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Questions and Answers
Questions and Answers
Which of the following is NOT a primary region of the nasal cavity?
Which of the following is NOT a primary region of the nasal cavity?
- Gastric region (correct)
- Nasal vestibule
- Respiratory region
- Olfactory region
The pH of nasal secretion in adults typically ranges from 7.0 to 8.0.
The pH of nasal secretion in adults typically ranges from 7.0 to 8.0.
False (B)
What is the approximate depth, in centimeters, of the nasal cavity passage?
What is the approximate depth, in centimeters, of the nasal cavity passage?
12-14
Nasal secretions are primarily composed of water, accounting for approximately ______% of their composition.
Nasal secretions are primarily composed of water, accounting for approximately ______% of their composition.
What is a primary function of the nose related to air intake?
What is a primary function of the nose related to air intake?
Nasal drug delivery completely avoids first-pass metabolism.
Nasal drug delivery completely avoids first-pass metabolism.
What term describes the relatively rapid removal process of large particles trapped in the nasal filter, compared to the bronchi and alveoli?
What term describes the relatively rapid removal process of large particles trapped in the nasal filter, compared to the bronchi and alveoli?
One of the main disadvantages of some nasal drug delivery systems is the potential for nasal ________.
One of the main disadvantages of some nasal drug delivery systems is the potential for nasal ________.
Which particle size is considered respirable and likely to deposit within the lung following nasal administration?
Which particle size is considered respirable and likely to deposit within the lung following nasal administration?
Most drugs administered nasally are absorbed via active transport mechanisms.
Most drugs administered nasally are absorbed via active transport mechanisms.
Absorption of a drug via the nasal route is highly dependent on what property of the drug?
Absorption of a drug via the nasal route is highly dependent on what property of the drug?
To maintain ciliary function, nasal formulations must be formulated to be _________.
To maintain ciliary function, nasal formulations must be formulated to be _________.
Which of the following enzymes is found within the nasal cavity's enzymatic barrier?
Which of the following enzymes is found within the nasal cavity's enzymatic barrier?
Flavors are never added to nasal formulations due to the risk of irritation.
Flavors are never added to nasal formulations due to the risk of irritation.
Name two viscosity-modifying agents which are often included as excipients in nasal formulations.
Name two viscosity-modifying agents which are often included as excipients in nasal formulations.
Besides parabens and phenyl alcohol, __________ ___________ is another commonly used preservative found in nasal formulations
Besides parabens and phenyl alcohol, __________ ___________ is another commonly used preservative found in nasal formulations
What is the primary purpose of including penetration enhancers in nasal drug formulations?
What is the primary purpose of including penetration enhancers in nasal drug formulations?
Nasal gels are known for excellent spreading over the nasal mucosa due to their low viscosity.
Nasal gels are known for excellent spreading over the nasal mucosa due to their low viscosity.
Give an example of a benefit of using nasal gels in the drug delivery
Give an example of a benefit of using nasal gels in the drug delivery
Irritation and __________ are recognized disadvantages often linked with nasal powders because of their dry dosage form.
Irritation and __________ are recognized disadvantages often linked with nasal powders because of their dry dosage form.
Match the following nasal drug delivery methods with their characteristics.
Match the following nasal drug delivery methods with their characteristics.
Which one of these is a characteristic related to nasal drops?
Which one of these is a characteristic related to nasal drops?
Nasal sprays can only be formulated into suspension solutions.
Nasal sprays can only be formulated into suspension solutions.
Explain the statement: Nasal drops main disadvantage is the lack of the dose precision
Explain the statement: Nasal drops main disadvantage is the lack of the dose precision
Solution formulations are commonly administered with actuators that can deliver actuation volumes as low as ______ µl
Solution formulations are commonly administered with actuators that can deliver actuation volumes as low as ______ µl
Which of the following statements is correct about viscous nasal gels?
Which of the following statements is correct about viscous nasal gels?
Powder formulations are used when the drug exhibits a high solution stability.
Powder formulations are used when the drug exhibits a high solution stability.
