroxypropyl methylcellulose (HPMC)

Q2. Which coating polymer is typically used for enteric protection and dissolves at higher pH in the intestine?

• Hydroxypropyl cellulose (HPC)
• Ethylcellulose
• Eudragit L (methacrylic acid copolymer)
• Polyvinyl alcohol

Correct Answer: Eudragit L (methacrylic acid copolymer)

Q3. What is the primary function of a plasticizer in a film coating formulation?

• Increase tablet weight
• Improve color intensity
• Lower polymer glass transition temperature to improve film flexibility
• Act as a preservative

Correct Answer: Lower polymer glass transition temperature to improve film flexibility

Q4. Which of the following is a commonly used plasticizer in pharmaceutical film coatings?

• Titanium dioxide
• Triethyl citrate
• Sodium lauryl sulfate
• Magnesium stearate

Correct Answer: Triethyl citrate

Q5. Which coating type primarily aims to mask bad taste and odor of an active pharmaceutical ingredient?

• Enteric coating
• Sugar coating
• Film coating for taste-masking
• Controlled-release coating

Correct Answer: Film coating for taste-masking

Q6. Which opacifier/pigment is most widely used to provide whiteness and opacity in tablet coatings?

• Iron oxide
• Riboflavin
• Titanium dioxide
• Carnauba wax

Correct Answer: Titanium dioxide

Q7. Which coating material is water-insoluble and commonly used to produce moisture barrier or delayed-release coatings?

• Ethylcellulose
• Hydroxypropyl methylcellulose
• Polyethylene glycol
• Polyvinylpyrrolidone (PVP)

Correct Answer: Ethylcellulose

Q8. In a fluid-bed coating (Wurster process), what is the main mechanism for applying coating solution to particles?

• Rotary tumbling with baffles
• Spraying upward in a fluidized column with downward return
• Dipping tablets manually
• Extrusion through a die

Correct Answer: Spraying upward in a fluidized column with downward return

Q9. Which coating defect is most likely caused by too high inlet temperature, rapid solvent evaporation, or low plasticizer content?

• Mottling
• Orange peel or rough surface
• Peeling
• Blistering due to gas formation

Correct Answer: Orange peel or rough surface

Q10. Which polymer is a commonly used aqueous dispersion of ethylcellulose marketed for controlled-release coating?

• Aquacoat
• Opadry
• Kollicoat IR
• Povidone K30

Correct Answer: Aquacoat

Q11. What does the term “weight gain” in coating processes refer to?

• Increase in tablet mass due to moisture uptake after coating
• Percentage increase in tablet weight due to deposited coating material
• Amount of plasticizer added to the coating solution
• Weight of coating equipment

Correct Answer: Percentage increase in tablet weight due to deposited coating material

Q12. Which polymer is preferable for making an immediate-release, water-soluble film coat that dissolves rapidly in gastric fluid?

• Ethylcellulose
• Hydroxypropyl methylcellulose (HPMC)
• Cellulose acetate phthalate (CAP)
• Eudragit RS

Correct Answer: Hydroxypropyl methylcellulose (HPMC)

Q13. Which solvent class is preferred for safety and environmental reasons in modern pharmaceutical coating?

• Chlorinated organic solvents
• Aqueous (water-based) systems
• Benzene-based solvents
• Neat acetone

Correct Answer: Aqueous (water-based) systems

Q14. Which coating defect results from non-uniform pigment distribution or incompatibility between pigment and substrate?

• Mottling
• Bridging
• Picking
• Blooming

Correct Answer: Mottling

Q15. Eudragit RS and RL differ primarily in which property affecting release?

• Color
• Degree of permeability due to quaternary ammonium groups
• Solubility in water at neutral pH
• Melting point

Correct Answer: Degree of permeability due to quaternary ammonium groups

Q16. Which analytical parameter is commonly measured to assess uniformity of a film coat across a tablet batch?

• Disintegration time only
• Coating thickness or % weight gain and appearance uniformity
• API particle size only
• Melting point of polymer

Correct Answer: Coating thickness or % weight gain and appearance uniformity

Q17. For enteric coating, which polymer has been adopted to avoid phthalate concerns associated with CAP?

