class 3

Question 1

limits to the absorption of drugs after oral administration

Answer 1

limits due to first pass effect-some of the drug Is metabolized in the liver or gut

Question 2

Passive absorption rules of thumb (apical to basolateral)

Answer 2

MW <1

Question 3

sometimes junctions can open and close and allow some drugs through

Answer 3

paracellular

Question 4

drugs will perfuse or diffuse through cells

Answer 4

transcellular

Question 5

Transcellular (apical to basolateral route)

Answer 5

want drugs that are not very hydrophilic but lipophilic

Question 6

Lipinski Rule of 5: for Transcellular transport

Answer 6

should not have more than 5 hydrogen bond donors (ex: -OH, -NH)
should not have more than 10-H bond acceptors (O,N)
mw<500
Partition coeffient less than 5

Question 7

facilitated by transporters (proteins that can take specific molecules and carry them into enterocytes to basolateral side)

Answer 7

Transcellular with transporters (apical to basolateral)

Question 8

increase drug concentration on lumen side but wont necessarily increase absorption

Answer 8

transcellular with transporters

Question 9

transcellular with transporters

Answer 9

does require energy

Question 10

Drugs on both sides

can have two types of transporters

Answer 10

active transport

Question 11

Eflux transporters

Answer 11

taking drugs that already been absorbed and kicking it back out of the cell

Question 12

most of blood flow coming from intestinal cells will feedback into portal vein into the liver

Answer 12

important aspect to consider for oral administration of drugs

Question 13

Models for assessing intestinal absorption

Answer 13

PAMPA
Cell culture models
caco-2, mdck, mdck-mdr, 2/4/A1,HT-29, intestinal tissue

Question 14

Most common-grow cell culture membrane monolayer-takes 21 days, disadvantage-does not contain efflux transporters like P450, put drug in top chamber and see how long it takes to cross cultured membrane to bottom chamber

Answer 14

Caco-2/ Transwell System