Biopharmaceutical Classification System

Question 1

The BCS is a system used to differentiate the drugs on the basis of their?

Answer 1

1) Solubility

2) Permeability

Question 2

NCS provides guidance on predicting?

Answer 2

BCS provides guidance for predicting drug absorption rate /extent, aiming to simplify and speed drug development

Question 3

In diffusion what is referred to as sink conditions?

Answer 3

When the solution in the receptor is constantly removed and replaced with fresh solvent to keep the concentration at a low level,

Question 4

How is steady state condition achieved?

Answer 4

it can be virtually achieve by having a perfect ‘sink’ in the receptor(Cr) and a high concentration solution in the donor compartment (Cd), e.g Cd» Cr. condition

Question 5

The correlation between permeability and solubility in lipids is appropriately named?

Answer 5

Overton’s Rule

Question 6

BCS classifies drugs into four classes based on?

Answer 6

1) drug permeability
(through the GIT membrane)
2)solubility (in GI fluids)

Question 7

What are the two key bio-pharmaceutical parameters used to determine drug oral absorption?

Answer 7

• Solubility (Cs, affect dissolution /release rate)
• Permeability (the ability to diffuse through the GIT
membranes)

Question 8

BCS divides compounds into which four categories?

Answer 8

Class I ‐ High Permeability, High Solubility
Class II ‐ High Permeability, Low Solubility
Class III ‐ Low Permeability, High Solubility
Class IV ‐ Low Permeability, Low Solubility

Question 9

How do we determine Permeability?

Answer 9

Extent of absorption in humans: ( Absolute bioavailability studies)
Intestinal permeability methods, such as:  In vivo or in situ intestinal perfusion studies in animals.  In vitro permeation experiments across
‐ excised human/animal intestinal tissue ‐ epithelial cell monolayers