Explain why the drug absorption may be an issue when using nasal powders
Explain why the drug absorption may be an issue when using nasal powders
Emulsions and ointments are commonly selected when the intent is to incorporate a ______ compound into a formulation
Emulsions and ointments are commonly selected when the intent is to incorporate a ______ compound into a formulation
What is the primary function of the blood–brain barrier (BBB)?
What is the primary function of the blood–brain barrier (BBB)?
The blood-brain barrier (BBB) allows any drug to easily pass into the brain.
The blood-brain barrier (BBB) allows any drug to easily pass into the brain.
How does intranasal delivery bypass the blood-brain barrier?
How does intranasal delivery bypass the blood-brain barrier?
The unique connections that the ______ and ______ nerves provide between the brain and external environment, allows intranasal delivery to provide a practical, non-invasive method of bypassing the blood-brain barrier.
The unique connections that the ______ and ______ nerves provide between the brain and external environment, allows intranasal delivery to provide a practical, non-invasive method of bypassing the blood-brain barrier.
What condition may be potentially be treated with levodopa through nasal delivery?
What condition may be potentially be treated with levodopa through nasal delivery?
Nasal drug delivery can improve bioavailability of small drug molecules.
Nasal drug delivery can improve bioavailability of small drug molecules.
What are the benefits of nasal administration?
What are the benefits of nasal administration?
Drugs adminsitered nasally can pass through the ______ or ______ route.
Drugs adminsitered nasally can pass through the ______ or ______ route.
The lateral walls of the nasal cavity includes a folded structure which enlarges the surface area in the nose to about:
The lateral walls of the nasal cavity includes a folded structure which enlarges the surface area in the nose to about:
Composition of nasal secretions is 50% water.
Composition of nasal secretions is 50% water.
State the size of the actuation delivered by desmopressin nasal spray.
State the size of the actuation delivered by desmopressin nasal spray.
Why are nasal formulations often designed to be isotonic?
Why are nasal formulations often designed to be isotonic?
Nasal drug delivery is suitable only for local administration and cannot be used for systemic drug delivery.
Nasal drug delivery is suitable only for local administration and cannot be used for systemic drug delivery.
What is a primary disadvantage of using nasal drops compared to nasal sprays for drug delivery?
What is a primary disadvantage of using nasal drops compared to nasal sprays for drug delivery?
Large particles trapped in the nasal filter undergo a relatively ______ clearance compared to the bronchi and alveoli.
Large particles trapped in the nasal filter undergo a relatively ______ clearance compared to the bronchi and alveoli.
Match the following nasal drug delivery barriers with their descriptions:
Match the following nasal drug delivery barriers with their descriptions:
Questions and Answers
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Flashcards
Flashcards
Nasal Drug Delivery Routes
Nasal Drug Delivery Routes
Nasal drug delivery is used for local and systemic administration of drugs.
Depth of Nasal Cavity
Depth of Nasal Cavity
The nasal cavity consists of a passage approximately 12-14 cm in depth.
Nasal Cavity Regions
Nasal Cavity Regions
The main regions are the nasal vestibule, respiratory, and olfactory regions.
Nasal Cavity Lining
Nasal Cavity Lining
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Nasal Cavity Surface Area
Nasal Cavity Surface Area
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Source of Nasal Secretions
Source of Nasal Secretions
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pH of Nasal Secretion
pH of Nasal Secretion
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Epithelium cell types
Epithelium cell types
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Nasal Secretion Composition
Nasal Secretion Composition
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Nasal Enzymes
Nasal Enzymes
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Nasal Blood Supply
Nasal Blood Supply
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Nose Functions
Nose Functions
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Particle Clearance
Particle Clearance
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Nasal Delivery Advantages
Nasal Delivery Advantages
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Nasal Delivery Disadvantages
Nasal Delivery Disadvantages
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Physical Barrier of Drug Absorption
Physical Barrier of Drug Absorption
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Drug Passage Routes
Drug Passage Routes
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A phisical barrier
A phisical barrier
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Particle Size Effect
Particle Size Effect
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Good Nasal Absorption Location
Good Nasal Absorption Location
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Drug Absorption Method
Drug Absorption Method
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Drug absorbtion factor
Drug absorbtion factor
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Strong Enzymatic Barrier
Strong Enzymatic Barrier
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Nasal Formulations pH
Nasal Formulations pH
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Nasal Formulations Tonicity
Nasal Formulations Tonicity
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Purpose of Flavors/Sweeteners
Purpose of Flavors/Sweeteners
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Viscosity Modifying Agents
Viscosity Modifying Agents
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Solubilizers examples
Solubilizers examples
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Preservative Examples
Preservative Examples
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Antioxidant Examples
Antioxidant Examples
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Penetration enhancer example
Penetration enhancer example
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Nasal Drops
Nasal Drops
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Nasal Sprays
Nasal Sprays
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Nasal Gels
Nasal Gels
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Nasal Powders
Nasal Powders
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Emulsion and Ointment use
Emulsion and Ointment use
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Blood Brain Barrier (BBB)
Blood Brain Barrier (BBB)
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Intranasal Delivery
Intranasal Delivery
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Crossing BBB
Crossing BBB
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Route to Brain
Route to Brain
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Potential application
Potential application
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Flashcards
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Study Notes
Study Notes
- Nasal drug delivery involves administering drugs through the nasal route for local or systemic effects.
