Formulation of coating composition MCQs With Answer is a focused review designed for B. Pharm students to master coating science. This introduction covers coating polymers, plasticizers, pigments, solvents, surfactants, and functional coatings such as enteric and sustained-release systems. It highlights formulation variables, process parameters (spray rate, inlet temperature, coating weight gain), common defects and evaluation tests (thickness, adhesion, dissolution). Keywords include film coating, coating polymers, plasticizers, solvent systems, enteric coating, sustained-release coating, and tablet coating evaluation. Clear understanding of these concepts improves product quality and performance. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary function of a film coating on oral tablets?
- To provide controlled drug release only
- To improve stability, mask taste, and enhance appearance
- To increase tablet hardness by compression
- To reduce tablet disintegration time
Correct Answer: To improve stability, mask taste, and enhance appearance
Q2. Which of the following is a commonly used film-forming polymer for aqueous coatings?
- Cellulose acetate phthalate
- Hydroxypropyl methylcellulose (HPMC)
- Polyvinyl alcohol in organic solvent only
- Polyethylene glycol 400
Correct Answer: Hydroxypropyl methylcellulose (HPMC)
Q3. What is the role of a plasticizer in a coating composition?
- Increase the coating’s melting point
- Enhance film flexibility and reduce brittleness
- Act as a solvent for the polymer
- Improve tablet disintegration
Correct Answer: Enhance film flexibility and reduce brittleness
Q4. Which plasticizer is frequently used in aqueous film coatings?
- Triethyl citrate
- Sodium lauryl sulfate
- Titanium dioxide
- Cellulose acetate
Correct Answer: Triethyl citrate
Q5. Titanium dioxide in coating formulations is primarily used as:
- A plasticizer
- An opacifier and pigment
- A disintegrant
- A surfactant
Correct Answer: An opacifier and pigment
Q6. Enteric coatings are designed to:
- Release drug immediately in the stomach
- Protect drug from intestinal enzymes
- Resist gastric acid and dissolve in the intestine
- Increase solubility in gastric fluid
Correct Answer: Resist gastric acid and dissolve in the intestine
Q7. Which polymer is commonly used for enteric coatings?
- Ethylcellulose
- Eudragit L or cellulose acetate phthalate
- HPMC alone
- Polyethylene glycol 1000
Correct Answer: Eudragit L or cellulose acetate phthalate
Q8. Ethylcellulose is primarily used in coatings to:
- Provide aqueous solubility
- Impart water-insoluble sustained-release properties
- Act as a disintegrant
- Serve as a coloring agent
Correct Answer: Impart water-insoluble sustained-release properties
Q9. Which coating defect results from too rapid solvent evaporation producing a rough surface?
- Blistering
- Orange peel
- Picking
- Capping
Correct Answer: Orange peel
Q10. What does coating weight gain refer to?
- The increase in tablet hardness after coating
- The percentage increase in tablet weight due to applied coating
- The weight of solvent lost during coating
- The increase in batch yield after coating
Correct Answer: The percentage increase in tablet weight due to applied coating
Q11. In fluidized bed coating, which process advantage is notable?
- Low heat transfer and long processing time
- Simultaneous drying and coating with good uniformity
- Only suitable for large tablets
- Requires high organic solvent volumes
Correct Answer: Simultaneous drying and coating with good uniformity
Q12. A surfactant in a coating formulation mainly functions to:
- Increase polymer molecular weight
- Improve wetting and dispersion of pigments
- Act as an enteric agent
- Reduce tablet friability
Correct Answer: Improve wetting and dispersion of pigments
Q13. Which test assesses the uniformity of coating thickness across a tablet population?
- Friability test
- Coating weight gain determination and thickness measurement
- Disintegration in simulated gastric fluid
- Loss on drying
Correct Answer: Coating weight gain determination and thickness measurement
Q14. Which solvent system is preferred for safety and environmental reasons in modern coating?
- Chloroform-based organic systems
- Water-based (aqueous) coating systems
- Hexane-based solvents
- Cyclohexane mixtures
Correct Answer: Water-based (aqueous) coating systems
Q15. Which mechanism describes drug release through a non-swellable, water-insoluble coating?
