A Commercial OOS Predicament

It feels like the sky is falling. Two months prior to expiry we have an OOS for our commercial oral antibiotic tablets—one of the degradants exceeded the upper specification limit at our 18-month interval. The sample was pulled as scheduled on October 25th and the next pull will be made at the expiration interval on 28-Dec-2022. The Degradation Impurities by HPLC assay was completed and verified within a week of the pull, but the OOS news was not expected. The laboratory quickly investigated, and not only did they find no error, a second analyst confirmed the original with both replicates, so they are expected to formally close out their documentation tomorrow, which will be our official date of recognition.

Historical data shows that this degradant increases linearly over time, as did this batch. It is a process-controlled impurity, so it started at the same magnitude and increased roughly at the same rate as other batches through the 12-month interval but has now popped over the line. Meanwhile, we have another commercial batch on stability from the same year of manufacture that hit the 12-month interval three months ago and showed marginal results. We also have two batches from the previous year that both expired within specifications.

While the plant is evaluating manufacturing batch records, QA is checking for any uptick in complaints, and we are checking for any potential environmental causes or anything obvious—like a hole in the bottles or something. This is a frequently manufactured product with multiple batches on the market and in distribution.
Assuming we find no smoking gun for this batch, what is the next course of action you would recommend? Can we avoid a recall?

The clock demands that the results be reported to the Regulatory Authorites with actions and conclusions to date. They may ask for a decision to recall, but it could be worth emphasizing the on-going quality/manufacturing investigations, especially if they can be wrapped up in a very short period of time. What would you do if this was your situation?