First-Order Kinetics

Question 1

First-order kinetics

Answer 1

-time vs concentration

Question 2

Rate of degradation (1st order)

Answer 2

= -kCa
-proportional to concentration

Question 3

Rate of degradation

Answer 3

ln(Ca/Cao) = -kt

Question 4

Linear kinetics

Answer 4

-concentration vs time
-exp (-kt) slope
-INCREASE concentration DECREASES k

Question 5

natural log kinetics

Answer 5

-log vs time
-slope= -k
-k decreases with increasing log

Question 6

Half-life

Answer 6

-time for drug to decrease to half its value

-one half-life when Ca/Cao = 0.5

Question 7

first order half-life

Answer 7

t= 0.693/k

Question 8

shelf-life

Answer 8

-time where drug maintains properties within specified limits
-aim for 2 years
-usually t90% = ln(0.9)

Question 9

Expiration date

Answer 9

end of shelf life

Question 10

shelf life equation

Answer 10

t90 = ln (0.9)
ln(0.9) = -kt

Question 11

1st order kinetic Rate of drug degradation is proportional to

Answer 11

-concentration

Question 12

Drug concentration decreases

Answer 12

EXPONENTIALLY with time

Question 13

Zero-order kinetics

Answer 13

-rate of drug degradation CONSTANT
-drug in solution or solid

Question 14

Rate of drug degradation (0 order)

Answer 14

-CONSTANT
-independent of concentration
= -k

Question 15

Degradation equation (0 order)

Answer 15

Ca = Cao -kt

Question 16

0 order kinetics

Answer 16

-half life depends on initital concnetration
-can estimate temp and pH

Question 17

negative concentrations

Answer 17

t> (Cao/k)
-predicted by 0 order

Question 18

2nd order

Answer 18

-need for binary reactions
-A+B=C
= -k (Ca)^2

Question 19

2nd order equation

Answer 19

1/Ca = (1/Cao) +kt