• HPMC acetate succinate (HPMCAS)
• Hydroxyethyl cellulose
• Polyvinyl alcohol
• Ethylcellulose

Correct Answer: HPMC acetate succinate (HPMCAS)

Q18. Which component in coating formulations improves adhesion of the film to the tablet core?

• Opacifier
• Plasticizer
• Adhesive binder such as PVP (polyvinylpyrrolidone)
• Colorant only

Correct Answer: Adhesive binder such as PVP (polyvinylpyrrolidone)

Q19. What is a common purpose of talc in coating suspensions?

• Act as plasticizer
• Function as anti-tacking and glidant to reduce sticking
• Provide enteric property
• Act as primary film former

Correct Answer: Function as anti-tacking and glidant to reduce sticking

Q20. Which coating method is most suitable for large-scale, high-throughput tablet coating with good mixing?

• Hand-dipping
• Traditional rotating coating pan with perforation or perforated pan coater
• Layer-by-layer vacuum deposition
• Hot-melt extrusion of individual tablets

Correct Answer: Traditional rotating coating pan with perforation or perforated pan coater

Q21. Which property of a polymer most influences its film flexibility and tendency to crack without plasticizer?

• Molecular weight only
• Glass transition temperature (Tg)
• Melting point only
• Density

Correct Answer: Glass transition temperature (Tg)

Q22. When coating gelatin capsules, which challenge is particularly important to address?

• Capsule melting due to high coating inlet temperature and solvent interaction
• Excessive tablet hardness
• API incompatibility with HPMC only
• Reduced dissolution due to sugar coating

Correct Answer: Capsule melting due to high coating inlet temperature and solvent interaction

Q23. Which of the following is NOT a mechanism by which coatings can modify drug release?

• Diffusion through a polymer film
• Dissolution-controlled release of a soluble coating
• Chemical conversion of API into new active molecules
• Erosion of the coating matrix

Correct Answer: Chemical conversion of API into new active molecules

Q24. Which coating defect is characterized by small dome-shaped elevations and is often due to trapped air or rapid solvent evaporation?

• Pitting
• Blistering
• Cracking
• Mottling

Correct Answer: Blistering

Q25. Which ingredient is primarily responsible for imparting gloss to a film-coated tablet?

• Plasticizer and polishing agents such as shellac or PEG
• Opacifier like titanium dioxide only
• Binder like PVP only
• Disintegrant like croscarmellose sodium

Correct Answer: Plasticizer and polishing agents such as shellac or PEG

Q26. Which methacrylate-based polymer would you choose to formulate a sustained-release coating that is water-insoluble but permeable?

• Eudragit E (cationic, gastric soluble)
• Eudragit RL (permeable, water-insoluble)
• Eudragit L100 (enteric)
• Hydroxypropyl cellulose (HPC)

Correct Answer: Eudragit RL (permeable, water-insoluble)

Q27. What is the effect of increasing coating solids concentration in the spray solution while keeping spray rate constant?

• Longer drying time per droplet
• Reduced number of spray passes and higher per-pass weight gain, but increased risk of spray nozzles clogging and poor film formation
• No effect on coating process
• Always improves film uniformity

Correct Answer: Reduced number of spray passes and higher per-pass weight gain, but increased risk of spray nozzles clogging and poor film formation

Q28. Which analytical test is most appropriate to confirm an enteric coat is intact in simulated gastric fluid?

• Disintegration test in acidic medium followed by dissolution in buffer to check release
• Melting point determination
• Assay of API content only
• Loss on drying

Correct Answer: Disintegration test in acidic medium followed by dissolution in buffer to check release

Q29. Which coating raw material raises regulatory concerns due to residual monomers or solvents and is being phased out in some formulations?

• Water
• Chlorinated solvents and certain phthalate esters
• Triethyl citrate
• Titanium dioxide

Correct Answer: Chlorinated solvents and certain phthalate esters

Q30. For taste-masking via coating, what minimum properties should the coating provide?

• Immediate dissolution in saliva
• Physical barrier in saliva with rapid dissolution in gastric fluid; good adhesion and uniformity
• Enteric resistance only
• High porosity to allow diffusion in the mouth

Correct Answer: Physical barrier in saliva with rapid dissolution in gastric fluid; good adhesion and uniformity

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