That's an interesting bit of research to be done.
Some meds really don't ever "go bad" if they're stored properly, even though they have expiration dates. It's my understanding that they have to
have an expiration date of some sort, so if it doesn't really GO bad, they will have 5 years on the expiration just to cover the legal bases.
Some meds deteriorate over time but don't become toxic, so you just have to titrate the dose to match.
Some meds go bad with a vengeance and become somewhat to very toxic.
Someone with more time than I have should find out what are good/bad meds for the bugout kit.
Aspirin is one that becomes somewhat toxic, and tetracycline becomes very toxic. But I don't know about ibuprofen or doxycycline.