EXAM 2 L1

Question 1

Bioavailability definition

Answer 1

Refers to the rate and extent of drug absorption

Question 2

Absolute Bioavailability

Answer 2

the AUC of a given dosage form compared with the AUC of the same dose injected intravenously

Question 3

Relative Bioavailability

Answer 3

Refers to the AUC of a given dosage form compared to an arbitrary reference standard

Question 4

Bioequivalent does not mean…

Answer 4

The therapeutic effect of two dosage forms are equivalent

Question 5

Most important factor in pharma and toxicology

Answer 5

Dose-response relationship

Question 6

Dose covers two aspects:

Answer 6

The amount of chemical in which the whole organism is treated
The local concentration of the chemical at the biological response site

Question 7

T/F: relationship between dose and receptor concentration is a function of the ADME

Answer 7

True

Question 8

Three levels of dose response

Answer 8

Toxic Response
Safe and Efficacious
Not Efficacious

Question 9

Processes required for oral absorption if Monolithic dosage forms

Answer 9

dissolve to saturated solution
dissolved - diffuse from the area of high to low conc.
Molecules diffuse through the bulk solution
Replenishment of drug molecules in the diffusion layer is achieved by further dissolution

Question 10

T/F: Surface area increases when solids are broken up into smaller pieces

Answer 10

True

Question 11

Rate of Dissolution equation

Answer 11

(dM/dt)

Question 12

Rate of dissolution definition

Answer 12

The change in the amount of mass that appears in solution over time

Question 13

Rate of dissolution dependent on…

Answer 13

D-Diffusion Coefficient (Fick’s 1st)
S- surface area of tablet/granules available to donate drug to solution
h-thickness of stationary layer
Cd-concentration of drug in the donor (X=0)
Ca-Concentration of drug in bulk solution (x=h)

Question 14

Noyes-Whitney equation

Answer 14

(dM)/(dt )= (DS)/(h)(Cd-Ca)

Question 15

Dissolution rate is proportional to…

Answer 15

D (diffusion)
Tablet/particle surface area
Difference in the concentration gradient

Question 16

T/F: Dissolution rate is inversely proportional to h

Answer 16

True

Question 17

Permeability vs dissolution

Answer 17

Permeability - diffusion across a barrier (cell membrane) instead of across an unstirred layer

Question 18

Permeability needs to include

Answer 18

Partition coefficient K to account for changes in environment between inside and outside barrier (water vs hydrophobic core of membrane)

Question 19

Permeability abbrev.

Answer 19

D = Diffusivity
S = Surface area of the boundary (GI surface area)
K = Partition Coefficient
Cd = Donor (GI) concentration
h= thickness of barrier (thickness of GI cell membrane)
P = (DK)/h=permeability

Question 20

3 factors can limit the ability of a drug to absorb after oral administration

Answer 20

Solubility
Dissolution
Permeability

Question 21

Limited Solubility effects

Answer 21

represented as a small Cd value in previous equations
Dosage form dissolves fast and drug permeates readily
Increasing dose doesn’t increase blood levels as the GI fluids are already saturated

Question 22

Limited Dissolution effects

Answer 22

Drug is unable to dissolve into the solution from the dosage form in sub-saturated fluid
Dissolution time is greater than the time for absorption in the intestines
Often due to poor formulation/manufacturing
Need to have a tablet that can dissolve but also stand up to shipping and handling

Question 23

Limited permeability effects

Answer 23

Characteristic of the API itself similar to solubility limited
Dissolution is fast with sub-saturated fluids
Increasing the amount of drug increases absorption
See notes up to now and previous slide with permeability equation

Question 24

Definition of generic drug

Answer 24

A drug product that is comparable to a brand/reference listed drug product in dosage form, strength, route of administration, quality and performance characteristics, and intended use

Question 25

Therapeutic equivalence two factors

Answer 25

Pharmaceutical equivalence
bioequivalence

Question 26

Cmax definition

Answer 26

The max blood/plasma concentration from a dosage form

Question 27

Tmax definition

Answer 27

Time to reach the max blood/plasma concentration from a dosage form

Question 28

AUC

Answer 28

Area under the curve