Lecture 3: Intro to Oral Drug Absorption

Question 1

what is the typical dosage form for oral administration?

Answer 1

solid (tablets/caps)

Question 2

what is the rate determining step in oral administration of of solid drugs?

Answer 2

disintegration/dissolution

Question 3

disintegration/dissolution can be affected by which 4 factors?

Answer 3

1. drug formulation (EC, IR etc)
2. surface area
3. pH
4. stirring

Question 4

a larger surface area causes ___ absorption

Answer 4

increased

Question 5

the small intestine is the primary site of absorption because (3)

Answer 5

1. high surface area
2. lower pH than stomach
3. can be absorbed directly into bloodstream

Question 6

intestines have __ that increase surface area, which ___ passive diffusion

Answer 6

microvilli, increases

Question 7

___ pH helps with solubilization and absorption of weak acids

Answer 7

high (basic)

Question 8

release of ___ helps solubilization and absorption of lipophilic drugs

Answer 8

bile

Question 9

the small intestine has specialized ____ transporters that help in drug absorption

Answer 9

nutrient

Question 10

there is a ___ blood flow at the small intestine. what is the influence on absorption?

Answer 10

high; increases

Question 11

t/f the large intestine contains microvilli

Answer 11

false

Question 12

what 4 characteristics of the large intestine that make it unsuitable for absorption?

Answer 12

1. no microvilli
2. tight junctions don’t allow much passive diffusion
3. more drug efflux transporters
4. viscous contents decrease absorption

Question 13

the large intestine can only allow passage of drug ____ cells (through/between)

Answer 13

through

Question 14

passage through cells is called __

Answer 14

transcellular diffusion

Question 15

passage between cells is called __

Answer 15

paracellular diffusion