Monophasic liquids – Nasal drops MCQs With Answer

Introduction

Monophasic liquids for nasal administration are clear, single-phase solutions designed for intranasal delivery where rapid onset, local action, or systemic absorption is desired. For B. Pharm students, mastering nasal drops involves understanding formulation parameters like pH (typically 4.5–6.5), isotonicity (≈0.9% NaCl), osmolality, sterility, preservatives, buffers, and viscosity modifiers. Key excipients include mucoadhesives (HPMC, carbopol), humectants (glycerin), solubilizers (PEG 400, cyclodextrins), antioxidants (ascorbic acid), and chelators (EDTA). Critical quality attributes span antimicrobial effectiveness, content assay, stability, container–closure selection, and patient comfort. The nasal route offers first-pass avoidance and potential nose-to-brain delivery via olfactory/trigeminal pathways. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which statement best defines monophasic nasal drops?

• A true solution intended for intranasal instillation, free of dispersed solids or oils
• A coarse suspension meant for nasal sprays
• An emulsion designed for pulmonary delivery
• A semisolid gel for topical dermal application

Correct Answer: A true solution intended for intranasal instillation, free of dispersed solids or oils

Q2. What is the typical target pH range for nasal drop formulations to minimize irritation?

• 4.5–6.5
• 1.0–2.0
• 7.5–9.0
• 10.0–12.0

Correct Answer: 4.5–6.5

Q3. Isotonic nasal solutions are usually adjusted to be equivalent to which of the following?

• 0.9% w/v sodium chloride (≈308 mOsm/kg)
• 0.45% w/v sodium chloride
• 5% w/v dextrose only
• No isotonicity requirement for nasal drops

Correct Answer: 0.9% w/v sodium chloride (≈308 mOsm/kg)

Q4. Which excipient is primarily used to impart mucoadhesion and increase nasal residence time?

• Carbopol (carbomer)
• Sodium chloride
• Talc
• Lactose monohydrate

Correct Answer: Carbopol (carbomer)

Q5. Which preservative is commonly used in nasal drops but is associated with potential ciliary toxicity at higher levels?

• Benzalkonium chloride
• Sodium benzoate
• Potassium sorbate
• Phenoxyethanol

Correct Answer: Benzalkonium chloride

Q6. Which buffer system is most commonly preferred for nasal drop formulations near pH 5–6?

• Phosphate buffer
• Borate buffer
• Carbonate/bicarbonate buffer
• Tris buffer

Correct Answer: Phosphate buffer

Q7. What is a typical delivered volume per drop from a standard aqueous nasal dropper?

• 25 µL
• 50 µL
• 100 µL
• 1,000 µL

Correct Answer: 50 µL

Q8. What is a commonly accepted comfortable liquid dose volume per nostril for nasal drops/sprays?

• 100 µL
• 5 mL
• 1,000 µL
• 10 µL

Correct Answer: 100 µL

Q9. Which combination helps protect oxidation-sensitive drugs in nasal solutions?

• Ascorbic acid with disodium EDTA
• Sodium chloride with glycerin
• HPMC with carbopol
• Polysorbate 80 with PEG 400

Correct Answer: Ascorbic acid with disodium EDTA

Q10. Which solubilizer can improve the aqueous solubility of lipophilic drugs in nasal drops?

• Hydroxypropyl-β-cyclodextrin
• Talc
• Microcrystalline cellulose
• Maize starch

Correct Answer: Hydroxypropyl-β-cyclodextrin

Q11. What is the general microbiological quality requirement for multidose nasal drops?

• Sterile product with an effective preservative system
• Non-sterile but preserved
• Non-sterile and unpreserved
• Sterile but without preservative

Correct Answer: Sterile product with an effective preservative system

Q12. A nasal drop labeled 0.05% w/v oxymetazoline contains how many mg/mL?

• 0.05 mg/mL
• 0.5 mg/mL
• 5 mg/mL
• 50 mg/mL

Correct Answer: 0.5 mg/mL

Q13. Why are viscosity enhancers like HPMC added to nasal drops?

• To increase residence time by reducing drainage
• To sweeten the formulation
• To sterilize the solution
• To neutralize acids

Correct Answer: To increase residence time by reducing drainage

Q14. Which factor most directly increases passive transcellular absorption through the nasal epithelium?

