Selection of excipients in pharmaceutical formulations is a core topic for B.Pharm students focusing on how inert and functional additives affect drug stability, bioavailability, manufacturability and patient acceptability. Understanding excipient classification, selection criteria, physicochemical properties, compatibility testing, regulatory status and functionality—such as fillers, binders, disintegrants, lubricants, diluents, surfactants, preservatives, solubilizers and release-modifying polymers—is essential for robust formulation design. Practical considerations include moisture sensitivity, HLB value, particle size, flow, compressibility and potential drug–excipient interactions (e.g., Maillard reaction, oxidation). This knowledge supports rational excipient choice for tablets, capsules, suspensions, emulsions and controlled-release systems. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which property is most critical when selecting a filler for direct compression?
- High hygroscopicity
- Good flowability and compressibility
- High solubility in water
- Strong surfactant activity
Correct Answer: Good flowability and compressibility
Q2. Which excipient is commonly used as a binder in wet granulation due to its solubility and film-forming ability?
- Microcrystalline cellulose
- Lactose monohydrate
- Povidone (PVP)
- Magnesium stearate
Correct Answer: Povidone (PVP)
Q3. Which disintegrant mechanism involves swelling to break the tablet apart?
- Wicking
- Swelling
- Enzymatic degradation
- Surface erosion
Correct Answer: Swelling
Q4. Which lubricant is most likely to slow tablet dissolution if used excessively?
- Magnesium stearate
- Sodium starch glycolate
- Croscarmellose sodium
- Starch
Correct Answer: Magnesium stearate
Q5. For enhancing solubility of a poorly soluble drug, which excipient class is most appropriate?
- Hydrophobic fillers
- Solubilizers and surfactants
- Glidants
- Preservatives
Correct Answer: Solubilizers and surfactants
Q6. Which polymer is commonly used for sustained-release matrix tablets due to swelling and gel formation?
- Hydroxypropyl methylcellulose (HPMC)
- Polyethylene glycol (PEG 400)
- Polyvinylpyrrolidone (PVP)
- Lactose
Correct Answer: Hydroxypropyl methylcellulose (HPMC)
Q7. Which excipient can cause Maillard-type browning with primary amine drugs?
- Microcrystalline cellulose
- Lactose
- Ethylcellulose
- Sodium lauryl sulfate
Correct Answer: Lactose
Q8. Which test is most useful for detecting drug–excipient compatibility issues during preformulation?
- Dissolution testing only
- Accelerated stability studies with stressed conditions
- Simple solubility in water
- Visual color assessment only
Correct Answer: Accelerated stability studies with stressed conditions
Q9. Which excipient grade indicates suitability for pharmaceutical use and compliance with pharmacopeial standards?
- Food grade
- Reagent grade
- Pharmaceutical (pharmacopoeial) grade
- Industrial grade
Correct Answer: Pharmaceutical (pharmacopoeial) grade
Q10. Which excipient is typically added to liquid formulations to prevent microbial growth?
- Antioxidant
- Preservative (e.g., parabens)
- Surfactant
- Disintegrant
Correct Answer: Preservative (e.g., parabens)
Q11. What is the primary function of a glidant in tablet formulations?
- Improve solubility
- Enhance powder flow
- Act as a disintegrant
- Serve as a preservative
Correct Answer: Enhance powder flow
Q12. When selecting excipients for oral suspensions, which property of the suspending agent is most important?
- Ability to form a stable viscosity that prevents rapid sedimentation
- Strong antimicrobial activity
- High melting point
- Low viscosity at all concentrations
Correct Answer: Ability to form a stable viscosity that prevents rapid sedimentation
Q13. Which surfactant class is characterized by having both hydrophilic and lipophilic balance (HLB) values useful for emulsion selection?
- Anionic surfactants only
- Nonionic surfactants with defined HLB
- Cationic surfactants only
- Strong acids
Correct Answer: Nonionic surfactants with defined HLB
Q14. Which excipient is commonly used as a tablet diluent and is water-soluble, affecting dissolution positively?
- Microcrystalline cellulose
- Lactose
- Magnesium stearate
- Hydrogenated vegetable oil
Correct Answer: Lactose
Q15. Which excipient acts as a chelating agent to reduce metal-catalyzed oxidation?
