The expiration date of a drug is the period during which the drug can be maintained at a satisfactory quality under the specified storage conditions. There are two ways to indicate the expiration date of a drug: expiration date and expiration date. For example, the expiration date is until September 2019, indicating that the drug can be used until September 30, 2019, and can no longer be used from October 1; the expiration date is until September 30, 2019, indicating that the drug can be used until September 30, 2019, and can no longer be used from October 1. For example, an expiration date of September 2019 means that the drug can be used until August 31, 2019 and can no longer be used from September 1; an expiration date of September 30, 2019 means that the drug can be used until September 29, 2019 and can no longer be used from September 30. Please use the drug within the expiration date of the drug under the storage conditions specified in the drug’s instructions.