A warehouse environment may be subject to regulatory compliance, which makes validation and monitoring necessary.
The critical parameters that need to be monitored are usually temperature and humidity. The parameters cannot exceed certain limit values and the variations need to be documented.
After manufacturing and before the dispatch of a pharmaceutical / food product it needs to be stored in a controlled environment.
The FDA regards Mean Kinetic Temperature (MKT) as a calculation that will show if a product has exceeded storage conditions. MKT can also be used to determine if storage, handling, shipment, etc. have affected the shelf life of the product. The MKT is a calculated fixed temperature that simulates the effects of temperature variations on the product over a period of time. It expresses the cumulative thermal stress experienced by a product at varying temperatures during storage. In addition to MKT it is recommended that min. and max. values are calculated including a description of the place and time of occurrence.
Some of the challenges when validating a warehouse could be:
- To check the performance of a temperature controlled warehouse
- To determine the cold and warm zones of the warehouse
- To confirm pre-defined temperature / humidity ranges
- To identify and improve temperature / humidity equilibration
- To determine the highest temperature / humidity fluctuations within the warehouse
- To revalidate the location of the existing fixed sensors of the current monitoring system
- To calculate and document the Mean Kinetic Temperature
Ellab’s ValSuite™ Pro software calculates MKT according to these standards:
- USP chapter no. 1079: “Good storage and distribution practices for drug products.”
- ICH norm no. Q1A (R2) page 15.
A specified number of loggers are placed in the warehouse in pre-determined critical mapping points. The temperature mapping is typically performed over a minimum period of 48 hours. As an example, the method used for a warehouse validation should take the following points into consideration:
- Critical mapping points to include outside environment and unconditioned spaces near the measured area
- Sample rates should be at intervals of every 30 minutes
- In large areas or spaces it may be necessary to divide the total area in sections and position the specified amount of loggers/sensors in an ‘X’ pattern
- The data from the mapping activities may be evaluated for conformity or gap analysis
- All events and movements, including those that are inherent to warehouse operations, should be recorded
- All test results, observations, evaluations and recommendations should be documented
The frequency of the temperature mapping is a minimum of at least once a year. Additional temperature mapping may be required for changes such as conditions mentioned below:
- Change of temperature settings
- Changes made to the storage capacity
- New monitoring system
- New equipment installed that may impact the temperature and relative humidity
- If the continuous temperature mapping activities are interrupted (e.g. due to power failures or any event that may impair the continuous data collection)
- Extreme weather changes
- Warehousing standards or quality management system changes
- Any other changes made that could affect temperature/humidity
In areas with potentially high temperature fluctuations additional temperature recording devices must be strategically located:
- Near windows, ceilings and exits
- Skylights, air-blowers, ducts and A/C units
- Areas with high traffic movement and activities
- Near heat sources
The temperature mapping grid should have all temperature recording devices and loggers positioned at distances following the sensor’s capacity to efficiently measure the temperature changes across the entire warehouse. The mapping grid should allow the thermal mapping activity to capture both the hot and the cold zones. The distance between the sensors should ensure that the thermal mapping activity will be able to record and produce an efficient temperature profile of the warehouse.