Accelerated stability studies assess product shelf life by simulating decomposition through elevated temperatures, humidity, and light. Utilizing the Arrhenius equation, key steps include storing drug preparations at various temperatures, calculating reaction rates, and extrapolating data to predict shelf life at room temperature. Limitations include applicability only to temperature-dependent reactions and in situations where the product maintains integrity under stress.

1. Presented by:
Mahewash Sana A. Pathan
ACCELERATED STABILITY
STUDIES

2. ACCELERATED STABILITY STUDIES
 Stability study to predict the shelf life of
product, by accelerating the rate of
decomposition, preferably by increasing
temperature of reaction.
 These are experimental designs.
 Preparations are subjected to high stresses
during stability testing such as-
1. Temperature
2. Humidity
3. Light

3. ARRHENIUS EQUATION
 It explains the effect of temperature on the rate of reaction.
 According to Arrhenius, with every 10°C rise in temperature, the
rate of reaction increases by 2-3 times.
 Arrhenius factor represents frequency of collisions between two
molecules.
 Activation energy (Ea) is the amount of energy that is required for a
reaction to get started.

4. STEPS INVOLVED IN PREDICTION OF SHELF
LIFE
1. Drug liquid preparations are stored at elevated temperature, i.e.
50, 60, 70, 85, 100 & 121°C. In addition, samples studied at
40°C/75% RH & 35°C.
2. During different time intervals, samples are withdrawn (0, 3, 6
months).
3. The order of reaction is determined by plotting the concentration
against time & ‘k’ value is calculated from the slope.
4. Similar graphs are drawn at different elevated temperature, ‘k’ value
for each temperature is calculated.

5. 5. By using Arrhenius equation, log k values are plotted against
reciprocal of temperature.
6. The plot is extrapolated to room temperature, 25°C to
determine k value. This k value is substituted into shelf life
equation to determine shelf life of product.

6. Climatic zones
 Due to the diverse climatic conditions prevalent in
different countries, four climatic zones are proposed in
ICH guidelines.
CLIMATI
C ZONE
DESCRIPTION STORAGE
CONDITIONS
COUNTRIES
I Temperate
zone
21°C/45% RH Great britain,
northern Europe,
Canada, Russia
II Subtropical &
Mediteranean
25°C/ 60% RH USA, Japan,
Southern Europe
III Hot & dry 30°C/ 35% RH Iran, Iraq, Sudan
IV Hot & humid 30°C/ 70% RH Brazil, Ghana,
Indonesia, India,
Philippines.

7. LIMITATIONS OF ACCELERATED
STABILITY STUDIES
 This studies are only valid when the breakdown
depends on temperature.
 this method is not used in case of complex reactions.
 This method is valid only if energy of activation lies
between 10-30Kcal/mole.
 The products which loose their physical integrity at
elevated temperature is not suitable for accelerated
testing.
 This method is not valid when order changes at
higher temperature.