Introduction: Excipients for novel drug delivery systems (NDDS) are multifunctional ingredients that enable targeted, controlled, and stable delivery of drugs in advanced platforms like nanoparticles, liposomes, micelles, implants, and transdermal systems. For B.Pharm students, understanding excipient selection—polymers (PLGA, PEG, HPMC), lipids, surfactants, cyclodextrins, mucoadhesives, preservatives, antioxidants, and cryoprotectants—is essential to optimize bioavailability, stability, compatibility, safety, and manufacturability. Key considerations include physicochemical properties, biocompatibility, regulatory status (GRAS/IIG), impact of sterilization, and analytical characterization (particle size, zeta potential, dissolution). Mastery of these topics builds the foundation for rational NDDS design, quality control, and regulatory compliance. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary role of excipients in nanoparticle-based NDDS?
- Act as the active therapeutic agent
- Provide structural matrix, stabilization, and surface functionality
- Replace the need for sterilization
- Increase manufacturing cost without benefit
Correct Answer: Provide structural matrix, stabilization, and surface functionality
Q2. Which polymer is commonly used for biodegradable controlled-release microspheres in NDDS?
- Polyethylene glycol (PEG)
- Polyvinyl alcohol (PVA)
- Poly(lactic-co-glycolic acid) (PLGA)
- Hydroxypropyl methylcellulose (HPMC)
Correct Answer: Poly(lactic-co-glycolic acid) (PLGA)
Q3. Which excipient class is most often used to improve solubility of poorly water-soluble drugs in NDDS?
- Bulking agents
- Solubilizers and surfactants
- Disintegrants
- Glidants
Correct Answer: Solubilizers and surfactants
Q4. Cyclodextrins are primarily used in NDDS for which purpose?
- Providing mucoadhesion
- Forming inclusion complexes to enhance solubility and stability
- Acting as a preservative
- Increasing tablet hardness
Correct Answer: Forming inclusion complexes to enhance solubility and stability
Q5. Which lipid-based excipient is commonly used to prepare liposomes?
- Cholesterol and phospholipids
- Polyethylene glycol
- Sodium starch glycolate
- Microcrystalline cellulose
Correct Answer: Cholesterol and phospholipids
Q6. Which property of an excipient most directly affects mucoadhesion in a nasal NDDS?
- Thermal conductivity
- Hydrophilicity and presence of functional groups for hydrogen bonding
- Color
- Bulk density
Correct Answer: Hydrophilicity and presence of functional groups for hydrogen bonding
Q7. Tween 80 and Poloxamer are examples of which excipient category?
- Antioxidants
- Surfactants and emulsifiers
- Buffering agents
- Preservatives
Correct Answer: Surfactants and emulsifiers
Q8. In NDDS, polyethylene glycol (PEG) is often grafted on particle surfaces primarily to:
- Increase particle density
- Provide “stealth” properties to reduce opsonization and clearance
- Serve as an active pharmaceutical ingredient
- Act as a tablet binder
Correct Answer: Provide “stealth” properties to reduce opsonization and clearance
Q9. Which excipient would you select to protect proteins during lyophilization of an NDDS?
- Cryoprotectants such as trehalose or sucrose
- Parabens
- Sodium chloride
- Magnesium stearate
Correct Answer: Cryoprotectants such as trehalose or sucrose
Q10. Zeta potential of particulate NDDS is important because it indicates:
- Drug potency
- Surface charge and colloidal stability
- pH of the formulation
- Melting point of the excipient
Correct Answer: Surface charge and colloidal stability
Q11. Which regulatory designation indicates generally recognized as safe substances often acceptable as excipients?
- ANDA
- GRAS
- ANDA AND
- PQRI
Correct Answer: GRAS
Q12. Eudragit polymers are commonly used in NDDS to achieve:
- Immediate dissolution in the stomach
- Enteric coating and pH-dependent controlled release
- Enhancing taste masking only
- Increasing tablet friability
Correct Answer: Enteric coating and pH-dependent controlled release
Q13. Which excipient is critical for maintaining isotonicity in parenteral NDDS?
- Sodium chloride or dextrose
- Magnesium stearate
- Microcrystalline cellulose
- Carboxymethyl starch
Correct Answer: Sodium chloride or dextrose
Q14. What is the main function of antioxidants in NDDS formulations?
- Enhance tablet disintegration
- Prevent oxidative degradation of labile drugs or lipids
- Act as surfactants
- Increase viscosity
Correct Answer: Prevent oxidative degradation of labile drugs or lipids
Q15. For transdermal patches, which excipient class provides skin adhesion and controlled drug release?
