Things to Keep in Mind When Buying Validatable Sealer Equipment
Based on FDA CFR Title 21, Part 820.75, "where results of a process cannot be fully verified by subsequent inspection and test, the process shall be validated with a high degree of assurance and approved according to established procedures." Since the outcome of a sealing process cannot be fully verified, the medical packaging industry validates sealer equipment. This is why sealer equipment manufacturers have in their product catalog list a medical sealer version that can be validated.
In my experience working with medical sealers, designs have come a long way trying to meet all the requirements and standards in the medical industry. Things like password protection, audible alarms, calibration ports, operator lockouts, and data collection are now becoming more standard options in medical sealer equipment designs.
Even with all these improvements there are things you should keep in mind when buying medical sealer equipment to guarantee that it is 100 percent validatable.
Stabilization time is not the same as reaching the temperature set point. Remember that the temperature is typically monitored on a single point and just because the sealer has reached the set point, it does not mean the temperature is equally distributed across the platen.
A temperature controller in which the alarm limits are based on +/- X degrees from the set point may not be the way to go. Let's say that you have validated a sealing process where your temperature window is 230° to 240° Fahrenheit with a nominal set point of 235°; this means that the temperature controller will be set up to 235° and since the controller works with +/-, it will be set up to 5°. Now you are ready to go and the sealer will alarm in the event the temperature goes below 230° or higher than 240°. This is a true statement as long as the set point is not changed. In the event you need to change the set point within the validated range, then with this design, the sealer may allow sealing outside of the validated window before it alarms. In this same example, if there is a need to lower the temperature from 235° to 233° you may think that it is OK to do so because the process was validated to a lower temperature than 233°. This in fact is a correct statement, but what you do not know is that the temperature controller is still set at +/- 5°. This means now that the sealer will alarm in the event the temperature goes below 228° or higher than 238°. Now, the low temperature alarm limit in the temperature controller is below the validated window. In other words the temperature controller has changed the alarm limits based on the new temperature set point.
Instead of this design, ask for a temperature controller or have the PLC programmed to have fixed alarm limits in which they do not change at all and prevent you from setting a temperature outside the fixed limits.
There are more things to take in consideration for sure, but this one is still very common to see even on newer designs.
Charlie Rivera, CPP