Nobody said they need to find the absolute last day the drug expires before they can get it to market.
If it's a new drug and they can only say for sure that it lasts 6 months then put that on the label and ship it out. But assuming the drug will be out for 10+ years they should be continually testing the expiration date and updating as they've had more time to make that determination.
But like I said initially (and as you nicely pointed out) that costs money so why bother?
> If it's a new drug and they can only say for sure that it lasts 6 months then put that on the label and ship it out. But assuming the drug will be out for 10+ years they should be continually testing the expiration date and updating as they've had more time to make that determination.
This needs regulatory work. And this bring very little returns, so your regulatory resources are better spent somewhere else. There are other incentives in place.
If it's a new drug and they can only say for sure that it lasts 6 months then put that on the label and ship it out. But assuming the drug will be out for 10+ years they should be continually testing the expiration date and updating as they've had more time to make that determination.
But like I said initially (and as you nicely pointed out) that costs money so why bother?