Hi Fidrych,   I can certainly understand your concern about discarding unused medication.  With the costs of our healthcare coverage and medications on the rise, it doesn't seem to make sense to throw away something that still looks good enough to use.  However, the shelf life for Pulmicort Respules is two weeks once the foil bag has been opened. This is the amount of time the manufacturer can guarantee the medicine will work according to their claims.    Keep in mind that some medicines lose their potency over time, and other medicines can become unstable over time.  This is why manufacturers give their medicines an expiration date and a shelf life.  The choice to discard or use out dated medincie is entirely up to you.  If you would like more specific information about Pulmincort Respules, please talk to your doctor or pharmacist.   :)