Exam 3 Spring 2017 Flashcards
What are the sizes of particles that get stuck in to nasopharyngeal region?
10-30 microm
What are the sizes of particles that get stuck in to bronchiolar region?
5-10 microm
What are the sizes of particles that get stuck in to alveolar region?
1-5 microm
What are local advantages of nasal drug delivery?
- Ease of administration
- Rapid absorption and onset of action
- Reduction in systemic side effects
What are systemic advantages of nasal drug delivery?
- Rich vasculature underlining the nasal mucosa
- does not undergo first pass metabolism
- Rate and extent of absorption similar to IV (for some drugs)
Disadvantages of nasal delivery
- Small site for absorption
- Mucociliary clearance
- Potentially short residence time
- Efficiency of delivery is important
What does formulation enhancers do to the drug?
- increase absorption
- increase time spent in cavity via mucoadhesives
What happens with chronic use of formulation enhancers for nasal routes?
nasal irritation
What are the types of dosage forms for nasal delivery?
- solution: drops, spray pump
- suspension sprays
- gels
- emulsions and ointments
- DPI
Factors that affect drug absorption
- size of drug molecule
- partition coefficient (lipid solubility)
- drug concentration
- ionization state of drug
- pH of absorption site
- vehicle for drug delivery
- mucosal contact time
What are the types of solubilizers or co-solvents for nasal dosage form?
– Alcohol, 200 proof (2%)
– Propylene glycol (20%)
What are surfactants used for in nasal dosage form?
to reduce surface tension for drug to penetrate membrane
What are tonicity agents used for in nasal dosage form?
so that tonicity in the nasal membrane is isotonic so it doesn’t get damaged
What is a popular bioadhesive?
chitosan
What are types of local action which nasal formulations can target?
- rhinitis
- nasal pruritus
- sinusitis
- runny nose (rhinorrhea)
- prevent polyps
What are types of systemic advantages which nasal formulations can achieve?
- convenient
- more efficient dose/effect (propanolol)
- avoid first pass metabolism
What are the effects of nasal route to the brain?
- bypasses BBB
- delivered via neural pathways
- minimize systemic exposure
Describe the size requirements for delivery to brain from nasal route.
make sure the droplet sizes are on the lower side (10 micron) so that it’s more sensitive to the upper concha to go to the brain
Define aerosol
dispersion of particles or droplets suspended in a gas or vapor
What are advantages of local delivery with respect to pulmonary route?
- can treat asthma, COPD
- rapid onset
- no interactions with food
- more acceptable then injections
What are advantages of systemic delivery with respect to pulmonary route?
- avoids first pass metabolism
- large surface area: (120 – 160 m2, ~ tennis court)
What are limitations of pulmonary route?
- lungs designed to prevent inhalation of exogenous compounds / particulates
- oropharyngeal irritation, taste
Define aerodynamic diameter
“How well the droplet or particle can fly in a stream of air”
What are the types of aerosol deposition?
- for >5 microm: electrostatic attraction, interception, impaction
- for <5 microm: gravitational settling (sedimentation), brownian diffusion