Properties and applications of polymers in NDDS MCQs With Answer

Properties and applications of polymers in NDDS MCQs With Answer are designed to help M. Pharm students master how polymer chemistry and physics translate into controlled, targeted, and patient-friendly drug delivery. This quiz revises essential attributes—molecular weight, polydispersity, crystallinity, glass transition temperature (Tg), crosslinking, degradability, mucoadhesion, and stimuli-responsiveness—and connects them to real NDDS formats such as nanoparticles, hydrogels, microspheres, micelles, and dendrimers. You will also review release kinetics models, surface engineering (e.g., PEGylation), colloidal stability, and polymer–mucus interactions, along with material choices like PLGA, chitosan, alginate, Eudragit, HPMC, and PEG. Each MCQ includes the correct answer to support self-assessment and exam preparation for MPH 102T.

Q1. In polymeric NDDS, the position of the glass transition temperature (Tg) relative to 37°C primarily affects which functional attribute?

• Drug–polymer chemical compatibility during sterilization
• Polymer chain mobility and drug diffusion through the matrix
• Aqueous solubility of hydrophobic drugs
• Protein binding affinity on nanoparticle surfaces

Correct Answer: Polymer chain mobility and drug diffusion through the matrix

Q2. The dominant mechanism enabling chitosan-based mucoadhesion in NDDS is:

• Hydrophobic interactions with mucin glycoproteins
• Electrostatic interaction between protonated amines and sialic acid residues
• Disulfide bond formation with cysteine-rich mucin domains
• Van der Waals interactions with epithelial membranes

Correct Answer: Electrostatic interaction between protonated amines and sialic acid residues

Q3. PEGylation of polymeric nanoparticles is primarily used to:

• Increase drug loading via ionic complexation
• Enhance opsonization for rapid RES clearance
• Provide steric stabilization and reduce protein adsorption
• Trigger pH-responsive endosomal escape

Correct Answer: Provide steric stabilization and reduce protein adsorption

Q4. The initial burst release from polymeric nanoparticles is most directly driven by:

• Drug molecules localized at or near the particle surface
• High crystallinity of the polymer matrix
• Low glass transition temperature (Tg) of the polymer
• Increased ionic strength of the external medium

Correct Answer: Drug molecules localized at or near the particle surface

Q5. For polymers used in NDDS, a low polydispersity index (PDI) typically indicates:

• Broader molecular weight distribution and unpredictable degradation
• Narrow molecular weight distribution and more reproducible release
• Higher crystallinity and faster erosion
• Better emulsification during nanoparticle formation

Correct Answer: Narrow molecular weight distribution and more reproducible release

Q6. For enteric and distal intestinal targeting by pH-triggered dissolution, a suitable polymer is:

• Eudragit S 100 (dissolves above pH ~7)
• Chitosan (soluble in acidic pH)
• HPMC (pH-independent dissolution)
• PLGA (non–pH-responsive)

Correct Answer: Eudragit S 100 (dissolves above pH ~7)

Q7. The classical Higuchi model for matrix systems is most valid when:

• The polymer matrix swells extensively during release
• Drug diffusion coefficient and matrix porosity remain approximately constant
• The system undergoes rapid surface erosion
• Drug is released primarily by polymer relaxation (Case II transport)

Correct Answer: Drug diffusion coefficient and matrix porosity remain approximately constant

Q8. A cylindrical hydrogel device exhibits a Korsmeyer–Peppas release exponent n = 0.50. This suggests:

• Pure Fickian diffusion
• Case II transport dominated by polymer relaxation
• Anomalous (non-Fickian) transport with combined diffusion and relaxation
• Zero-order release kinetics

Correct Answer: Anomalous (non-Fickian) transport with combined diffusion and relaxation

Q9. Increasing crosslinking density in a hydrogel used for NDDS generally:

• Increases mesh size and accelerates drug diffusion
• Decreases mechanical strength and reduces elasticity
• Decreases swelling and slows diffusional drug release
• Has no impact on release kinetics

Correct Answer: Decreases swelling and slows diffusional drug release

Q10. Which polymer is cationic at physiological pH and can transiently open tight junctions to enhance paracellular transport?

