Stability parameters on pharmaceuticals, foods, and cosmetics were covered in earlier articles. These constitute a major segment for predicting the shelf life of products but such studies extend to other materials as well such as building materials, electronic components, packaging materials, etc. Testing for such materials requires extremes of environmental conditions such as temperatures ranging from liquid nitrogen temperature (-185°C) to above 200°C and relative humidity’s ranging from 20 – 98% for extended periods of time. It is not practical for you to move to different climatic regions every time for the purpose of study with your samples. Stability chambers offer the required conditions to conduct such studies in your laboratory wherever you may be located.
Stability testing chambers are designed specially to conducts stability and shelf life studies on different products. Broadly speaking depending on application they are classified as
- Environmental chambers
- Temperature – humidity chambers
- Accelerated test chambers
- Photostability chambers
The chambers conform to international standard guidelines and have internal mirror finish corrosion resistant stainless steel body with insulated exterior MS sheet having white powder coating. The door has a magnetic gasket with key coded door lock. High quality stainless steel trays are provided for storage of samples. Cooling is affected by hermetically sealed compressor. Controlled airflow inside ensures even distribution of humidity and temperature.
Reach- in chambers are small in size and are convenient to use when the number of samples is less and conditions are likely to be changed
Walk-in chambers are larger in size and suitable when large number of samples are to be stored and when storage conditions are to be maintained over extended time periods
Separate chamber is to be maintained for each required condition of storage. As per International Commission on Harmonisation (ICH) the prescribed temperature and humidity conditions for stability studies on pharmaceuticals are
Long-term studies: 25°C +/- 2°C, 60 +/- 5%RH
Intermediate studies: 30°C +/ – 2°C, 65% +/- 5% RH
Accelerated stability studies: 40°C +/- 2°C, 75% +/- 5% RH
Stability data is valid only if the environmental conditions are consistent during product exposure. For this condition to be met it is imperative that automated data logging is carried out at regular time intervals and preventive maintenance routines are carried out regularly on stability chambers to ensure trouble-free operation over extended periods of exposure.
Please feel free to offer your suggestions and comments.