Variant 7-iontophoretic permeabilty of skin in vio

Question 1

AIM

Answer 1

to determine the coefficient of iontophoretic permeabilty for novacin ions of human skon in vivo

Question 2

Represent schematically the experimental setup for iontophoretic drug delivery into the skin
and explain the operation procedure.

Answer 2

Look at drawing i bok

• Chamber placed on skin, second electrode placed few cm away
• Novacaine ions pumed in (+ charge). Cl- moves the opposite direction
• The mass of the drug transferred into the skin can be determined by comparing it to the mass of the Cl-.
• Use method of mohr for titration

Question 3

Write the definition equation from the coefficient of iontophoretic permeability of the skin
(k) the physical meaning of the parameters involved. (9 points)

Answer 3

K=m drug/ QxS ( Kgx C-1 x m-2)

Q= electricity
S=area
m=mass of drug

Question 4

List the three basic applications of iontophoretic in dentistry? (3 points)

Answer 4

• Treta hypertensive dentin using negative fluoride ions
• Treatment of ulcers and herpes using corticosteroids
• Application of anesthetics

Question 5

Give the Nernst equation for the equilibrium potential and show the graph for the
dependence on time.

Answer 5

Pn= -RT/zF ln c2/c1

Then draw that half trapezium graph

Question 6

Write the formula for the partition coefficient (k) for a substance with hydrophobic character.
(6 points)

Answer 6

P= K Dm/l

k= partition coefficent
D= coefficient of diffusion
l= memebrane thickeness

Question 7

The dependence of the concentration changes (IgC/C) of the Cl- with the time of dialysis in
the artificial kidney (t).(5 points)

Answer 7

descendig slope

find log0.5 which is -0.3 then follow up time