Expiration Of Medicines, When Does Their Effectiveness Decrease?

The expiration of drugs is the date until which the stability of the drug is guaranteed in its original container or container, not opened or manipulated and stored in adequate conditions.

Legally, there is a maximum expiration limit of 5 years. However, it could be less than 5 years and, in that case, it will be indicated on the packaging.

What is the expiration date of medicines?

The real meaning of the expiration date is the one that corresponds exactly to the period in which the manufacturer ensures, and demonstrates with rigorous scientific studies, that the product will retain 100% of the active ingredient.

The expiration of medicines can be expressed according to the 00/0000 format, that is, two figures indicating the month and four figures indicating the year, separated by a slash.

The actual expiration date is the last day of the indicated month. Therefore, the expiration date refers to the expiration of a guarantee of stability and effectiveness. When the expiration date of the drugs is reached, the properties of the drugs may be affected.

What does the stability of a drug depend on?

The stability of a drug depends on several factors, including the following:

Temperature

One of the factors that most affects the storage of a medicine is temperature. That is why it is always advisable to keep them in cool and dry places. In addition, you have to make sure that they do not suffer sudden changes in temperature.

Pharmaceutical form and expiration of drugs

If the pharmaceutical form is liquid, such as solutions, suspensions or syrups, they are not as stable as solid forms. In the case of solid pharmaceutical forms, you should look for any change in color or physical appearance, although these changes are usually a sign of the degradation of the excipient and not of the active ingredient.

Multi-dose medications are those that are opened multiple times for administration, such as a syrup or eye drops. This can alter the stability of the medicine and pose potential risks in terms of the effect and safety of the medicine.

Therefore, once opened, the validity period is no longer determined by the expiration date, but is described in the package insert and is usually shorter.

To remember when it was opened, it is advisable to write on the container the date it was opened or reconstituted.  In either case, it is best to dispose of the remaining medicine after the treatment is finished.

If it is eye drops and the validity time once opened does not appear on the package or package leaflet, it is recommended that it be a maximum of 4 weeks.

Could it continue to be effective a few months later?

According to experts, after the expiration date indicated by the laboratory, the drugs may be effective. However, when you respect the expiration date, you are sure that the drug has not lost activity and there are no potentially toxic substances in it.

Generally speaking, there may be nothing wrong with taking a drug that has expired two months ago. However, one thing is that the expired drug continues to be more or less effective, and another that it can become toxic.

What does the science say about the expiration of drugs?

Research on this topic has been carried out in recent years in different countries to check the purity and potency of drugs once the expiration date has been reached. However, it must be said that the drugs under study have remained stored in optimal conditions.

The results have been surprising, since a high percentage conserved at least 90% of its active principle after the expiration date passed, a figure considered acceptable by the standards of minimum effectiveness or potency expected by the researchers.

How to Store Medications

For a drug to remain in optimal conditions of safety and efficacy until the expiration date, it must be stored correctly. To achieve this, follow these guidelines:

• Keep them in their original container.
• If you use a pillbox, keep it for a few days.
• Store it in a cool, dry place without temperature fluctuations.
• Do not put them near electrical appliances. This way you will avoid electromagnetic fields.

In conclusion, although most studies state that consuming a drug that has expired a few months ago does not entail a real danger to health, it is best not to take it after its expiration date to avoid possible adverse effects.