Building management systems (BMS) monitor and control power systems, fire systems, security systems, air systems, etc. The air system captures the temperature and humidity, and then it adjusts the operations to maintain the given settings. The loop system is automated and self-correcting.
However, good industry practice (GxP) requires a different and independent environmental monitoring system or a central monitoring system. It does not have control loops. Instead, the primary purpose is to collect and record environmental data to prove a drug’s safety and efficacy. For example, cleanrooms have strict temperature, humidity, pressure, pressure differential, CO2, and particle requirements for product quality. Additionally, the systems include an alarm, which activates when environmental conditions deviate from the user’s programmed settings. Similarly, independent loggers and indicators collect data for containers, boxes, freezers, and refrigerators.
Sensor calibration is essential in monitoring systems since sensors lose their accuracy, sensitivity, and precision over time. This loss of accuracy is known as “drift.” After one year, a repeat calibration is recommendable to certify that the sensor's accuracy is still within specification.
Calibrating a sensor compares the unit to reference equipment. The test is repeated with different temperatures and must be within a given tolerance. The calibration standard operating procedures (SOP) can be accredited to ISO 17025 standards. Regular audits and intercompany tests are hosted to ensure reliability.
Thermal Mapping is a part of qualification, which is a part of validation.
Both GMP and GDP require the drug storage area/container be qualified. Qualification means that the system works correctly according to specified requirements. To start, qualified personnel places several calibrated sensors throughout the room/container to measure temperatures and humidity throughout the room/container. The goal of thermal mapping is to identify the cold, warm, and humid locations so they can be adjusted (like sealing a door to prevent airflow) or have sensors permanently placed for monitoring during operation. This includes capturing changes when doors are opened and shut and the rate of change.
Supply chain elements that need qualification include storage facilities, cold rooms, containers, insulated boxes, reefer trucks, vans, data loggers, software for evaluation and archiving, etc.
Validation is quite simply described as a process working as intended. The following are the steps of validation in the simplest form:
- Define the expected results
- Test the results
- Document the results
For example, to store products in a warehouse, you need qualified employees, systems, and equipment to support the process, all of which need validation. Validation is only possible if all used elements are qualified.
All You Need to Know About Temperature Mapping
In both preparation and maintenance of product storage or transport, your room or container must be mapped to ensure products are measured accurately, and the space is suitable for storage.