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Questions and Answers
What is a primary function of the nasal cavity?
What is a primary function of the nasal cavity?
Which anatomical structures are crucial for intranasal drug delivery?
Which anatomical structures are crucial for intranasal drug delivery?
What is the main role of the vestibular region of the nasal cavity?
What is the main role of the vestibular region of the nasal cavity?
Which turbinate primarily communicates with several sinuses?
Which turbinate primarily communicates with several sinuses?
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What characteristic of the olfactory region affects drug delivery to the brain?
What characteristic of the olfactory region affects drug delivery to the brain?
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Which function is associated with the respiratory region of the nasal cavity?
Which function is associated with the respiratory region of the nasal cavity?
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Which of the following has less physiological significance among the turbinates?
Which of the following has less physiological significance among the turbinates?
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What is a systemic delivery example that can be administered through the nasal cavity?
What is a systemic delivery example that can be administered through the nasal cavity?
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What is the primary role of cilia in the nasal cavity?
What is the primary role of cilia in the nasal cavity?
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Which type of epithelium is NOT found in the anterior one-third of the respiratory region?
Which type of epithelium is NOT found in the anterior one-third of the respiratory region?
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What factor can slow down ciliary movement and mucociliary clearance?
What factor can slow down ciliary movement and mucociliary clearance?
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What is a significant advantage of intranasal drug delivery?
What is a significant advantage of intranasal drug delivery?
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Why is the nasal epithelium well-suited for drug absorption?
Why is the nasal epithelium well-suited for drug absorption?
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What is the average pH of mucus in the nasal cavity?
What is the average pH of mucus in the nasal cavity?
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What role do goblet cells play in the nasal mucosa?
What role do goblet cells play in the nasal mucosa?
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What is the impact of the absence of a hepatic portal system on drugs absorbed through the nasal cavity?
What is the impact of the absence of a hepatic portal system on drugs absorbed through the nasal cavity?
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What is the particle size range necessary to prevent bypassing the nasal cavity?
What is the particle size range necessary to prevent bypassing the nasal cavity?
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Which statement about nasal spray priming is correct?
Which statement about nasal spray priming is correct?
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Which of the following nasal sprays is known to be a bitter-tasting decongestant?
Which of the following nasal sprays is known to be a bitter-tasting decongestant?
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What is generally true about the administration of nasal sprays?
What is generally true about the administration of nasal sprays?
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Which nasal spray is used as an opioid overdose treatment and does not require priming?
Which nasal spray is used as an opioid overdose treatment and does not require priming?
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What is a potential disadvantage of using intranasal drug delivery?
What is a potential disadvantage of using intranasal drug delivery?
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Which pre-existing nasal condition is NOT mentioned as a complication affecting drug deposition?
Which pre-existing nasal condition is NOT mentioned as a complication affecting drug deposition?
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What pH range is advisable to minimize damage to the mucociliary apparatus?
What pH range is advisable to minimize damage to the mucociliary apparatus?
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How does viscosity impact intranasal drug delivery?
How does viscosity impact intranasal drug delivery?
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What is the effect of environmental factors like humidity on intranasal drug delivery?
What is the effect of environmental factors like humidity on intranasal drug delivery?
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What is a common preservative used in nasal drops and sprays?
What is a common preservative used in nasal drops and sprays?
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How do metered dose sprays work in intranasal drug delivery?
How do metered dose sprays work in intranasal drug delivery?
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Which type of intranasal product generally provides greater coverage throughout the nasal cavity?
Which type of intranasal product generally provides greater coverage throughout the nasal cavity?
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Study Notes
Intranasal Drug Delivery
- Two main approaches: nasal cavity and lungs (pulmonary)
- Nasal cavity is a promising route for drug administration, suitable for local or systemic use.
- Examples of local delivery: nasal decongestants, glucocorticoids (e.g., Flonase)
- Examples of systemic delivery: Vitamin B12, pain medications
Anatomy and Physiology of the Nose
- Nose functions for olfaction (smelling) and conditioning inspired air.
- Nasal cavity turbinates are important for intranasal drug delivery.
Regions of the Nasal Cavity
- Three regions: vestibular, respiratory, olfactory
- Vestibular Region: filters and baffles air, lined with hairs and pseudostratified epithelium, nasal valve.
- Respiratory Region: consists of three turbinates (inferior, middle, superior), functions in directing, heating, and humidifying air, increasing surface area for aerosol deposition and drug absorption. Inferior turbinate connects with nasal lacrimal ducts, middle with sinuses, and superior with less significance.
- Olfactory Region: located above the respiratory region; thin layer is between the brain and the olfactory region; small surface area.
Nasal Mucosa
- Respiratory Region Epithelium: anterior one-third has various epithelial types (squamous, transitional, pseudostratified columnar), posterior two-thirds are ciliated pseudostratified columnar epithelia with goblet cells producing mucus.
- Mucociliary Clearance: cilia sweep mucus and trapped substances, promoting drug removal, crucial for undissolved drugs. Mucus viscosity affects the clearance rate, significant factor for drug absorption.
- Mucus functions in protection, hydration, trapping airborne materials, and transport.
Blood Supply
- Nasal epithelium is highly vascularized with fenestrated capillaries.
- Drugs can easily enter the bloodstream.
- No hepatic first-pass effect.
Advantages of Intranasal Drug Delivery
- Avoidance of GI acid and enzymatic degradation
- No hepatic first-pass effect.
- Potential for high absorption rates.
- Absorption of large molecules (peptides)
- Immunity to other mucous membranes.
Disadvantages of Intranasal Drug Delivery
- Increased intranasal metabolism.
- Potential complications from pre-existing nasal conditions (e.g., rhinitis, hay fever, asthma, nasal polyps).
Considerations for Product Design
- pH: solutions with pH 4-8 minimize damage to mucociliary apparatus, best maintained around 7-10, buffer capacity is important.
- Osmolarity: isotonic fluids are preferred to minimize irritation in nasal sprays.
- Viscosity: high viscosity can slow mucociliary clearance, increasing residence time, but excessive viscosity hinders drug release, use viscosity-enhancing excipients in suspensions.
- Preservation: antimicrobial preservatives are essential for repeated use products, Benzalkonium chloride is a common preservative but potential toxicity should be considered.
Drug Deposition
- Sprays are primarily deposited in the anterior region of the nasal cavity, while drops provide broader coverage but are cleared more rapidly.
- Sprays are primarily measured dose or single-dose sprays.
- Particle size is critical.
Product Examples (briefly listed here)
- Diazlasine (Afrin): nasal decongestant.
- Corticosteroids: suspensions with surfactants.
- Narcan: single-use.
- Migraine medications: single-dose.
- Nascobal: systemic vitamin B12 deficiency medication, single-day.
- Flumist: single-use vaccine.
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Description
Explore the fascinating world of intranasal drug delivery, focusing on the anatomy and physiology of the nose. This quiz delves into the regions of the nasal cavity and their significance in both local and systemic drug administration. Learn about specific examples, functions, and structures involved in effective drug delivery through the nasal route.