• Higher unionized fraction and lipophilicity
• Darker solution color
• Use of a glass dropper
• Large font size on the label

Correct Answer: Higher unionized fraction and lipophilicity

Q15. Which is a key advantage of the nasal route for systemic delivery?

• Bypasses hepatic first-pass metabolism
• Allows very high dose volumes
• Eliminates mucociliary clearance
• Is unaffected by formulation pH

Correct Answer: Bypasses hepatic first-pass metabolism

Q16. What osmolality range is generally targeted to minimize nasal irritation?

• 50–100 mOsm/kg
• 150–200 mOsm/kg
• Approximately 280–320 mOsm/kg
• Greater than 600 mOsm/kg

Correct Answer: Approximately 280–320 mOsm/kg

Q17. Which preservative should be avoided in neonatal nasal drops due to toxicity concerns?

• Benzyl alcohol
• Phenoxyethanol
• Sodium benzoate
• Potassium sorbate

Correct Answer: Benzyl alcohol

Q18. What is the primary role of humectants like glycerin in nasal drops?

• To reduce drying and improve comfort
• To act as the main buffer
• To provide broad-spectrum antimicrobial activity
• To cause significant hypertonicity

Correct Answer: To reduce drying and improve comfort

Q19. Which container–closure is most appropriate for multidose nasal drops?

• LDPE squeeze bottle with integrated dropper tip
• Open glass beaker
• Metal tin with lid
• Blister pack for tablets

Correct Answer: LDPE squeeze bottle with integrated dropper tip

Q20. Which compendial test evaluates the effectiveness of preservatives in nasal drops?

• USP <51> Antimicrobial Effectiveness Test
• USP <71> Sterility Tests
• USP <85> Bacterial Endotoxins Test
• USP <905> Uniformity of Dosage Units

Correct Answer: USP <51> Antimicrobial Effectiveness Test

Q21. Why should surfactant levels (e.g., polysorbate 80) be minimized in nasal drops?

• High levels may disrupt ciliary function and increase irritation
• They always increase viscosity excessively
• They reduce drug solubility
• They inactivate buffers

Correct Answer: High levels may disrupt ciliary function and increase irritation

Q22. Which analytical approach is typically used to confirm drug content in nasal solutions?

• Assay by HPLC against a validated standard
• Karl Fischer moisture determination
• BET surface area measurement
• Tablet friability testing

Correct Answer: Assay by HPLC against a validated standard

Q23. How is isotonicity commonly adjusted in nasal formulations?

• By adding sodium chloride based on NaCl equivalent (E-value) calculations
• By adding talc
• By increasing the pH to alkaline levels
• By adding starch syrup

Correct Answer: By adding sodium chloride based on NaCl equivalent (E-value) calculations

Q24. Which polymer is cationic and can transiently open tight junctions to enhance nasal absorption?

• Chitosan
• HPMC
• PVP
• PEG 400

Correct Answer: Chitosan

Q25. Which labeling statement is essential for nasal drop products?

• For intranasal use only
• For intravenous use
• For otic use only
• For dermal use only

Correct Answer: For intranasal use only

Q26. A patient reports burning on instillation despite isotonicity. What is the most likely cause?

• Formulation pH outside the comfortable nasal range
• Excessively low viscosity
• Too low dose volume
• Absence of colorant

Correct Answer: Formulation pH outside the comfortable nasal range

Q27. Loss of preservative efficacy of benzalkonium chloride during storage is most likely due to:

• Adsorption to plastic or rubber components
• Freeze-drying of the solution
• Sublimation at room temperature
• Infrared photolysis

Correct Answer: Adsorption to plastic or rubber components

Q28. What is the typical mucociliary clearance half-time in the nasal cavity?

• 1–2 minutes
• 5–10 minutes
• 15–20 minutes
• 2–3 hours

Correct Answer: 15–20 minutes

Q29. Which pathways enable potential nose-to-brain delivery from nasal drops?

• Olfactory and trigeminal neuronal pathways
• Portal venous pathway
• Pulmonary alveolar pathway
• Lymphatic thoracic duct only

Correct Answer: Olfactory and trigeminal neuronal pathways

Q30. A drug at 1% w/v has an NaCl equivalent (E) of 0.2. How much NaCl should be added to make the solution isotonic (0.9% w/v), assuming no other contributors?

• 0.7% w/v NaCl
• 0.9% w/v NaCl
• 0.8% w/v NaCl
• 0.68% w/v NaCl

Correct Answer: 0.7% w/v NaCl

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