Verification of Base Values of refrigeration and vacuum system capabilities

Verification of Base Values of refrigeration and vacuum system capabilities in freeze dryer. Verifying the base values of refrigeration and vacuum system capabilities in a freeze dryer is crucial to ensuring compliance with specified parameters. This process assesses whether the system can achieve the necessary cooling, heating, and vacuum conditions for optimal freeze-drying performance.

Proper verification helps manufacturers confirm system efficiency and reliability before operation, reducing risks associated with inadequate temperature control or vacuum performance.

Understanding these parameters is essential, particularly in areas such as temperature overshoots (Impact of Temperature Overshoots During Lyophilization) and vacuum performance verification (Vacuum Performance Verification: A Comprehensive Procedure). This guide outlines the necessary test documents, implementation steps, and acceptance criteria required to ensure the system meets the required standards.

Purpose: The purpose is to check that the refrigeration and vacuum system capabilities meet the specification.

Documentation Required

Proper documentation is crucial in the verification process of refrigeration and vacuum system capabilities in freeze dryers. It ensures compliance with industry standards, maintains traceability, and provides a reference for troubleshooting and future assessments. Below is a detailed breakdown of the required test documents:

1. Test Documents

Test documents serve as the foundation for verification. They contain all necessary records related to the performance of the refrigeration and vacuum systems. These documents must be prepared, reviewed, and stored properly for regulatory compliance and quality assurance.

2. Document Name

Each document must have a clear and specific name that identifies its purpose. This helps in easy retrieval and prevents misinterpretation. Examples of document names include:

• Refrigeration System Performance Validation Report
• Vacuum System Capability Test Report
• Freeze Dryer Operational Qualification (OQ) Report

3. List of Parameters

The list of parameters includes all critical factors being assessed during the verification process. Some key parameters may include:

• Temperature Control: Minimum and maximum temperature values, cooling/heating rates
• Vacuum System Efficiency: Ultimate pressure levels and evacuation times
• Condenser Performance: Cooling time and achieved temperature

These parameters help ensure that the freeze-drying unit is functioning within the required specifications.

4. Batch Report

A batch report provides data from specific freeze-drying runs, detailing how the system performed under test conditions. It may include:

• System response times
• Any deviations or alerts during the process
• Achieved temperature and vacuum values compared to expected results

Batch reports are essential for understanding trends and detecting potential system inefficiencies.

5. Screen Printouts

Screen printouts from the SCADA system or other monitoring software are required to visually document real-time data. These printouts capture:

• Temperature and vacuum trends over time
• System alerts or warnings encountered during the process
• Final verification graphs confirming system compliance

Marking these printouts with the “Qualification Document” stamp ensures that they are officially recognized as part of the validation process.

6. Document Number

Every document must be assigned a unique identification number to facilitate tracking and organization. This numbering system prevents confusion and ensures that documents are referenced correctly in future audits or inspections.

7. Version Number

Since test procedures may be updated over time, each document must have a version number to indicate which iteration is being used. This is essential for:

• Ensuring all testers follow the most current procedure
• Avoiding outdated methods that could lead to errors
• Maintaining regulatory compliance in audits

8. Number of Pages

The total number of pages in a document must be recorded to ensure completeness. If a column for “Number of Pages” is left blank, it indicates that the listed documents should be attached to the qualification binder.

Conclusion: Accurate documentation is essential for verifying the refrigeration and vacuum system capabilities of a freeze dryer. It provides a structured approach to testing, ensures compliance with regulatory standards, and serves as a reference for performance validation.

For a detailed guide on freeze dryer performance verification, visit Freeze Dryer Periodic Performance Verification.

Note: If column “number of pages” is blank, the listed documents, which contribute to the determination of the test result, must be attached to the qualification binder (see B: Attachments). Please mark the test documents and printouts on the first page with the “Qualification Document” stamp.