Objectives
- List advantages and disadvantages of nasal drug delivery
- List formulation selection considerations
- Describe excipients used in nasal formulations
- List various formulation types for nasal delivery
Anatomy of the Nose
- The nasal cavity is approximately 12-14 cm deep.
- The nasal cavity includes the nasal vestibule, respiratory, and olfactory regions.
- The nasal lining is ciliated, highly vascular, and rich in mucus.
- The lateral walls of the nasal cavity have a folded structure, increasing the surface area to about 150 cm².
- Nasal secretions are produced by goblet cells, nasal glands, and transudate from plasma.
- The pH of nasal secretions is 5.5-6.5 in adults and 5.0-6.7 in infants.
- Nasal secretions are composed of 95% water, 1-2% salt, and 2-3% mucin, with trace amounts of Na, K, Ca, and albumin.
- Nasal secretions contain enzymes such as monooxygenase, lactate dehydrogenase, oxidoreductase, phosphates, hydrolases, and esterases.
- Blood flow through external and internal carotid arteries provides blood to the nasal cavity.
- The nose warms and humidifies air and filters environmental pollutants.
- The respiratory epithelium has four basic cells including: nonciliated columnar cells, goblet cells, basal cells, and ciliated columnar cells.
- The respiratory epithelium is covered by a two-component mucus layer.
- The mucus layer has a bottom layer of low viscosity sol surrounding the cilia and microvilli.
- The mucus layer has a viscous and bioadhesive gel layer on the surface.
- Large particles trapped in the nasal filter undergo relatively rapid clearance, in minutes compared to hours or weeks for the bronchi and alveoli, respectively.
Advantages of Nasal Delivery
- Large mucosal surface area for dose absorption
- Rapid drug absorption due to highly vascularized surfaces
- Rapid onset of action
- Ease of administration and non-invasive.
- Avoidance of the gastrointestinal tract and first-pass metabolism
- Improved bioavailability
- The bioavailability of larger drug molecules can be improved with absorption enhancers or other approaches
- Improved convenience and compliance
- Self-administration
- Potential to bypass the blood-brain barrier
Disadvantages of Nasal Delivery
- Absorption enhancers used to improve nasal drug delivery may have undetermined histological toxicity
- Smaller absorption surface area compared to the GI tract
- Drug removal is impossible once administered
- Possible nasal irritation makes it relatively inconvenient for patients when compared to oral delivery
Barriers to Drug Absorption in Nasal Delivery
- A physical barrier is composed of mucus and the epithelium
- Nasally administered drugs must pass through the epithelial cell layer to reach the systemic circulation.
- Drug passage through this barrier occurs via the transcellular or paracellular route.
- The nasal mucosa is a relatively ineffective structural barrier due to low membrane resistance and high permeability.
- Mucociliary clearance removes substances from the nasal cavity.
- An enzymatic barrier exists in the nasal cavity.
Particle Size Considerations
- Particles larger than 10 µm do not penetrate the pulmonary airways and deposit at impaction sites in the upper respiratory tract or are exhaled.
