Frequently we get calls from medical device companies telling us that they need to validate their processes, either because a customer, a partner, the FDA, or another regulatory body has cited them during an audit for lack of process validation. In many of these situations, the statement of work presented to us includes IQ, OQ, and PQ for the equipment and product, but not validation of the process. Process validation cannot proceed without calibrated and qualified/validated equipment, but that is only the beginning.
Manufacturing of a medical device consists of a series of processes. Examples of manufacturing processes include welding, injection molding, passivation, sterilization, labeling, and packaging. Most medical device manufacturing will include other processes as well. Validation of each process involves producing documented evidence that the process in question consistently produces results that conform to predetermined specifications. For example, the output of a welding process will be a specified weld strength as determined by using a test method. In this example, the intent of process validation is to demonstrate that when the weld is produced with inputs (angle, polarity, current, voltage, etc) in specified ranges, the weld strength will consistently meet the required, predetermined strength. In addition, the test method must be validated prior to using it to measure the output of the process during process validation.
We have seen instances where medical device companies have received a 483 for lack of, or inadequate, process validation. The company has responded by performing only equipment validation. This response has lead to a Warning Letter. To prevent this from occurring, medical device companies need to be aware of the requirements for process validation. These requirements may be found in 21 CFR 820.75 and in ISO 13485.