Drug stability - lecture 1 Flashcards
What is the definition of drug stability?
The capacity of a drug to remain within established specifications of identity for a specified time.
What are the two main areas of drug stability?
Shelf-life
Stability after administration
what are some factors of drug stability ?
heat
light
oxidation
packaging
drug composition
What are the problems with instability ?
loss of drug through chemical reaction
Unpalatability
loss of efficacy
poor bioavailability
what is shelf life?
Shelf-life is the time taken to reduce concentration of a drug to 90% of original value.
What must you be aware to know the decomposition of a drug?
Must be aware of the chemical groups which may cause stability problems. Which will then prevent or minimise chemical breakdown.
What is Hydrolysis ?
breaking a bond to add water
What factors affect hydrolysis ?
pH - acid/base catalysts
Temperature
Solvent
Structure
Signs of physical instability
Volatility
uptake or loss of solvent
polymorphism
Signs of chemical instability
Hydrolysis
oxidation
elimination
recemisation
isomerisation
