Nasal drug delivery Flashcards

1
Q

nasal drug delivery is the fastest growing drug delivery system, true or false

A

true

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2
Q

the nasal cavity extends from where to where

A

the nostrils to the nasopharynx

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3
Q

the nasal cavity is a poorly vascularised system, rich in secretory cells, true or false

A

false
it is a** highly ** vascularised system, rich in secretory cells

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4
Q

which region of the nasal cavity is located at it’s roof

A

the olfactory region

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5
Q

name some types of cells that we can find in the nasal cavity

A

ciliated cells
goblet cells

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6
Q

the main regions of the nasal cavity

A

olfactory region
respiratory region
vestibular region

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7
Q

order the regions of the nasal cavity based on surface area

A

respiratory region has the highest surface area, then the olfactory region, then the vestibular region

note that the respiratory region is highly vascularised

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8
Q

there is direct access to the brain via the olfactory region, true or false

A

true
Olfactory region is the only part in the whole body where CNS is in contact with the peripheral environment

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9
Q

the significance of a large surface area in nasal drug delivery

A

rapid drug absorption and systemic delivery

improved CNS drug delivery

local drug delivery for respiratory conditions

(the avoidance of first pass metabolism in nasal drug delivery is key)

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10
Q

describe mucocilliary clearance

A

Mucociliary clearance, also known as the mucociliary escalator, is a vital defense mechanism of the respiratory system that removes inhaled particles and pathogens by trapping them in a layer of mucus and then propelling them towards the oropharynx for removal

could also say Mucociliary clearance is a primary innate defense in the upper and lower airways. Pathogens, including viruses, are trapped in the mucus layer and then removed from the airways by motile cilia. Viruses can target this mucociliary defense through various mechanisms.

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11
Q

when is mucocilliary clearance compromised

A

if there are abnormalities with the cilia, mucus or periciliary fluid

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12
Q

what happens when there is too much secretion of periciliary fluid

what happens when there is too little secretion of periciliary fluid

A

Too much secretion of periciliary fluid → complete cover of the cilia

Too low secretion of periciliary fluid → cilia tangled in the mucus gel

The periciliary fluid, also known as the sol layer, is a thin, watery layer of fluid that lies beneath the mucus layer in the respiratory tract, including the nasal cavity and lower airways. It plays a crucial role in mucociliary clearance, ensuring efficient removal of inhaled particles, pathogens, and excess mucus.

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13
Q

the role of the cilia in the nasal cavity

A

Hairlike structures called cilia line the mucous membrane and move the particles trapped in the mucus out of the nose. so basically the cilia helps filter the air in that enters the nose

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14
Q

the periciliary fluid is primarily found in the respiratory region of the nasal cavity, true or false

A

true

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15
Q

Cystic fibrosis, asthma, chronic bronchitis, COPD or acute RDS might cause an increase in the viscoelasticity of the nasal mucus, true or false?
if this happens, how would that affect MCC (mucociliary
clearance.)

A

true
it will slow down mucocilliary clearance

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16
Q

name some protective substances secreted by the nose against pathogens and what they do

A

IgA , to prevent attachment of bacteria to the mucosa

Lysozymes, to protect the cells against infections by attacking cell walls of microorganisms.

17
Q

the average pH of nasal secretions in adults and in children

A

5.5-6.5

5.0-6.7

18
Q

nasal secretions become more acidic in conditions like acute rhinitis, and acute sinusitis, true or false

A

false
they become more alkaline

19
Q

some examples of nasal secretions

A

water
immunoglobulins
electrolytes
proteins
salts
WBCs…etc

20
Q

which nasal secretion(protein) acts as an antibacterial and what happens to it’s activity in alkaline pH

A

lysozymes

it’s activity is dimished

21
Q

the olfactory mucosa is in direct contact with the brain and CSF, true or false

A

true

i.e medications absorbed across the olfactory mucosa directly enter the brain

22
Q

describe the nose-brain pathway

A

The “nose-to-brain pathway” refers to the direct route from the nasal cavity to the brain, bypassing the blood-brain barrier (BBB), primarily through the olfactory and trigeminal nerve pathways, which is being explored for drug delivery and other therapeutic applications.

