Lecture 4B: Toxicokinetic P2

Question 1

Degree of Ionization is denoted by the pka

Answer 1

also known as the ionization constant or dissociation constant. It measures the weakness and strength of an acid or base.

Question 2

The higher number the _____ the acid

Answer 2

weaker

Question 3

The pKa of a compound is said to be

Answer 3

the pH at which the state is 50% ionized and 50% unionized.

Question 4

The degree of ionization of a chemical depends on

Answer 4

the pka of the compound and the pH of environment

Question 5

For acids as alkalinity gets greater it

Answer 5

moves from nonionized form to ionized form

Question 6

For bases as acidity gets greater it

Answer 6

move from ionized form to nonionized form

Question 7

For Bases as alkalinity greater it

Answer 7

moves from ionized form to nonionized form

Question 8

For bases As acidity gets greater it

Answer 8

moves from nonionized form to ionized form

Question 9

Henderson–Hasselbalch equation for acid

Answer 9

pH = pKa + log10 ([A–]/[HA])

Question 10

Rules for pKa

Answer 10

1. If pKa - pH = 0, then 50% of drug is ionized and 50% is unionized
2. An acid in an acid solution will not ionize
3. An acid in a basic solution will ionize
4. A base in a basic solution will not ionize
5. A base in an acid solution will ionize
6. Positive P or Log P states high lipophilicity
7. Negative P or Log P states low lipophilicity

Question 11

Henderson–Hasselbalch equation for bases

Answer 11

pKa = pH - log[B]/[BH+]

Question 12

Henderson–Hasselbalch equation for acidic drug

Answer 12

pKa = pH - log[ionized]/[unionized]

Question 13

Henderson–Hasselbalch equation for basic drug:

Answer 13

pKa = pH - log[unionized]/[ionized]

Question 14

What is the pH of Stomach & Gastric Juices?

Answer 14

3

Question 15

What is the pH of Plasma?

Answer 15

7.4

Question 16

What is the pH of Urine?

Answer 16

8

Question 17

What is the pH Partition?

Answer 17

it refers to the accumulation of the acid or base in respect to the pH of the environment over compartments with varied pH.