- EDTA (ethylenediaminetetraacetic acid)
- Sodium chloride
- Propylene glycol
- Stearic acid
Correct Answer: EDTA (ethylenediaminetetraacetic acid)
Q16. For a moisture-sensitive drug, which excipient property is most undesirable?
- Low bulk density
- Hygroscopic nature
- Good compressibility
- Neutral pH
Correct Answer: Hygroscopic nature
Q17. Which plasticizer is commonly used in film coatings to impart flexibility?
- Glycerin or polyethylene glycol (PEG)
- Sodium bicarbonate
- Calcium phosphate
- Magnesium oxide
Correct Answer: Glycerin or polyethylene glycol (PEG)
Q18. Which excipient selection consideration is most relevant for parenteral formulations?
- Particle size and particulate limits
- Tablet hardness
- Disintegration time
- Film-coat aesthetics
Correct Answer: Particle size and particulate limits
Q19. Which polymer is often used as an enteric coating to protect drug release in the stomach?
- Hydroxypropyl methylcellulose (HPMC)
- Polyvinylpyrrolidone (PVP)
- Cellulose acetate phthalate (CAP)
- Magnesium stearate
Correct Answer: Cellulose acetate phthalate (CAP)
Q20. What is a potential negative effect of excessive glidant use in a formulation?
- Improved dissolution rate
- Reduced tablet tensile strength
- Enhanced wetting
- Increased bioavailability
Correct Answer: Reduced tablet tensile strength
Q21. Which excipient is commonly used to increase wetting of hydrophobic drug particles?
- Surfactant (e.g., sodium lauryl sulfate)
- Microcrystalline cellulose
- Calcium phosphate
- Sucrose
Correct Answer: Surfactant (e.g., sodium lauryl sulfate)
Q22. Which excipient is preferred for direct compression because of excellent compressibility and inertness?
- Starch
- Microcrystalline cellulose
- Polyethylene glycol
- Sodium lauryl sulfate
Correct Answer: Microcrystalline cellulose
Q23. In controlled-release bead formulations, which excipient type controls drug release by forming a water-insoluble barrier?
- Hydrophilic fillers
- Hydrophobic polymers like ethylcellulose
- Disintegrants
- Sweeteners
Correct Answer: Hydrophobic polymers like ethylcellulose
Q24. Which excipient can act both as a humectant and stability-improving solvent in liquid formulations?
- Propylene glycol
- Magnesium stearate
- Starch
- Microcrystalline cellulose
Correct Answer: Propylene glycol
Q25. When choosing excipients, which regulatory concept requires demonstrable safety and quality for the intended use?
- GRAS and pharmacopeial compliance
- Only cost minimization
- Color matching
- Only supplier reputation
Correct Answer: GRAS and pharmacopeial compliance
Q26. Which antioxidant is commonly used to protect formulations from oxidation?
- Butylated hydroxytoluene (BHT) or ascorbic acid
- Magnesium stearate
- Calcium carbonate
- Sodium chloride
Correct Answer: Butylated hydroxytoluene (BHT) or ascorbic acid
Q27. Which excipient is most likely to interact with acidic drugs through ionic binding?
- Cationic polymers
- Anionic excipients like sodium lauryl sulfate
- Neutral sugars
- Hydrophobic oils
Correct Answer: Cationic polymers
Q28. For oral fast-dissolving tablets, which excipient type is crucial to achieve rapid disintegration in the mouth?
- Superdisintegrants (e.g., croscarmellose)
- Hydrophobic waxes
- Slow-release polymers
- Heavy metal salts
Correct Answer: Superdisintegrants (e.g., croscarmellose)
Q29. Which excipient selection step involves evaluation of thermal, moisture and photostability of blends?
- Clinical trials
- Compatibility and stability studies
- Marketing analysis
- Tablet coating only
Correct Answer: Compatibility and stability studies
Q30. Which excipient can be used to increase intestinal permeability and improve absorption of certain drugs?
- Permeation enhancers (e.g., bile salts, certain surfactants)
- Simple sugars
- Neutral fillers
- Antioxidants only
Correct Answer: Permeation enhancers (e.g., bile salts, certain surfactants)
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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