Required Instrumentation and Auxiliary Means

Proper verification of the refrigeration and vacuum system capabilities in a freeze dryer requires the use of specific instruments and auxiliary equipment. These tools help in accurately measuring system performance, ensuring that all parameters meet the required specifications. Below is a detailed breakdown of the key components necessary for the verification process. Type of Equipment, Type, model/version number Serial Number, Calibration valid until

1. Type of Equipment

The type of equipment refers to the specific tools and instruments required for testing and verifying the performance of the freeze dryer. These instruments are carefully selected to ensure accuracy and reliability in measurement. Some commonly used equipment includes:

• Digital Temperature Sensors: Used to measure temperature changes in the refrigeration system and condenser.
• Vacuum Gauges: Essential for monitoring pressure levels and verifying evacuation efficiency.
• SCADA System: Used for real-time data monitoring, logging, and screen printouts.
• Thermocouples: Placed at different points to measure heat transfer efficiency.
• Pressure Transmitters: Ensure precise vacuum pressure measurement in different sections of the freeze dryer.

The use of calibrated and well-maintained equipment is crucial for obtaining valid results. Learn more about temperature control in freeze-drying processes here.

2. Type, Model, and Version Number

Each piece of equipment used in the verification process must have a specific type, model, and version number recorded. This ensures traceability and allows for consistency in testing procedures.

For example:

Equipment Type	Model/Version
Digital Vacuum Gauge	VG-5000X / Ver. 2.1
Temperature Sensor	TS-Pro / Ver. 3.2
Data Logger	DL-700 / Ver. 1.5

Recording this information helps in:
✔ Ensuring that only approved and compatible instruments are used.
✔ Avoiding errors caused by outdated or incorrectly configured equipment.
✔ Facilitating equipment maintenance and replacement planning.

For guidance on verifying temperature accuracy, check pre-study qualification of thermocouples here.

3. Serial Number

Each instrument has a unique serial number that distinguishes it from other similar devices. This number is crucial for:

🔹 Tracking the history of use and past calibrations of the equipment.
🔹 Ensuring the correct instrument is used during validation.
🔹 Avoiding mix-ups between similar models in the facility.

For example:

Equipment	Serial Number
Digital Vacuum Gauge	12345-VG
Temperature Sensor	TS-6789

Serial numbers are typically recorded in validation documents for future reference.

4. Calibration Valid Until

All measuring instruments must be calibrated regularly to ensure accuracy and reliability. The “Calibration Valid Until” date specifies the last date before the equipment requires recalibration.

✅ If the calibration date has expired, the instrument cannot be used for verification.
✅ Regular calibration helps in reducing measurement errors and maintaining compliance with industry standards.
✅ Calibration records should be updated and attached to qualification documents.

For example:

Equipment	Calibration Valid Until
Vacuum Gauge	30-June-2025
Temperature Sensor	15-Dec-2024

It is essential to follow a strict calibration schedule to maintain data integrity. For more insights into vacuum system performance, visit vacuum performance verification here.

Conclusion: The verification process of refrigeration and vacuum system capabilities depends on accurate instrumentation and auxiliary equipment. Recording details such as equipment type, model, serial number, and calibration validity ensures reliability and compliance with validation protocols.

Acceptance Criteria: The system capabilities should comply with the specified values.

Implementation

Possible instructions and notes in the test documents are to be considered. The freeze drying unit must be switched on, and all supply media must be connected and present. No failure messages, which have an impact on the implementation, are displayed on the SCADA system. The tester must be appropriately assigned to the freeze drying unit and the SCADA system.

Performance of Test

The verification of the base values takes place in accordance with the test document LOXYZ-001B-1. Please enter the freeze-drying recipe that is described in document LOEE1507-001A-1 and start the process. The values will be verified with a clean and empty freeze drying unit.

This test is used to stress the system as much as possible and to verify that the system is able to achieve the specified values. This recipe does not reflect any production cycles. For example, it is not possible to achieve -68°C within 1 minute; therefore, a failure message might occur (e.g., “Failure Temperature deviation during segment”). This does not have an influence on the test result.

The test run can be stopped if the system has achieved the final vacuum. After the test has been finished, the tester has to generate the screen printouts. Therefore, the tester has to set the cursor in the required position in the graph to verify the results.