23
Q

name some advantages of nasal drug delivery

A

Large SA (~160 cm2) available for drug absorption.

High blood vascularity (rich blood supply) → rapid absorption to the systemic circulation + rapid onset of action.

Non-invasive delivery route.

Ease of administration.

Enzymatic activity in the nasal cavity < the GIT → delivery via the nose appropriate for many drugs especially peptides.

A good alternative to GIT for patients who have N&V or swallowing difficulties, for drugs that undergo extensive first pass effect or have detrimental effects on the GIT
epithelium.

24
Q

What are the two primary routes of drug absorption after nasal administration?

A

Systemic circulation (blood) via the nasal epithelium.

Direct transport to the brain via the olfactory region and cerebrospinal fluid (CSF).

25
How does nasal drug delivery bypass the first-pass effect?
Drugs administered nasally avoid gastrointestinal (GI) metabolism and hepatic first-pass degradation, allowing for higher bioavailability.
26
What role does the olfactory region play in nasal drug absorption?
The olfactory region provides a direct pathway to the brain via the cerebrospinal fluid (CSF), enabling rapid drug delivery to the central nervous system (CNS).
27
What are the major factors limiting drug absorption through the nasal cavity?
Mucociliary clearance (MCC), enzymatic degradation, and barriers like the blood-brain barrier (BBB) for CNS-targeted drugs
28
some disadvantages of nasal drug delivery
mucocilliary clearance **Mucus** might act as a physical barrier to drug absorption. Mucins might bind to certain drugs and interfere with their absorption fragility of the nasal epithelium and cilia, making them liable to damage by certain drugs irreproducibility of absorption ## Footnote Irreproducibility = unpredictable drug absorption due to nasal condition variability (congestion, mucus, inflammation, sneezing). note that different nasal conditions may affect absoprtion differently
29
can vaccines be inhaled?
yes they could(**as per the slides and some research from google** )
30
some nasal drugs used for Management/treatment of symptoms of seasonal and perennial rhino sinusitis
Azelastine Beclometasone Budesonide Levocabastine Mometasone Sodium cromoglicate Triamcinolone acetonide
31
drug that can be delivered through the nasal route for; hormone replacement therapy smoke cessation B12 deficiency control of dehydration in diabetes insipidus treatment of post-menopausal osteoporosis treatment of prostate cancer treatment of migranes and cluster headaches pain management flu prevention ## Footnote this doesnt mean it is the only route they are delivered by but that they can be done this way
estradiol nicotine cyanocobalamin desmopressin Salmon calcitonin buserelin Zolmitriptan, sumatriptan fentanyl, butorphanol live attenuated influenza vaccines
32
what is the difference between a nasal spray and metered nasal spray
The primary difference between a nasal spray and a metered nasal spray lies in the dispensing mechanism. A nasal spray, typically a pump or pressurized canister, delivers a variable amount of medication, while a metered nasal spray delivers a precise, standardized dose with each actuation,
33
nasal drops vs nasal sprays
nasal drops are the most convenient system for nasal delivery, however they lack dose precision **nasal drops deposit drugs in the ciliated regions of the nasal cavity ** while nasal sprays can be more precise with the doses, and are available as both solutions and suspensions **they deposit drugs towards the frontal regiond og the nose (non ciliated regions)** ## Footnote Nasal sprays deliver medication directly to the lining of the nasal passages, targeting specific areas.** Nasal drops,** on the other hand, are often formulated to distribute more evenly throughout the nasal cavity, potentially reaching the back
34
name some dosage forms for nasal delivery
nasal sprays nasal drops powder gel Mucosal atomisation device(MAD)
35
anything you know about Mucosal atomisation devices
Atomisation results in higher bioavailability than either nasal spray or drops. designed to allow emergency personnel to deliver nasal medications ## Footnote A Mucosal Atomization Device (MAD) is a medical device used to deliver medication to the mucosal surfaces of the body, typically via the nose or mouth, **by turning liquid medication into a fine mist**. This method allows for rapid absorption of the medication into the bloodstream.
36