In the event that a defect spike occurs during the validation phase, I think that the first thing that should be done is to formally document the defect either through deviation or non-conformance instead of continuing normally. Continuing to validate with known defects could jeopardize the validation data and would create a significant regulatory issue in the future. At the same time, I will be starting a root cause analysis with the vendor regarding the production changes, batch record, and shipping environment. To not stop the project altogether during this time, the incoming inspection can be made tighter (i.e., increased sample size or temporary 100% inspection) while actively controlling the defect.

Furthermore, having only one validated vendor creates a risk in these situations, therefore I would begin the qualification of a second vendor, running in parallel with the current vendor, in order to eliminate the long-term reliance on one vendor. While this may seem to be a lot of extra work in the beginning, it will provide me with the flexibility to use the second vendor if the issues arise again. Also, open communication with both vendors and internally will be important to ensure that all parties involved understand the expectations and risks. The objective will be to balance progress against data integrity. Would you find it acceptable to continue validation with tighter controls if defects exist, or should validation be put on hold until the issue has been completely resolved?

The first step is to confirm the defects are actually coming form the vendor and not form testing or handling. Once it is verified that it is solely from the vendor, and this is the only qualified vendor, switching is not a realistic option. I would quickly contact the vendor to identify the root cause. The issue may be regarding their manufacturing process or a new material, which can be a quick fix. 

While there is ongoing communication with the vendor, the inspection should be increased because it must be ensured that no defective packages move forward. Communication on this matter is also very important. The issue should be escalated early so stakeholders understand the risk to the timeline. It may also be worth it to start qualifying a backup vendor to reduce future risk. 

Overall, the goal is to fix the root cause while putting short term controls in place so validation can continue. 

At what point would you decide that the vendor is no longer reliable enough and you must move to a new one?

If a vendor shows unusual packaging defects during validation, the team should pause and investigate instead of continuing. Defects like pinholes or tears can affect product safety and invalidate results. The issue should be reviewed with the vendor to find the root cause and implement corrective actions. At the same time, the team can use temporary controls like increased inspection or separating defective lots. It is also important to start qualifying a backup supplier to reduce risk. Strong communication between teams will help make fast and safe decisions. The project should only continue once the issue is controlled and quality is assured.