When developing a new medical device, packaging is often an afterthought. However, rushing through the sealing portion of your packaging validation could waste valuable time and resources. ISO 11607-2 gives a framework for this process, but there’s a lot of room for interpretation. In this blog, we’ll walk you through the primary steps of the sealing validation process and the activities associated with them.
Step 1. Installation Qualification (IQ) – Ensuring equipment is installed and functions properly.
Step 2. Operational Qualification (OQ) – Confirming that the sealing process performs reliably across its limits.
Step 3. Performance Qualification (PQ) – Demonstrating that the process remains consistent in real-world production.
Step 1: Installation Qualification (IQ) – Laying the Foundation
Before any validation testing begins, it’s critical to ensure that the sealing equipment is properly installed and functioning correctly.
What is IQ?
As defined in ISO 11607-2 (Section 3.5), IQ is the “process of establishing by objective evidence that all key aspects of the process equipment and ancillary system installation comply with the approved specification.” At a high level, the IQ checklist is:
✅ Check for correct equipment specifications (model, size, configuration)
✅ Verify appropriate environmental conditions (temperature, humidity, cleanroom requirements)
✅ Check utilities (air pressure, electrical, calibration, etc.)
✅ Review maintenance and calibration records to confirm accuracy
“IQ is usually a quick process. If the equipment is installed in a controlled environment and meets calibration and utility requirements, you can move forward efficiently” explains Respecki.
Design of Experiment (DOE) – Setting the Stage for Success
DOE is arguably the most important step in sealing validation, but it is not explicitly captured in ISO 11607-2. However, at PCL, we perform a DOE for every sealing validation that we execute. Identifying the correct sealing window ensures that downstream validations go smoothly, preventing unnecessary rework.
“If you rush through the DOE, you might end up with incorrect parameters,” Respecki cautions. “That leads to failed validations, wasted materials, and a lot of frustration down the road.”
You can first begin the DOE with an edge of failure exercise.
Edge of Failure Study
Steps:
Upper Bound Testing:
1. Start at an effective sealing temperature.
2. Increase temperature by 10°F (5°C) increments until the material melts.
3. Record the failure temperature as the highest functional temperature.
Lower Bound Testing:
1. Start at an effective sealing temperature.
2. Decrease temperature by 10°F (5°C) increments until little adhesive transfer is observed.
3. Examine seals for inconsistencies and establish the lowest functional temperature.
Range Finding Exercise
Steps:
1. Select temperature and dwell time combinations within safe limits.
2. Keep pressure constant to minimize variables.
3. Use vacuum if needed to stabilize the product.
4. Adjust dwell time or volume as necessary.
5. Select an appropriate number of recipes based on the materials of construction.
6. Fabricate multiple seals at each selected recipe*
*At PCL, we define a recipe as a unique set of sealing parameters, which includes time, temperature, and pressure.
Visual Scoring
Steps:
1. Examine each seal using a 0-5 scale:
• 1 = Poor (incomplete adhesion, open seals).
• 5 = Perfect (uniform seal, full adhesive transfer).
2. Example score of 3: ~50% adhesive transfer.
3. Record visual scores for each sample.
Seal Strength Characterization Plot
Steps:
1. Conduct seal strength testing per ASTM F88.
2. Record seal strength and corresponding visual scores.
3. For each recipe, plot average seal strength vs. visual score to determine the ideal sealing parameters.
4. Analyze the trend by identify where the curve levels off (nominal parameters).
5. If the results are unexpected:
• Reassess the sealing window and fabricate more samples.
• Inspect sealing equipment for issues. Check for equipment wear, thermocouple placement, or inconsistent heat distribution.
Establishing the Sealing Process Window
Steps:
1. Account for Calibration Tolerance & Equipment Variation:
• Temperature: ±5°F
• Dwell Time: ±0.5 seconds
• Pressure: ±5 psi
2. Define Low, Nominal, and High sealing parameters.
3. Validate parameters in Operational Qualification (OQ).
4. Document the final process window.
By investing time on DOE activities upfront, you’ll simplify downstream validations and save considerable time and potential headaches.
Step 2: Operational Qualification (OQ) – Testing at the Limits
At this step of validation, you’re confirming that the equipment produces good seals even at its worst-case limits. This can prevent unexpected failures during production. Testing at this step includes:
• Sealing at the lowest and highest parameters
• Simulating real-world equipment fluctuations
• Testing for integrity: Visual Inspection (ASTM F1886), Seal Width (ASTM F2203) , Dye Leak Testing (ASTM F1929 or F3039), Aseptic Opening (Per ISO 11607), Seal Strength (ASTM F88)
Step 3: Performance Qualification (PQ) – Confirming Stability
Performing a PQ ensures your sealing process is stable and capable under routine conditions.
Testing at this stage includes:
• Sealing three production lots at nominal parameters.
• Including product to evaluate how device size and weight impacts the seal.
• Performing the same testing as in OQ to confirm seal integrity.
So, when do you need to revalidate the sealing process?
You may need to revalidate when changes are made to the packaging system, such as material or equipment adjustments. “Even small changes – like moving your sealing equipment- can impact your validation” Respecki explains.
Although ISO 11607-2 outlines the typical approach to a sealing validation, there are still many nuances to be addressed. Taking a conservative approach could save you time and resources. If you are in need of help with sealing validation project, PCL’s expert team of packaging engineers are happy to help!
Need expert help with sealing validation? Contact PCL today.