- Particles between 5-10 µm are considered respirable and deposit within the lung.
- Particles smaller than 1 µm are inhaled deeply into the pulmonary airways but undergo minimal gravitational settling and are likely exhaled during normal tidal breathing.
- Effective nasal absorption requires dosing above the nasal palate level.
- The anterior area of the outer nasal cavity shows minimal or poor absorption.
Formulation Selection Considerations
- The majority of drugs absorb through passive diffusion
- Some drugs are absorbed by active transport, such as amino acids
- Drugs with a molecular weight of up to 500 daltons are easily absorbed without penetration enhancers
- Absorption depends on the lipophilicity of the drug.
- Nasal cavity volume is ~20 ml, and typical administration is ~200 µl, requiring highly water-soluble drugs for therapeutic dosing
Drug Stability
- The nasal cavity has a strong enzymatic barrier including: aldehyde dehydrogenase, glutathione transferase, carboxylesterases, and cytochrome P-450 dependent mono-oxygenases
- Although enzymatic levels are significantly lower than in the liver
pH
- Nasal formulations are generally buffered within the pH range of 5.5-6.5.
- Nasal absorption of weak electrolytes is highly dependent on the degree of ionization.
- Higher nasal absorption is achieved at a pH lower than the pKa.
- Nonionized lipophilic forms cross the nasal epithelial barriers via the transcellular route
- Hydrophilic ionized forms pass through the aqueous paracellular route.
Isotonicity
- Nasal formulations are formulated to be isotonic to maintain ciliary function.
Selection of Excipients
- A limited range of excipients are used and approved by regulatory authorities.
- Excipients should be either ionic (saline) or nonionic (dextrose) for tonicity.
- Counter-ion effects may influence pH adjustment and buffer selection
- Flavors or sweetening agents are added to mask taste
Types of Excipients
- Viscosity Modifying Agents: Carbopol, cellulose derivatives, starch, dextran, chitosan increase viscosity and provide prolonged retention.
- Solubilizers: Surfactants, glycerin, and water-miscible solvents (ethanol) enhance solubility.
- Preservatives: Parabens, benzalkonium chloride, and phenyl alcohol prevent microbial growth.
- Antioxidants: Sodium bisulphite, butylated hydroxytoluene, and vitamins (C or D) prevent oxidation.
- Penetration Enhancers: Oleic acid, lauric acid, phospholipids, and surfactants enhance drug absorption.
- Penetration enhancers should increase drug absorption without damaging the tissue or causing irritation.
Various Dosage Forms
- Nasal Drops: Simple and convenient but lack dose precision.
- Solution Sprays: Metered dose pumps and actuators can deliver precise doses, from 25 to 200 μl.
- Nasal Gels: High-viscosity thickened solutions or suspensions reduce post-nasal drip, taste impact from swallowing, leakage, and irritation by using emollient.
- Nasal Powders: Suitable for drugs with poor solution stability where drug absorption depends on solubility and diffusion.
- Emulsions and Ointments: Incorporate hydrophobic compounds into a hydrophilic continuous phase where the oil phase may enhance drug absorption.
Devices for Nasal Delivery
- AccuSpray: A system that provides single or bi-dose delivery in 50-250µL
- Nasal pumps, screw top, crimp or snap-on: Provides multidose preserved system with 45, 50, 70, or 90 µL
- Bidose: A preservative-free system with 2 × 100 µL delivery
Blood-Brain Barrier (BBB) and Intranasal Delivery
- The BBB is a highly selective semipermeable border of endothelial cells.
- It prevents solutes in the circulating blood from non-selectively crossing into the extracellular fluid of the central nervous system.
- Intranasal delivery is a practical, non-invasive method of bypassing the BBB.
- This approach can deliver therapeutic agents to the brain and spinal cord.
- The technology allows drugs that do not cross the BBB to be delivered to the central nervous system in minutes.
- It directly delivers drugs that do cross the BBB to the brain, reducing systemic administration and its potential side effects.
- This is possible due to unique connections that olfactory and trigeminal nerves have between the brain and the external environment.
- Potential Applications: Include Levodopa for Parkinson's disease, Alzheimer's disease, and Neuronal degeneration treatments
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