Expiry refers to the date that every drug must carry, beyond which it should not be consumed by the patient. The expiry of the drug depends on composition and can have wide range, from few days to few years.

Expiry is an important parameter which all pharma companies want to track. Excessive production of a drug will increase inventory of the drug, and if it is not sold withing the stipulated time, the drug will expire and cause losses to the manufacturing company.