The point is we don't necessarily know, or know to the degree of certainty the FDA requires, how many of these things degrade. Perhaps in certain conditions, they degrade at one rate, but in other conditions (such as a temperature difference), they degrade at a different rate. Testing how drugs perform years after production in multiple different scenarios is necessarily time consuming, because it takes at least that much time to be sure.
I'm a test engineer. Highly accelerated life testing (HALT) can probably be used to closely approximate the shelf life of medicine. You need to look at the parameters that cause degradation (humidity, temperature, light exposure, etc). HALT the samples at different temperature/humidity/lighting extremes and use mass spectrometry to check purity. Use the data to create an algorithm that approximates the product lifetime and then correlate the results with actual shelf life for verification.
Unfortunately, ALT is not a solution, because it's not accepted by FDA, except as a temporary measure.
Any drug submission that supports shelf life via ALT data will be expected to also say "and we're doing real time testing to support this", and FDA will expect the follow up real-time data.
Then perhaps the solution is for the FDA to allow HALT testing. Having said that, I imagine there is little incentive for pharma companies to willingly extend the shelf life of their products - perhaps the real solution is for the FDA to actually require HALT testing.
I think the real thing here is, "Better safe than sorry". It's fine to use things like HALT testing initially to say, "this drug should be effective for 8 years" so that folks can get it to market before 8 years have passed.
But if, in reality, that drug only lasts for a strong 5 years, after which time it loses effectiveness, especially in high humidity or with high UV exposure. We could catch this with real-time tests and adjust accordingly - before it actually affects the general public's health.
The largest barrier to accelerated life testing right now is that we really don't know all the mechanisms that cause degradation (or understand their impact on stability). There are many lab instruments that already provide HALT metrics on how stable a drug sample is expected to be under different conditions. And the Arrhenius and Eyring equations are useful for empirical modeling. These tools are great for quickly identifying when formulations are unstable. But it's very difficult to say with certainty (at least in the pharma world) that something will be stable for X years unless you actually test it for X years.
For the vast majority of manufactured products, HALT makes sense because any uncertainty that remains after testing is not likely to harm users. But with some of these drugs, any uncertainty, even after HALT, could cause major problems for users. And it seems that the FDA is unwilling to accept that risk. But as far as I know, the FDA is actively seeking methods for performing HALT that produce accurate and repeatable results.
I see medicines in foreign countries wrapped in some kind of aluminum foil. Will that prolong the life of the medicine given there is no oxygen to react?
Given the amount of money spent on medicines, I really think there is a good moral business case to identify the correct expiration dates and save money for people.
We just went through the Health care ordeal. Money saved anywhere is money saved for people who desperately need healthcare to work for them.
Except the medicines themselves aren't expensive. The prices are that high because the pharma companies demand it, because of all the tests, which are their main source of income. That is why prices in the US are so much higher than elsewhere (because of the political power of lobbying and cultural acceptance of price screwing the public on medical things).
Given that it's the very same party that would be doing the testing for expiration dates, I kind of doubt they would research this out of the goodness of their corporate hearts. Effectively the same outcome could be realised without the effort of extra testing anything: by just lowering the price of medicine a bit; big pharma would make less money, the public would have more medicine for cheaper.
There may be other ways to approach this from a moral point of view. High prices for medicines are defended on the basis of high research costs, not high manufacture costs.
A case could be made for legislation that obliges free replacement of out of date medication for the original purchaser, perhaps with a small surcharge.