nasal drug delivery Flashcards
can you have systemic delivery when using nasal route
yes
can you have local delivery when using nasal route
yes
how are vaccines delivery through the nose
via delivery of antigen to nasal associated lymphoid tissue
what volume of liquid can the nose hold
12-15ml
surface area of the nose
150-180cm
what is the septum
a thin wall that provides support
(cartilage at front, bone at rear)
covered by a highly vascularised mucosa
what are the three turbinates
long, thin and curled bones that protrudes into the nasal cavity
covered by a highly vascularised mucosa
what do the turbinates and the septum do
- help perceive level of airflow through our nose
- clean and filter the air so that potential pollutant don’t enter the lungs
- humidify the air to help prevent dryness of the lungs
- warm the cold air to the body temp which helps lung function more effectively
where do most sinuses drain into
the middle turbinate
what do goblet cells secrete
mucus which coats the turbinates
what do epithelia cells express
cytochrome P450 enzymes and various endo and expopeptidases
what is under the basement membrane
the lamina propria - where the blood vessels are located
what size of particles are retained in the nose during breathing
particles under 10 micrometers
what size of particles pass through the nose
particles under 2 micrometers
when developing drugs can you effect the mucocillary clearance
no, it is an important defence mechanism
what is the clearance half life of a particles trapped in the mucus layer
15-25 minutes
altered by factors such as smoking, disease, medicines
characteristics of mucosal barrier
- thin epithelia
- large SA
- well vascularised
- avoids FPM
what are the different ways of systemic absorption
- passive diffusion
- paracellular
- carrier mediated
- P-glycoprotein
- active transport
- endocytic M-cells
how to use nasal spray (steps)
- remove cap
- prime nozzle (spray once before use)
- blow nose before use
- close one nostril
- switch to other one
what does pump design of nasal spray effect
plume geometry and disposition
what influences spray plume
- pump design
- formulation factors such as viscosity
what does a high viscosity mean (nasal spray)
larger droplet generation due to less efficient atomisation
what can higher spray velocities result in
higher inertial impaction of droplets
what is xylometazoline (otrivine)
a sympathomimetic agent with a-adrenergic activity
it constricts blood vessels and allows easier breathing
