Hello Yugen88,
The only way to know with 100% certainty is to subject at least 1 tablet, selected at random to qNMR or HPLC-MS. These are both high cost laboratory instruments. We do this on request.
We have a section on supply chain integrity which is really important with getting things online. https://fixhepc.com/supply-chain-integrity.html
Mylan make good medication. The trick is making sure Mylan made it.
If you want to post some photos I’ll compare them to a sample box we have in the safe.