- Mucoadhesive polymers and pressure-sensitive adhesives
- Antioxidants
- Parabens
- Effervescent agents
Correct Answer: Mucoadhesive polymers and pressure-sensitive adhesives
Q16. In NDDS, which analytical attribute is NOT typically used to characterize nanoparticle quality?
- Particle size distribution
- Zeta potential
- Drug melting point in bulk
- Encapsulation efficiency
Correct Answer: Drug melting point in bulk
Q17. Which preservative is commonly used in ophthalmic NDDS but may cause sensitivity in some patients?
- Benzalkonium chloride
- Sodium chloride
- Trehalose
- Ethylcellulose
Correct Answer: Benzalkonium chloride
Q18. What role do mucoadhesive excipients play in nasal or buccal NDDS?
- Reduce drug absorption
- Prolong residence time and enhance local or systemic absorption
- Act as preservatives
- Prevent taste masking
Correct Answer: Prolong residence time and enhance local or systemic absorption
Q19. Which excipient modification helps improve permeation across biological membranes in NDDS?
- Adding disintegrants
- Using penetration enhancers like bile salts or surfactants
- Increasing tablet hardness
- Adding coloring agents
Correct Answer: Using penetration enhancers like bile salts or surfactants
Q20. Which test is essential to assess compatibility between drug and excipient during NDDS development?
- Dissolution only
- Drug-excipient compatibility studies using DSC, FTIR, and stress testing
- Color matching
- Tablet hardness testing
Correct Answer: Drug-excipient compatibility studies using DSC, FTIR, and stress testing
Q21. Which excipient would be most appropriate to form a thermoresponsive in situ gelling NDDS for injectable delivery?
- Poloxamer (Pluronic) copolymers
- Microcrystalline cellulose
- Sodium lauryl sulfate
- Magnesium stearate
Correct Answer: Poloxamer (Pluronic) copolymers
Q22. Which excipient property is crucial for achieving controlled release from polymeric matrices?
- Polymer glass transition temperature, hydrophobicity and biodegradation rate
- Color and odor
- Metal content only
- Tablet imprint quality
Correct Answer: Polymer glass transition temperature, hydrophobicity and biodegradation rate
Q23. In ocular NDDS, which excipient attribute minimizes irritation and maintains comfort?
- Hyperosmolarity
- Isotonicity, appropriate pH, and low preservative toxicity
- High viscosity only
- Strong surfactant concentration
Correct Answer: Isotonicity, appropriate pH, and low preservative toxicity
Q24. Which excipient is widely used as a suspending and viscosity-enhancing agent in NDDS?
- Hydroxypropyl methylcellulose (HPMC)
- Magnesium stearate
- Sodium chloride
- Calcium carbonate
Correct Answer: Hydroxypropyl methylcellulose (HPMC)
Q25. During sterilization of sterile NDDS, which excipient concern is most critical?
- Excipient thermal or radiation stability and potential degradation products
- Color change only
- Tablet shape retention
- Increase in viscosity alone
Correct Answer: Excipient thermal or radiation stability and potential degradation products
Q26. Which excipient type is commonly used to produce floating or gastroretentive NDDS?
- Low-density polymers or gas-generating agents
- Heavy metal salts
- Strong acids
- Hydrophobic waxes only
Correct Answer: Low-density polymers or gas-generating agents
Q27. Which excipient is appropriate for stabilizing lipid-based NDDS against oxidation?
- Antioxidants such as tocopherol or butylated hydroxytoluene (BHT)
- Disintegrants
- Magnesium stearate
- Calcium phosphate
Correct Answer: Antioxidants such as tocopherol or butylated hydroxytoluene (BHT)
Q28. Which concept emphasizes designing NDDS with an understanding of excipient variability, CQAs and process parameters?
- Good Laboratory Practice (GLP)
- Quality by Design (QbD)
- Good Distribution Practice (GDP)
- Randomized control
Correct Answer: Quality by Design (QbD)
Q29. In nanoparticle NDDS, what is the effect of increasing surfactant concentration during formulation?
- Increase particle aggregation invariably
- Reduce interfacial tension, leading to smaller particle size up to an optimal point
- Always increase zeta potential to positive values
- Convert nanoparticles into flakes
Correct Answer: Reduce interfacial tension, leading to smaller particle size up to an optimal point
Q30. Which excipient testing is essential for parenteral NDDS to ensure safety from leachables and extractables?
- Organoleptic testing only
- Extractables and leachables studies, and container-closure compatibility testing
- Tablet friability testing
- Disintegration testing
Correct Answer: Extractables and leachables studies, and container-closure compatibility testing
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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