C. Pharmaceutics

Question 1

for doses to be effective

Answer 1

Deposit in appropriate region
right quantity
cross barriers and defence mechanisms

Question 2

inertial impaction mechanism

Answer 2

bigger particles deposit quickly in the upper airways due to higher inertia
scales with mass

Question 3

sedimentation mechanism

Answer 3

gravity can pull particles to airway surface

scales with mass

Question 4

aerodynamic diameter

Answer 4

a particle can be more than 10 microns but behave as 3 microns, due to less daer

Question 5

interception mechanism

Answer 5

particles contact airway surface due to the size/shape

Question 6

Respirable fraction

Answer 6

percentage of particle that are less than 5 um, hence likely to be deposited.

Question 7

sizing of particles in inhaled products

Answer 7

Microscopy (labour intensive)
laser diffraction
aerosizer

Question 8

Microscopy

Answer 8

electron or optical
need to be aware of irregular 3d particles when observing
good observation for shape
difference between projected area diameter and projected perimeter diameter

Question 9

laser diffraction

Answer 9

measures light diffraction pattern - size

assumes spherical particle

Question 10

aerosizer

Answer 10

measures time particle needs to move through laser
small particle - faster
0.2-700 microns

Question 11

impaction methods of measuring aerodynamic diameter

Answer 11

predict site of deposition in lung

using inertial impaction mechanism

Question 12

Twin liquid impinger in seperating large and small particles cut off-6.4 microns

Answer 12

two stages
cheap, simple
BP accepted but not USP

Question 13

Andersen cascade impactor

or Next generation impactor

Answer 13

8 stages
size distribution information
labour intensive
accepted by BP and USP

Question 14

Eye drug delivery lecture

Answer 14

anterior and posterior segments completely separated.

tear film three layers, lipid, aqueous, mucin.

Question 15

if disease is before cornea can be treated with eyedrops

Answer 15

behind cornea only 1-5% can be absorbed

Question 16

reason why low absorption in anterior segment

Answer 16

tear drainage (drug diluted)
absorption into system circulation 
protein binding in tear film
corneal barrier (drug has to have correct hydro-lipo philicity)

Question 17

Eye drops

Answer 17

solution- free of particles
suspension- particles less than 50 microns
ph 7.4
isotonic
sterile using preservatives max 10 ml

Question 18

eye ointments

Answer 18

dispersed in semi-solid greasy base
max 50 micron particles
no preservatives as no water

Question 19

Nasal drug delivery lecture

Answer 19

Regions: Vestibule, Atrium, Turbinates, olfactory, nasopharynx
Turbinates (warm, humidify, filter air) increase SA

Question 20

Respiratory epithelium

Answer 20

ciliated and non ciliated cells, goblet, basal cells
mucus
vascularised
large SA - rapid absorption

Question 21

advantages in nasal delivery

Answer 21

easy acces
non invasive
avoid GI tract
rapid absorption
easy formulation

Question 22

limitations of nasal delivery

Answer 22

small cavity
mucociliary clearance - 15-20 min
high cyp450 and proteases
systemic side effects

Question 23

Nasal sprays

Answer 23

particles > 50 microns
easier to administer
must be: aqueous, isotonic, physiological pH.

Question 24

INHALERS 3

Answer 24

nEBULISER - aqueous solution
Pressurised meted dose inhalers (pMDI) liquified gas
Dry powder inhalers

Question 25

Nebulisers

Answer 25

Jet: air forced through a narrow hole | ultrasonic (portable): piezoelectric crystals

Question 26

Nebuliseer advantage

Answer 26

``` aqueous (simple for soluble drugs) no hand lung coordination large doses inhalaiton manoeuvre not needed low cost ```

Question 27

Disadvantages nebuliser

Answer 27

not protable yet long time low efficiency (10% reaches lungs) micorbial contamination

Question 28

`pMDI

Answer 28

inhaler label container: strong(pressure), robust, light, inert. propellant: liquid under pressure - gas in atmospheric, vapour pressure needs to be constant, nonflammable, inert. Hydro fluoroalkanes (HFA)

Question 29

drug aspects

Answer 29

dose 5microns - 5 mg | particle size reduction needed - to deposit

Question 30

problems with suspensios

Answer 30

sedimentation flocculation (reversible) caking ostwald ripening

Question 31

pMDI advantage

Answer 31

``` portable multidose consistent formation and operation for all typees inexpensive dose uniformity ```

Question 32

pMDI Disadvantages

Answer 32

``` no breath actuation low lung deposition no dose counter on most low doses priming before use ```

Question 33

DPIs

Answer 33

drug more stable in dry form rather than in suspension | dose not constant - vary patient to patient

Question 34

main issues

Answer 34

<5 microns are cohesive, hard to separate | moisture increase agglomeration

Question 35

types os DPI

Answer 35

unit multiple unit reservoir

Question 36

types of DPI

Answer 36

unit multiple unit reservoir

Question 37

Disadvantages

Answer 37

Breath actuated(depend on patient effort) different designs humidity affected expensive