Thanks for your question. I suspect the pharmaceutical companies put expiration dates on the packaging for a good reason. You can review our information on tretinion - this is from our info page:
Properly discard this product when it is expired or no longer needed.
Consult your pharmacist or local waste disposal company for more
details about how to safely discard your product.
As well, you can check with your pharmacist/drug store or you can contact the manufacturer.
Hope this helps and all the best, sue