Directly compressible vehicles MCQs With Answer introduces B.Pharm students to the principles and practical choices behind direct compression excipients used in tablet formulation. This concise guide covers key keywords such as directly compressible vehicles, direct compression, excipients, microcrystalline cellulose, spray-dried lactose, co-processed excipients, compressibility, flowability, lubricant sensitivity, and disintegration. It explains how vehicle selection influences tablet hardness, friability, dissolution, and manufacturability while highlighting evaluation methods like Carr’s index, Hausner ratio, and Heckel analysis. Perfect for exam preparation and formulation design, this focused review clarifies why certain diluents, binder/disintegrant systems, and co-processed materials are preferred for direct compression. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary characteristic of a vehicle suitable for direct compression?
- High hygroscopicity
- Good flowability and compressibility
- High solubility in organic solvents
- Strong bioadhesive properties
Correct Answer: Good flowability and compressibility
Q2. Which of the following excipients is a classic directly compressible microcrystalline cellulose?
- Spray-dried lactose
- Avicel PH101
- Dibasic calcium phosphate dihydrate
- Sodium starch glycolate
Correct Answer: Avicel PH101
Q3. Co-processed excipients are preferred in direct compression mainly because they:
- Require additional wet granulation
- Combine complementary functionalities like flow and compressibility
- Increase drug degradation during compression
- Act as enteric coatings
Correct Answer: Combine complementary functionalities like flow and compressibility
Q4. Which parameter is commonly used to evaluate powder flow for direct compression?
- pH value
- Carr’s index
- Optical rotation
- Melting point
Correct Answer: Carr’s index
Q5. A Hausner ratio greater than 1.25 generally indicates:
- Excellent flow
- Poor flow
- High solubility
- Low compressibility
Correct Answer: Poor flow
Q6. Which directly compressible filler is insoluble and commonly used when moisture sensitivity is a concern?
- Spray-dried lactose
- Microcrystalline cellulose
- Dibasic calcium phosphate (anhydrous)
- Sorbitol
Correct Answer: Dibasic calcium phosphate (anhydrous)
Q7. Which superdisintegrant is most commonly used in direct compression formulations?
- Croscarmellose sodium
- Methylcellulose
- Povidone K90
- Sodium lauryl sulfate
Correct Answer: Croscarmellose sodium
Q8. Lubricant sensitivity in directly compressible blends typically results in:
- Improved tablet hardness
- Reduced tablet tensile strength
- Increased disintegration time due to hydrophobic film formation
- Increased powder solubility
Correct Answer: Increased disintegration time due to hydrophobic film formation
Q9. Which analytical plot assesses powder densification under compression and helps study compressibility?
- Heckel plot
- Higuchi plot
- Noyes‑Whitney plot
- Van’t Hoff plot
Correct Answer: Heckel plot
Q10. Spray-dried lactose is favored in direct compression because it provides:
- High oil absorption
- Balanced particle size, good flow and compressibility
- Strong binding when wet granulated only
- Enteric protection
Correct Answer: Balanced particle size, good flow and compressibility
Q11. Which property of microcrystalline cellulose (MCC) makes it an excellent binder and filler in direct compression?
- Plastic deformation under pressure
- Brittle fragmentation only
- High melting point
- Strong acidic nature
Correct Answer: Plastic deformation under pressure
Q12. Prosolv SMCC is an example of a:
- Superdisintegrant
- Co-processed excipient combining MCC and silicon dioxide
- Lubricant
- Flavoring agent
Correct Answer: Co-processed excipient combining MCC and silicon dioxide
Q13. Which test measures tablet tendency to lose mass due to mechanical shock?
- Friability test
- Dissolution test
- Disintegration test
- pH test
Correct Answer: Friability test
Q14. Excessive elastic recovery of a directly compressed tablet often causes:
- Improved dissolution
- Capping and lamination
- Faster disintegration
- Reduced friability
Correct Answer: Capping and lamination
Q15. Which excipient acts primarily as a diluent and has good direct compression properties and sweetness?
