Evaluation of buccal DDS MCQs With Answer

Evaluation of Buccal DDS MCQs With Answer

Buccal drug delivery systems (DDS) are designed to deliver therapeutics across the oral mucosa, offering advantages like avoidance of first-pass metabolism, rapid onset, and improved patient compliance. For M. Pharm students, understanding evaluation techniques is critical for rational design and optimization of buccal films, patches, gels, and tablets. This MCQ set focuses on essential assessments: mucoadhesive strength (tensile and shear), in vitro residence time, swelling and surface pH, mechanical characterization, in vitro release and kinetic modeling, ex vivo permeation through suitable tissues, histopathology, and in vivo pharmacokinetics. You’ll also revisit analytical tools (DSC, FTIR), formulation-excipient compatibility, and simulated saliva considerations. Practice these questions to strengthen your conceptual depth and experimental reasoning in buccal DDS evaluation.

Q1. Which method is most appropriate to quantify the mucoadhesive strength of buccal films under tensile detachment?

• Texture analyzer-based detachment test using excised buccal mucosa
• USP II dissolution apparatus
• Differential scanning calorimetry
• UV–Visible spectrophotometry

Correct Answer: Texture analyzer-based detachment test using excised buccal mucosa

Q2. The most widely accepted ex vivo tissue model for buccal permeation studies due to its similarity to human mucosa is:

• Porcine buccal mucosa
• Rat ileum
• Rabbit cornea
• Chick chorioallantoic membrane

Correct Answer: Porcine buccal mucosa

Q3. In vitro residence time of buccal films is commonly evaluated using which setup?

• Modified USP disintegration apparatus with mucin-coated substrate or buccal tissue
• Polarimeter
• Gas chromatograph
• Coulter counter

Correct Answer: Modified USP disintegration apparatus with mucin-coated substrate or buccal tissue

Q4. Surface pH of a buccal film is best measured by:

• Placing a moistened flat pH microelectrode directly on the hydrated film surface
• Universal indicator paper dipped in dry film
• X-ray diffractometry
• Potentiometric titration with NaOH

Correct Answer: Placing a moistened flat pH microelectrode directly on the hydrated film surface

Q5. Swelling index of a buccal film is typically calculated as:

• Percentage increase in weight: (Wt − W0)/W0 × 100 after hydration
• Decrease in thickness over time: (T0 − Tt)/T0 × 100
• Change in melting point before/after hydration
• Increase in UV absorbance with time

Correct Answer: Percentage increase in weight: (Wt − W0)/W0 × 100 after hydration

Q6. Which release kinetics model is most indicative of diffusion-controlled drug release from thin buccal films?

• Higuchi model
• Michaelis–Menten model
• Hixson–Crowell model
• Zero-order model exclusively

Correct Answer: Higuchi model

Q7. According to the Korsmeyer–Peppas model for slab geometry, an exponent n ≈ 0.5 suggests:

• Fickian diffusion-controlled release
• Case II transport (polymer relaxation-controlled)
• Zero-order release dominated by erosion
• Super Case II transport

Correct Answer: Fickian diffusion-controlled release

Q8. To minimize mucosal irritation, the surface pH of a buccal dosage form should be close to:

• Salivary pH (approximately neutral)
• Gastric pH (1–2)
• Strictly 7.4 to match blood pH
• Alkaline pH > 9

Correct Answer: Salivary pH (approximately neutral)

Q9. Which analytical technique best detects solid-state drug–polymer interaction via changes in melting endotherm?

• Differential scanning calorimetry (DSC)
• UV–Visible spectrophotometry
• HPLC assay of content uniformity
• Gas chromatography–mass spectrometry

Correct Answer: Differential scanning calorimetry (DSC)

Q10. During ex vivo permeation using a Franz diffusion cell, the receptor compartment is typically maintained at:

• 37 ± 0.5 °C with continuous stirring
• 25 °C without stirring
• 50 °C with intermittent stirring
• 4 °C to suppress tissue metabolism

Correct Answer: 37 ± 0.5 °C with continuous stirring

Q11. Which setup is used to quantify mucoadhesion under shear conditions?

• Parallel-plate method measuring detachment under lateral (shear) force
• Sessile drop contact angle goniometry
• Spray-drying cyclone separator
• Electron spin resonance spectroscopy

Correct Answer: Parallel-plate method measuring detachment under lateral (shear) force

Q12. The primary purpose of a saliva wash-off test in buccal DDS evaluation is to assess:

• Retention of the dosage form under simulated salivary flow
• Drug crystallinity in the film
• Particle morphology by microscopy
• Zeta potential of dispersed droplets

Correct Answer: Retention of the dosage form under simulated salivary flow

Q13. The most appropriate approach to assess dose uniformity across a reservoir-type buccal patch is:

• Content uniformity by assaying multiple punched sections from different locations
• Visual inspection for color uniformity
• Friability test using a Roche friabilator
• Tap density measurement

Correct Answer: Content uniformity by assaying multiple punched sections from different locations

Q14. The primary mechanism contributing to mucoadhesion of polyacrylic acid derivatives to buccal mucosa is:

• Hydrogen bonding and interpenetration with mucin glycoproteins
• Covalent bonding to tooth enamel
• Ionic bonding to dentin
• Exclusive van der Waals interactions

Correct Answer: Hydrogen bonding and interpenetration with mucin glycoproteins

Q15. Which parameter best reflects the intrinsic permeability of buccal tissue independent of donor concentration?

• Apparent permeability coefficient (Papp)
• Cmax from plasma
• tmax from plasma
• Area under the curve (AUC)

Correct Answer: Apparent permeability coefficient (Papp)

Q16. Which technique directly evaluates tissue integrity and potential irritation after ex vivo exposure to a buccal formulation?

• Histopathology with hematoxylin and eosin (H&E) staining
• X-ray powder diffraction
• Nuclear magnetic resonance
• Atomic force microscopy of film surface

Correct Answer: Histopathology with hematoxylin and eosin (H&E) staining

Q17. Simulated saliva used in evaluation of buccal DDS is commonly buffered with:

• Phosphate buffer to approximate salivary pH and ionic strength
• Strong hydrochloric acid to pH 1.2
• Borate buffer at pH 9.5
• Pure distilled water without electrolytes

Correct Answer: Phosphate buffer to approximate salivary pH and ionic strength

Q18. Which mechanical parameter is most informative about the flexibility and crack resistance of buccal films?

• Folding endurance
• Friability
• Carr’s index
• Angle of repose

Correct Answer: Folding endurance

Q19. Contact angle measurements on buccal films primarily inform about:

• Wettability and surface energy influencing hydration and mucoadhesion
• Molecular weight of the polymer
• Drug potency
• Particle size distribution

Correct Answer: Wettability and surface energy influencing hydration and mucoadhesion

Q20. Which in vivo outcome most convincingly demonstrates improved systemic delivery via the buccal route compared to oral swallowing?

• Relative bioavailability (AUC ratio) compared to oral reference
• Reduction in particle size of the film
• Increased crystallinity by XRD
• Change in zeta potential of the formulation

Correct Answer: Relative bioavailability (AUC ratio) compared to oral reference

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