- Diffusion-controlled release
- Matrix erosion
- pH-triggered dissolution only
- Immediate disintegration
Correct Answer: Diffusion-controlled release
Q16. What causes coating blistering in tablets?
- Inadequate plasticizer concentration only
- Trapped air or solvent vapor expansion under the film
- Use of too much pigment
- Excessive tablet compression force
Correct Answer: Trapped air or solvent vapor expansion under the film
Q17. Which coating additive enhances gloss and smoothness of the film?
- Antioxidants
- Glossants or leveling agents
- Disintegrants
- Buffering agents
Correct Answer: Glossants or leveling agents
Q18. What is the effect of increasing coating weight gain on a sustained-release tablet?
- Decreases diffusion path length and speeds release
- Increases diffusion path length and slows release
- Has no effect on release rate
- Always causes immediate release
Correct Answer: Increases diffusion path length and slows release
Q19. Which of the following is a quality attribute specifically evaluated for coated tablets?
- Moisture sorption of powder blend only
- Coating adhesion (peel strength)
- Compressibility index of granules
- Bulk density of API
Correct Answer: Coating adhesion (peel strength)
Q20. Osmotic pump coatings rely primarily on which principle for drug release?
- Polymer erosion only
- Osmotic pressure driving drug solution through an orifice
- pH-dependent solubility of the coating polymer
- Immediate dissolution in gastric fluid
Correct Answer: Osmotic pressure driving drug solution through an orifice
Q21. Which coating defect is characterized by partial removal of film from tablet surface due to mechanical stress?
- Orange peel
- Picking and peeling
- Blistering
- Sticking
Correct Answer: Picking and peeling
Q22. A plasticizer concentration that is too high can cause:
- More brittle film formation
- Sticky soft film and increased tackiness
- Complete insolubility in solvents
- Immediate drug degradation
Correct Answer: Sticky soft film and increased tackiness
Q23. Which polymer is typically used for sustained-release coatings in aqueous systems?
- HPMC combined with ethylcellulose or coated as multiparticulate film
- Sodium starch glycolate
- Talc as primary polymer
- Titanium dioxide as the coating matrix
Correct Answer: HPMC combined with ethylcellulose or coated as multiparticulate film
Q24. What parameter is critical to control to avoid tablet sticking during coating?
- Tablet color only
- Inlet air temperature and spray rate
- API particle size only
- Final tablet packaging
Correct Answer: Inlet air temperature and spray rate
Q25. Which analytical method is commonly used to evaluate coating integrity and thickness nondestructively?
- Visual inspection only
- Ultrasound or optical microscopy and micrometer after cross-sectioning
- pH titration
- Melting point determination
Correct Answer: Ultrasound or optical microscopy and micrometer after cross-sectioning
Q26. Which ingredient would you include to improve pigment dispersion in a coating suspension?
- Plasticizer only
- Surfactant or dispersing agent
- Enteric polymer
- Sodium chloride
Correct Answer: Surfactant or dispersing agent
Q27. What is the likely consequence of using excessive spray rate in pan coating?
- Improved drying and no defects
- Insufficient drying leading to tackiness and agglomeration
- Lower coating efficiency with thinner films
- Immediate polymer crosslinking
Correct Answer: Insufficient drying leading to tackiness and agglomeration
Q28. Which concept is important for designing robust coating formulations under Quality by Design (QbD)?
- Ignoring critical process parameters
- Identification of critical quality attributes and critical process parameters
- Using the maximum possible solvent
- Minimizing API characterization
Correct Answer: Identification of critical quality attributes and critical process parameters
Q29. Which excipient helps prevent settling of pigment particles in coating suspensions?
- Anti-tacking agent
- Thickening or suspending agent (e.g., xanthan gum)
- Plasticizer only
- Enteric polymer
Correct Answer: Thickening or suspending agent (e.g., xanthan gum)
Q30. For a pH-dependent enteric coating, which in vitro test is essential?
- Disintegration at room temperature only
- Dissolution testing in sequential acidic then intestinal pH media
- Thermogravimetric analysis only
- Loss on drying at 105°C only
Correct Answer: Dissolution testing in sequential acidic then intestinal pH media
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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