Home
Flashcards
Preview
Dosage forms exam 1 stability 3
Home
Get App
Take Quiz
Create
Chemical kinetics equations
Rate= +/- dC/dT Concentration over time
rate=k (a+b)[A][B]
Reaction rates depend on
Temperature
Order of the reaction
Sum of the exponents
What are the greatest interest of reactions?
Zero, first and second (mainly zero and first)
In First order Rate is proportional to
Concentration
For first order reaction, plot of integrated Ln C vs T... (lnC=lnCo-K1t)the slope is what?
-K1
Example of pseudo first order degradation
Ester Hydrolysis
Pseudo first order equation
-dCE/dt= kCE
Zero Order equation
-dC/dt=kC^0
Zero order graph equation
C=Co-kot
Co is intercept
slope is ko
To maintain constant concentration for zero order
There is a resevoir of drug to replac the drug that is lost to decomposition
Effects of pH on degradation rate
Protons and hydroxyl ions can catalyze reactions (Ester hydrolysis)
Max stability is located where at the graph?
Where log k is at its lowest.
Temperature affect on degradation rates.... 10 Celcius increase causes
2-5 fold decay rate increase
Arrhenius equation
k=Ae^-Ea/RT
Arrhenius used to predict
Shelf life for normal conditions
Ampicillin freezing causes
Pockets of increased conc. causeing increased degradation rate
buffers in solution when freezing
Can alter pH during freezing process.
Author
swynocker
ID
45366
Card Set
Dosage forms exam 1 stability 3
Description
Stability 3
Updated
2010-10-27T05:42:42Z
Show Answers
Home
Flashcards
Preview