Partitioning (w25)

Question 1

What is partitioning ?

Answer 1

Partitioning is the distribution (or moving) of a substance between two immiscible phases

Question 2

What is partition coefficient (P) a measure of ?

Answer 2

P is a measure of relative affinity of the solute for an aqueous and a lipid phase at equilibrium – it will be constant

Question 3

What does partition coefficient (P) only apply to ?

Answer 3

Only applies to dilute solutions, i.e. ideal solutions

Question 4

What does log P do ?

Answer 4

Gives an indication of the lipophilicity of a drug

Question 5

When will there be two species present during partitioning ?

Answer 5

If the pH is changed and ionisation occurs in the aqueous phase, then there will be two species present

Question 6

What is the organic phase equivalent to ?

Answer 6

The lipophilic regions in the body

Question 7

What is the aqueous phase equivalent to ?

Answer 7

The aqueous regions in the body

Question 8

What is MAC ?

Answer 8

MAC = minimum alveolar concentration (the lower this is the more potent the anaesthetic is)