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33 Cards in this Set
- Front
- Back
What are the benefits to nasal drug delivery?
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1) Desire local effect
2) Non-invasive route to the systemic circulation 3) Possible route to access the brain |
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How are drugs absorbed from the nasal cavity to the blood?
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Via transepithelial absorption - Namely paracellular and transcelluar pathways
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Which routes of administration is intra-nasal route more successful than?
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Transmucosal - buccal, pulmonary, rectal and vaginal
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What are the four conditions for application of nasal drug delivery?
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1) Rhinitis (Runny Nose)
2) Congestion 3) Systemic Drug Delivery 4) Vaccination |
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What are example nasal drug delivery treatments for rhinitis?
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1) Antihistamines
2) Corticosteroids |
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What are example nasal drug delivery treatments for congestion?
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1) Decongestants (vasoconstrictors)
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What are example nasal drug delivery treatments for systemic drug delivery?
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1) Hormones
2) Crisis Treatment |
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What are example nasal drug delivery treatments for vaccination?
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1) FluMist (live, attenuated influenza vaccine)
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What are some benefits to intra-nasal delivery?
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1) Non-invasive
2) Lower risk of infection/disease transmission 3) Ease of self-administration/dose adjustment 4) Large SA 5) Fast onset 6) Rich vascular sucmucosa & lymphatic system 7) Avoids first pass 8) Possible direct CNS pathway |
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What are some disadvantages to intra-nasal delivery?
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1) Limited to potent drugs/small volumes
2) Active mucocillary clearance 3) Enz degradation by nasal P450 4) Low permeability for hydrophilic drugs (needs large doses) 5) Low pH 6) Inter-individual variability 7) Low CNS delivery efficiencies for proteins |
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What are the main factors affecting absorption of drugs from the nasal cavity?
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1) The area available for absorption
2) Contact time between the drug and absorption site 3) Metabolism in the nasal passages 4) Pathology of the absorbing tissue |
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What are the four types of nasal epithelium?
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1) Squamous epithelium
2) Respiratory (ciliated pseudostratified cuboidal/columnar)) 3) Transitional (non-ciliated cubodial/columnar) 4) Olfactory (cilated pseudostratified columnar) |
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What is the function of the ciliated psuedostratified cubodial/columnar respiratory epithelium?
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1) Air conditioning
2) Air purficiation 3) Sense pain, temperature and touch **Motile** |
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What is the function of ciliated pseudostratified columnar olfactory epithelum?
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It mediates the sense of smell
**Non-Motile** |
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What is the transgeminal nerve responsible for?
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Relaying pain, pressure and touch
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What is the first line of defense in respiratory epithelium?
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The squamous epithelium (vestibule)
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Where in the nasal passage are mobile cilia?
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Olfactory Epi (non-motile, slow clearance)
Respiratory Epi (motile, fast clearance) |
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How long does it take for clearance of the bulk of mucus to move from to the nose to the nasopharynx?
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10-20 minutes --> 40% of dose is cleared rapidly in 20 minutes
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What factors effect mucocilary clearance?
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1) Cilia
2) Pericillary Fluid 3) Mucus (amount/viscosity) |
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What is an example disease state indicative of compromised mucocilary clearance?
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Cystic Fibrosis
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What is the main difference between nasal and oral drug absorption?
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Nasal absorption lacks M cells/Peyer's patches
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How do drugs move from the nasal mucosa into the systemic circulation?
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Via the venous system, the drug is absorbed directly into the vein which carries it directly to the heart. This also bypasses the first pass metabolism.
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What typically damages the peripheral olfactory system?
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1) Toxins
2) Bacteria 3) Viruses 4) Drugs |
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How would a nasally applied drug access the CNS?
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Via the peripheral olfactory system or transgeminal nerve
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What are four factors affecting nasal drug delivery?
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1) Disease
2) Enzymatic Activity (pseudo-1st pass effect) 3) Immunological Clearance 4) Mucous barrier |
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What are examples of changes to the mucus barrier which effect nasal drug delivery?
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1) Vasoconstrictors prevent drug absorption
2) Bloody nose, congestion and mucous discharge prevent mucosal contact 3) Destruction of nasal mucosa from surgery or past cocaine use 4) Mucolytics tend to increase absorption of peptides |
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What are the three general nasal drug delivery side effects?
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1) Nasal Irritation/Nose Bleeds (Physical Trauma)
2) Bad Smells/Taste (Olfactory Sys Stimulation) 3) Pain/Burning Sensation (Trigeminal Sys Stimulation) |
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What are seven formulation factors of nasal drug delivery?
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1) Must be potent
2) Molecular weight, <1000 da 3) Lipohilicity (i.n. better option than p.o.) 4) pKa & pH 5) Osmolality (isotonic to slightly hypertonic) 6) Stability in processing and storage 7) Compatibility with sprayer components |
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Describe nasal sprays and the disadvantage of using them
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They deposit as an aerosol of particles, droplets or particles suspended in droplets. The main problem is that they tend to deposit near the front of the nasal cavity (non-motile area) with little dose reaching the turbinates
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What is the optimal particle or droplet size range for deposit in nasal passages? What happens to particles above or significantly below this range?
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Particles or droplets in the 5 to 10 micrometers size range tend to deposit in the nasal passages. Particles larger than 10 micrometers are filtered out by the nose hairs, while particles less than 2 micrometers in size are normally not filtered out and may enter the lungs.
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What is the main problem(s) with nasal drops?
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1) They provide less reproducible dosing compared to nasal sprays
2) Awkward administration |
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What is the main benefit(s) with nasal drops?
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1) Large drug dispersion throughout the length of the nasal cavity
2) Immediate drug absorption/Quick Onset 3) More drug is deposited on motile areas meaning it is cleared more quickly 4) The drug is deposited as a film of drug solution |
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What are strategies for enhancing nasal permeation?
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1) Increase the area available for absorption
2) Prolong the contact time between the drug and absorption site 3) Decrease metabolism in the nasal passages 4) Understand pathology of the absorbing tissue |