Expiration Date Of Drugs: Is Effectiveness Decreasing?

The expiry date of medicinal products is the date until which the stability of the medicinal product in its original packaging, unopened or untouched, and stored under appropriate conditions, is guaranteed.

There is a legal maximum expiration date of five years. However, it can also be less than five years and in that case there is a mention on the packaging.

What is the expiry date of medicines?

The actual meaning of the expiration date of medicines corresponds exactly to the period in which the manufacturer assures, and with rigorous scientific studies, that the product retains 100% of the active ingredient.

The expiry date of medicines is usually indicated in the format MM/YYYY. That is, two digits indicating the month and four digits indicating the year, separated by a slash.

The actual due date is the last day of the month that appears. The expiration date thus refers to the expiration of the guaranteed stability and efficacy (Spanish link). When a medicine reaches its expiration date, the properties of the medicine may change.

What does the stability of a drug depend on?

The stability of a drug depends on several factors, including those listed below.

Temperature

One of the factors that has the most influence on the shelf life of medicines is the temperature. Therefore, it is always recommended to keep them in a cool, dry place. In addition, you must ensure that they do not undergo sudden temperature changes.

Pharmaceutical format and the expiration date of drugs

If the pharmaceutical format of a drug is liquid, such as solutions, suspensions or syrups, then they are not as stable as the solid forms (link in spanish).

In the case of solid dosage forms, you should pay attention to any change in color or physical appearance. However, these changes are usually a sign of degradation of the excipient and not of the active ingredient.

Multidose medicines are medicines that you open several times to administer them, such as a syrup or eye drops. This may alter the stability of the drug and pose potential risks to the efficacy and safety of the drug.

Therefore, the expiration date after opening no longer determines the validity period. The period is usually shorter, and the package insert provides the necessary details.

To remember when you opened it, it is recommended that you write the date it was opened or reconstituted on the package. In any case, it is better to throw away the remaining medication after the treatment is completed.

When it comes to eye drops, and the validity period after opening is not stated on the packaging or leaflet, the recommendation is a maximum of four weeks.

Does it still work a few months later?

According to experts, it is possible that medicines lose their effectiveness after the expiration date specified by the laboratory. However, if you observe the expiry date, you can be sure that the medicine has not lost its effectiveness and that there are no potentially toxic substances in it.

In general, it should not be a problem to take a medicine whose expiry date has passed two months ago. However, it is one thing if the expired medicine is more or less effective, and another if it becomes toxic.

What Does Science Say About Drug Expiration Dates?

In recent years, research has been conducted in several countries on the purity and efficacy of medicines after their expiry date. However, it is important to keep in mind that the storage conditions of the drugs in the study were always kept under optimal conditions.

The results were surprising, as a high percentage of the drugs retained at least 90% of the active ingredient after the expiration date. By the standards of minimal effectiveness or efficacy that researchers expect, this is an acceptable figure.

How to store your medicines

In order for a medicine to remain in optimal conditions of safety and efficacy until its expiration date, you must store it properly. Please note the following instructions:

• Store it in a cool, dry place without sudden temperature changes.
• Do not place them next to electrical appliances. That way you avoid electromagnetic fields.
• Keep them in their original packaging.
• If you are using a pill box, prepare it for only a few days.

Conclusion

Most studies show that consuming over-the-counter medications poses no real danger to your health. However, it is most advisable to avoid taking expired medications to avoid possible side effects.