Temperature mapping is important for pharmaceutical stability study. It ensures that every part of the stability chamber will maintain a stable temperature during use.
A successful temperature mapping include knowing the where to place your sensors.
Industry guidance instructs us that when determining mapping locations, the potential storage location should be considered along with the following:
- worst place locations
- usable space
- direct path of air flow
- sensors being placed in a uniform pattern in all three dimensions of your space
- all sensors, other than the one in the center, should be placed away from the nearest wall at a distance that will define the actual volume of the space used for storage.
- not using the floor as a location for a fixed load as it needs to be available for cleaning
- adequate space should be provided for cleaning walk-in cold rooms, freezers and refrigerators
- storage locations for standalone CTC's should follow manufacturers recommendations to ensure adequate space inside for air movement
- the storage locations and extreme points of the stored load, e.g., top and bottom
- the source and direction of the conditioning airstream
- proximity to heating and cooling sources (motors, lights etc.)
- adjacency to doors, windows, skylights, and the impact of their use
- operational requirements: how long doors will be open, how many people going in and out, traffic patterns
The whole area should be monitored for a period of at least 24 hours using EDLMs (electronic data logging monitors). Following table shows how the data should be recorded for an OQ test.
Here are a few guidance documents to further your research:
1. World Health Organization (2015). Technical Supplement 8 - Temperature Mapping of Storage Areas.
2. USP (2018). USP41-NF36 <1079>. Good Storage and Distribution Practices for Drug Products
3. ISPE (2021) Good Practice Guide: Controlled Temperature Chambers 2nd Edition
