Lecture 17 - Absorption of molecules 2

Question 1

bioavailability

Answer 1

how much of drug enters systemic circulation and is accessible at site of action.

Question 2

Adsorption

Answer 2

sticking to surface of something

Question 3

Micellar solubilisation

Answer 3

done by bile salts, to make lipophilic molecules more soluble. Stage 1 and 2, surfactants start to be added, 3 total surface of water covered by surfactants, this is the Critical Micelle Concentration (CMC), where no space on surface left for surfactants to go. 4- micelles form, hydrophobic cavity made by hydrophobic tails all pointing inwards. Lipophilic drugs become ‘trapped’ within micelles, solubilising lipophilic drugs in water or other polar solutions.

Question 4

CMC

Answer 4

Critical micelle concentration

Question 5

Large pka

Answer 5

weak acids (dissociate less)

Question 6

pKa

Answer 6

-when 50/50 of molecules are ionised/molecules.

Question 7

Surfactant molecules

Answer 7

have hydrophobic tail and hydrophilic heads. E.g stearic acid

Question 8

R-OH pKa range

Answer 8

16-19