- Cellulose acetate
- Sorbitol (e.g., Parteck, Pearlitol)
- Magnesium stearate
- Polyvinylpyrrolidone (PVP)
Correct Answer: Sorbitol (e.g., Parteck, Pearlitol)
Q16. What is the main disadvantage of using high levels of magnesium stearate in direct compression blends?
- It increases tablet porosity dramatically
- It causes excessive lubrication leading to reduced bonding and hardness
- It acts as a disintegrant
- It increases powder reactivity
Correct Answer: It causes excessive lubrication leading to reduced bonding and hardness
Q17. Which excipient is known as a co-processed lactose-based directly compressible vehicle?
- Cellactose
- CCM‑102
- Ethylcellulose
- Sodium chloride
Correct Answer: Cellactose
Q18. Particle size distribution affects direct compression by influencing:
- Only chemical stability
- Flow, packing behavior, and compression properties
- Tablet color exclusively
- Evaporation rate of solvent
Correct Answer: Flow, packing behavior, and compression properties
Q19. Which mechanism primarily allows superdisintegrants to promote tablet breakup?
- Formation of hydrophobic films
- Wicking and rapid swelling
- Chelation of metal ions
- Covalent crosslinking
Correct Answer: Wicking and rapid swelling
Q20. A directly compressible blend showing poor content uniformity likely needs improvement in:
- Tablet coatings
- Blend homogeneity and particle size matching
- pH of dissolution medium
- Temperature during storage only
Correct Answer: Blend homogeneity and particle size matching
Q21. Which instrumentally determined property directly correlates to powder bulk density changes under tapping?
- Angle of repose
- Tapped density
- Melting range
- Thermal conductivity
Correct Answer: Tapped density
Q22. In direct compression, why are lubricants added at the lowest effective concentration?
- To increase dissolution time
- To avoid excessive reduction in compressibility and tablet strength
- To prevent tablet coloration
- To promote microbial growth
Correct Answer: To avoid excessive reduction in compressibility and tablet strength
Q23. Which excipient provides both sweetening and direct compression functionality often used in chewable tablets?
- Lactose monohydrate
- Sorbitol
- Microcrystalline cellulose
- Calcium stearate
Correct Answer: Sorbitol
Q24. A formulation strategy to improve flow and compressibility without wet granulation is to use:
- High amounts of solvent
- Co-processed excipients
- Only fine powders
- Excessive superdisintegrant
Correct Answer: Co-processed excipients
Q25. Which test indicates the cohesiveness of a powder and is derived from tapped and bulk density?
- Hausner ratio
- pKa value
- Optical density
- Viscosity
Correct Answer: Hausner ratio
Q26. Which is a likely consequence of blending a moisture-sensitive drug with highly hygroscopic directly compressible excipient?
- Improved tablet stability
- Drug degradation and poor flow due to agglomeration
- Instant dissolution improvement
- Decreased tablet weight variability only
Correct Answer: Drug degradation and poor flow due to agglomeration
Q27. Compression force optimization in direct compression mainly influences:
- Only tablet color
- Tablet porosity, hardness, and dissolution profile
- pH of the formulation
- Chemical structure of drug
Correct Answer: Tablet porosity, hardness, and dissolution profile
Q28. Which of the following is NOT typically a function of a directly compressible vehicle?
- Provide tablet bulk (diluent)
- Enhance particle bonding during compression
- Serve as an active pharmaceutical ingredient
- Improve flowability
Correct Answer: Serve as an active pharmaceutical ingredient
Q29. Which excipient class is commonly added in small amounts to minimize die wall friction and sticking?
- Superdisintegrants
- Lubricants (e.g., magnesium stearate)
- Fillers
- Colorants
Correct Answer: Lubricants (e.g., magnesium stearate)
Q30. For a poorly flowing active ingredient, the best approach for direct compression is to:
- Use the API alone with high compression force
- Co-process the API with compatible excipients or use carrier excipients to improve flow
- Add more superdisintegrant only
- Avoid blending and compress immediately
Correct Answer: Co-process the API with compatible excipients or use carrier excipients to improve flow
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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