Result of Tests

The verification process includes evaluating the cooling, heating, and vacuum performance of the freeze dryer. The results confirm whether the system meets the required specifications. Below is an explanation of the key test parameters:

Cooling and Heating of Heat Transfer Medium

Acceptance criteria	Specified	Actua	Test result
Final temperature (minimum value)	≤ -60. °C	-60.6 °C	Pass
Cooling rate of the heat transfer medium from 20° to -40°C	≤ 50 min.	24.02 min.	Pass
Heating rate of the heat transfer medium from -40° to 20°C	≤ 60 min.	23.60 min.	Pass
Final temperature (maximum value)	≥ 65 °C	72.7°C	Pass

This section assesses the freeze dryer’s ability to regulate temperature effectively. The system must achieve the specified minimum and maximum temperatures and maintain efficient cooling and heating rates.

• Final Temperature (Minimum Value): The system successfully reached -60.6°C, meeting the requirement of ≤ -60°C.
• Cooling Rate: The heat transfer medium cooled from 20°C to -40°C in 24.02 minutes, well within the 50-minute limit.
• Heating Rate: The medium was heated from -40°C to 20°C in just 23.60 minutes, significantly faster than the 60-minute requirement.
• Final Temperature (Maximum Value): The system exceeded the required minimum of 65°C, reaching 72.7°C, ensuring optimal thermal performance.

These results confirm that the system’s heating and cooling efficiency is optimal, which is crucial for maintaining consistent freeze-drying cycles. Learn more about shelf heating and cooling rate verification here.

Evacuation of Empty Freeze Drying Unit

Acceptance criteria	Specified	Actual	Test result
Ultimate pressure	≤ 0.005 mbar	0.003mbar	Pass
Evacuation time from 1000 to 0.1 mbar	≤ 40 min.	16.14 min	Pass

This section verifies the vacuum system’s capability to achieve and maintain low pressures efficiently.

• Ultimate Pressure: The system achieved a vacuum of 0.003 mbar, better than the specified limit of ≤ 0.005 mbar.
• Evacuation Time: The system reached 0.1 mbar from 1000 mbar in just 16.14 minutes, far below the 40-minute threshold.

These results confirm that the vacuum system is operating efficiently, ensuring a reliable freeze-drying process. For an in-depth look at vacuum performance testing, refer to vacuum performance verification here.

Condenser Final Temperature and Cooling Time

Acceptance criteria	Specified	Actual	Test result
Condenser ultimate temperature	≤-75°C	-76.1°C	Pass

The condenser’s ability to achieve the required low temperatures is essential for trapping sublimated ice efficiently.

Condenser Ultimate Temperature: The system reached -76.1°C, surpassing the required ≤ -75°C, ensuring effective ice condensation.

A properly functioning condenser is crucial for maintaining process efficiency. To learn about common issues related to refrigeration systems, check refrigerating compressor failures here.

SummaryThe test results confirm that the refrigeration and vacuum system capabilities of the freeze dryer meet the required specifications. The system efficiently regulates temperature, maintains vacuum conditions, and ensures effective condensation. This verification process is essential for preventing operational failures and optimizing freeze-drying performance.

For further insights into freeze-dryer performance verification, visit freeze dryer periodic performance verification here.

Summary

The verification process involves the following steps:

• Reviewing test documents and necessary instrumentation.
• Ensuring the freeze-drying unit is properly set up and operational.
• Performing the test according to documented procedures.
• Measuring refrigeration and vacuum system capabilities, including temperature control, cooling rates, and vacuum evacuation efficiency.
• Comparing actual values against the specified acceptance criteria.
• Recording results and generating necessary screen printouts for documentation.

This verification confirms that the freeze-drying system functions within its design specifications, minimizing potential failures during real-world applications. Additionally, regular periodic performance verification (Freeze Dryer Periodic Performance Verification) is recommended to maintain system reliability over time.

Conclusion

The verification of refrigeration and vacuum system capabilities in a freeze dryer is essential for maintaining process reliability and efficiency. Meeting the specified acceptance criteria validates the system’s ability to sustain required conditions, ensuring optimal product quality and performance. Continuous monitoring and verification procedures, such as surface roughness checks (Check of the Freeze Dryer for Surface Roughness), further enhance system performance and longevity.