• Sodium alginate
• Hyaluronic acid
• Chitosan
• PLGA

Correct Answer: Chitosan

Q11. Polyanhydride-based NDDS typically display surface erosion because:

• They are highly hydrophilic, enabling rapid bulk water penetration
• Their hydrophobic backbones limit water ingress while anhydride bonds hydrolyze at the surface
• They have very high glass transition temperatures
• They form crystalline lamellae that exclude drug molecules

Correct Answer: Their hydrophobic backbones limit water ingress while anhydride bonds hydrolyze at the surface

Q12. Regarding zeta potential and polymeric nanoparticle stability, which statement is most accurate?

• Only particles with |ζ| ≥ 30 mV are stable; steric stabilization is ineffective
• Near-neutral ζ-potential particles can be colloidally stable if sterically stabilized (e.g., PEGylated)
• High positive ζ-potential always reduces cytotoxicity
• ζ-potential does not influence protein corona formation

Correct Answer: Near-neutral ζ-potential particles can be colloidally stable if sterically stabilized (e.g., PEGylated)

Q13. PAMAM dendrimer toxicity can be mitigated primarily by:

• Increasing terminal primary amine density
• Surface acetylation or PEGylation to mask cationic groups
• Raising generation number to increase size
• Forming inclusion complexes with cyclodextrins

Correct Answer: Surface acetylation or PEGylation to mask cationic groups

Q14. To extend PLGA microsphere release from weeks to months for depot injections, a common and effective strategy is to:

• Decrease polymer molecular weight and increase glycolic content
• Increase polymer molecular weight and lactide content
• Add hydrophilic surfactants to the matrix
• Use highly porous particle architectures

Correct Answer: Increase polymer molecular weight and lactide content

Q15. A classic thermoresponsive polymer exhibiting an LCST around 32°C, often studied for injectable gels, is:

• Poly(N-isopropylacrylamide) (PNIPAM)
• Polycaprolactone (PCL)
• Hydroxypropyl methylcellulose (HPMC)
• Poly(lactic-co-glycolic acid) (PLGA)

Correct Answer: Poly(N-isopropylacrylamide) (PNIPAM)

Q16. Hyaluronic acid is advantageous in ocular NDDS primarily due to its:

• Strong hydrophobic interactions with tear film lipids
• Viscoelasticity and high water-binding capacity improving retention
• Intrinsic anti-bacterial activity at low concentrations
• Ability to form covalent bonds with corneal epithelium

Correct Answer: Viscoelasticity and high water-binding capacity improving retention

Q17. Polysaccharides such as pectin and guar gum enable colon-specific delivery mainly because they:

• Dissolve rapidly in gastric acid
• Are degraded by colonic bacterial enzymes
• Undergo rapid thermal gelation at 37°C
• Bind strongly to bile salts

Correct Answer: Are degraded by colonic bacterial enzymes

Q18. Polymeric micelles suitable for solubilizing hydrophobic drugs are commonly formed from:

• PEG–PLA or PEG–PCL amphiphilic block copolymers
• Crosslinked alginate networks
• High-MW HPMC homopolymers
• Pure PLA homopolymers without PEG

Correct Answer: PEG–PLA or PEG–PCL amphiphilic block copolymers

Q19. A polymer that can be ionically crosslinked under mild, aqueous, protein-friendly conditions is:

• Poly(methyl methacrylate)
• Sodium alginate (with Ca2+)
• Polycaprolactone
• Polyanhydride

Correct Answer: Sodium alginate (with Ca2+)

Q20. Which biodegradable polymers are widely used and FDA-approved in marketed parenteral long-acting depot formulations?

• PLGA and PLA
• PCL and PNIPAM
• Chitosan and hyaluronic acid
• Eudragit L and S

Correct Answer: PLGA and PLA

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