CHEM KINETICS PART 1 Flashcards
To ensure that the patient receives the correct dose of a drug, the ____ must be known
rate of degradation
are chemical in nature and take place at definite rates
degradative reactions
the study of rate of a chemical reaction
chemical kinetics
speed of a chemical reaction
reaction rate
RAEACTION RATE
relationship between time, drug, and degradation
as time increases, drug decreases, degradation increases
drug degrades over time
- Deals with the stability of drugs and the mode of action of their degradation through the examination of rate of reaction.
- Can provide predictive information to anticipate stability problems
chemical kinetics
CHEMICAL KINETICS
Deals with the stability of drugs and the mode of action of their degradation through the examination of ____
RATE OF REACTION
CHEMICAL KINETICS
Can provide ____ to anticipate stability problems
PREDICTIVE INFORMATION
TYPES OF ORDER OF REACTION
constant amount is degraded
e.g. alcohol, aspirin
zero order
TYPES OF ORDER OF REACTION
follows zero order kinetics
straight line
the time required for one-half (50%) of the material to disappear
HALF-LIFE
the time required for 10% of the material to disappear
SHELF-LIFE
TYPES OF ORDER OF REACTION
constant fraction/percent of drug is degraded over time
first order kinetics
first order kinetics follows a what type of line
curved line
determination of order of reaction
graphical
half-life
REACTION RATE
ZERO order
independent to C
REACTION RATE
FIRST order
directly proportional to C
HALF LIFE
ZERO order
directly proportional to C
HALF LIFE
FIRST order
independent to C
the time period during which a drug product is expected to remain within the approved specification for use, provided that it is stored under the conditions defined on the container label
shelf life
the date placed on the container label of a drug product designating the time prior to which a batch of the product is expected to remain within the approved shelf-life specification
expiration date
DETERMINATION OF SHELF LIFE
used to predict temperature stability
arrhenius equation
DETERMINATION OF SHELF LIFE
can estimate the effect of a 10° rise in temperature on the stability of pharmaceuticals
Q10 method
EVALUATION OF STABILITY OF DRUG PRODUCTS
designed to increase the rate of chemical degradation or physical change of a drug or drug product by using exaggerated storage conditions
accelerated stability studies
EVALUATION OF STABILITY OF DRUG PRODUCTS
- carried out under more severe conditions than those used for accelerated testing
- High temperature, humidity, high or low pH
stress testing
DECOMPOSITION & STABILIZATION
- a chemical bond is split via the addition of water
- e.g. esters and amides
- Protection:
1. pH buffers
2. Type of solvent
3. Structure modification
hydrolysis
DECOMPOSITION & STABILIZATION
- transfer of electrons
- e.g. steroids, vitamins, antibiotics
- Protection:
1. Low O2 content
2. Antioxidants
3. pH buffers
4. Type of Solvent
oxidation
DECOMPOSITION & STABILIZATION
- absorption of radiant energy in the form of light
- e.g. nifedipine, hydrocortisone
- Protection:
1. Storage condition
photolysis
FACTORS THAT AFFECT REACTION RATES
- a substance that increases the reaction rate WITHOUT undergoing a net chemical change itself
- lowers Ea
catalyst
FACTORS THAT AFFECT REACTION RATES
- increase in KE
- faster molecules
- more collision
- the reaction rate of virtually all reactions increases with increasing ____
temperature effects
FACTORS THAT AFFECT REACTION RATES
- more reactant particles that collide
- more often a reaction can occur
- the reaction rate usually increases as the ____ of the reactants increases
concentration effects
reactions occur when reactant molecules EFFECTIVELY COLLIDE
COLLISION THEORY
facilitate the breaking and forming of bonds and the rearrangement of atoms
effective collision
