Drug stability 2 Flashcards
what is the the rate
of reaction determined by?
- undecomposition of drug
- decomposition of drug
What are the Orders of reaction commonly encountered in drug stability studies
- Zero order
- First order
- Second order
- Pseudo first order
- Pseudo zero order
describe zero order kinetics in drug decomposition?
The decomposition proceeds at a constant rate
independent of the concentration of any of the
reactants
describe first order kinetics in drug decomposition?
Independent of the initial concentration of the reactants
describe second order kinetics of drug decomposition?
The rate is determined by the concentrations of two
reacting species
describe pseudoplastic first order and provide example?
This occurs when there is more than 1 reacting species, but the reaction appears to follow first order kinetics
e.g a large excess of one reactant
describe pseudo zero order and provide example?
This occurs when there is 1 reacting species, but the reaction appears to follow zero order kinetics
e.g an excess of the drug
Typically 10 degrees increase in temperature cause a 2 – 5 fold increase in decay
•Arrhenius -type relationship. TRUE OR FALSE?
TRUE
Why stability testing?
- Provide evidence on how the quality of a drug substance or drug product varies with time under the influence of a variety of environmental factors such as
- Temperature
- Humidity
- Light
- Establish are-test period for the drug substance
- Because physical, chemical or microbiological changes might impact theefficiency and security of the final produc
What do the ICH do?
Joint initiative involving both regulators and industry as
equal partners in the scientific and technical discussions of the testing procedures which are required to ensure and assess the safety, quality and efficacy of medicines.
what are the objectives of the ICH?
create harmonisation between USA, japan and EU
What are stability testing performed on?
Drug Substances (DS) –the unformulated drug substance that may subsequently be formulated with excipients to produce the dosage form.
Drug Products (DP) –the dosage form in the final immediate packaging intended for marketing.
what are the Variables that might affect the stability of
a given API & dosage form?
1) Formulation
2) Packaging
3) Site and method of manufacture
4) Batch size
5) Batch to batch variability - the importance of process validation & quality risk
management
6) Container / labelling
7) Changes to product
what are Development studies?
- characterise compatibility with common excipients
- characterise stability profile of API
- characterise stability profile of early formulations
what are Confirmatory studies?
long term & accelerated studies on the product as it is
to be registered