same batch number showing up at two unrelated vendors. that is not a coincidence
same batch number showing up at two unrelated vendors. that is not a coincidence — a position I have arrived at slowly and would like tested. Started buying small deliberately, tested every lot for the first four, then stopped testing every lot because there was nothing to find. Kept a spreadsheet of quoted versus…
The wider-market rows in the directory carry a band and a report count and nothing else, deliberately. Anything more would be manufacturing precision that the evidence does not support.
a supplier that answers method questions in writing has already told you a lot
That reads as a recommendation and the source pages deliberately are not. They are a record you use to make your own decision.
Did the lot code on the vial match the paperwork?
Which service did the testing, and did you pay for it yourself?
The wider-market rows in the directory carry a band and a report count and nothing else, deliberately.
Adding the practical version: ask for lead time, minimum quantity and the batch record in the same message. Three answers, one email.