United States Food and Drug Administration (USFDA) recommends that all
medications should contain 90-110 percent of the active ingredient that is
claimed on the label.
However, it is not mandatory for the manufacturer to
determine the potency of the medication post-expiration. This allows drug
manufacturers the flexibility to fix expiration dates without determining actual
long-term drug stability.
In other words, a drug manufacturer is only required to
provide evidence that a drug has full potency up till the expiry date the
company chooses to fix. The expiry date does not mean, or even indicate,
that the drug will cease to be effective after that, nor become harmful to
When Can Expired Medicines be Useful?
certain situations, outdated medicines may be required to be used in the
absence of other alternatives or due to economic reasons. A study has shown that
expired EpiPen auto-injectors that deliver epinephrine (a hormone secreted by
the adrenal glands that increase cardiac output and elevates blood glucose
levels) retains some of its potency even after the expiry. It is,
therefore, recommended that in the event of non-availability of un-expired
EpiPens, these could be used as long as no discoloration or precipitates are
apparent, since the potential benefit of using them is greater than the
potential risk of a suboptimal epinephrine dose or of no epinephrine treatment
Expiry Date vs Potency: Scientific Studies
The expiry date does not mean that the medicine loses its potency from that date and is no longer safe to take. In fact, the potency starts to decrease the moment it is manufactured and has no bearing on the expiry date. The expiry
date is determined on the basis of the date from manufacture up to which its
stability and shelf-life have been tested by the drug
couple of studies have unequivocally established that the potency of medication
is retained even after the expiry date:
US study found that 12 out of 14 drugs that were tested retained full
potency up to 28 years after the expiry date, of which 8 drugs retained
their full potency up to a staggering 40 years post-expiration!
US study, under the Shelf Life Extension Program (SLEP) of the Department
of Defense, USA, found that of a total of 122 different drugs that had
been stored under ideal environmental conditions, as per military
regulations, 107 (88%) had their expiry dates extended more than 1 year,
with an average extension of over 5 years, and a maximum extension of 23
Stability of Medicines
reference to stability, as a general rule, liquid medicine preparations such as
solutions or suspensions are less stable than solid forms such as tablets or
capsules. The stability decreases upon exposure to light (especially sunlight),
moisture, oxygen, and extremes of temperatures. Therefore, proper storage of
medicines in a cool and dry place is very important for increasing the
Safety & Toxicity of Expired
regard to safety and toxicity, the common belief is that expired drugs are
unsafe and toxic. However, there is little scientific evidence to support this
belief. Till date, only a single isolated report indicated that tetracycline
degradation products can cause a reversible type of renal tubular damage,
technically known as Fanconi syndrome. Although the lack of other reports of
toxicity from expired medication is reassuring, it should, however, be remembered that very
little research has been carried out in the area of toxicity of expired
Drugs for Which the Expiry Date is
are some drugs that have a narrow therapeutic index, meaning that even a small
decrease in pharmacological activity can have drastic clinical consequences.
Therefore, in case of these types of drugs, the expiry date should be
strictly adhered to
. Some of these drugs include the following:
the above-mentioned drugs, antibiotics should also not
be taken after the expiry date, as this can encourage antibiotic
Expiry Dates: Is There a Commercial Angle?
the stamping of expiry dates be a marketing strategy by pharmaceutical
companies, encouraging us to keep buying new medicines, throwing away unused
ones, thereby ensuring that their coffers are filled regularly? This is one way
of looking at it.
other way is that the expiry dates are very conservative to ensure that
medicines have their full potency. Moreover, if a pharmaceutical company had to
do shelf-life and drug stability testing for longer periods; it would slow down
pipeline of new and improved formulations due to obvious
What Should You Consider Before Taking
following factors should be taken into consideration before deciding to take
- Appearance of the
The actual appearance of the medicine is very important in the
decision-making process - whether to take or not. Medicines should not be
taken under the following circumstances:
tablets are brittle, have lost their sheen or have become discolored
an injectable becomes cloudy or a precipitate forms
expired ophthalmic solutions, the drug itself does not degrade, but the
preservative degrades, thereby encouraging microbial growth. So, if the
solution becomes cloudy (indicating microbial growth), it should be
- Length of Time From
lesser the time between the date of manufacture and time of final use, the
better will be the potency of the medication
- Storage Conditions: If the medicines are
stored properly in a cool and dry place, and kept unopened, the stability
of the medicines will be higher
- Package Type: The type of package will
also determine the stability and longevity of the medicines. In this
regard, an air-tight strip of tablets or capsules will be far superior to
an opened screw-cap container
- Formulation: The formulation is a
critical factor in the stability of the drug. Generally, liquid
formulations are less stable than solid formulations
Expired Medicines - To Take or Not to
what should be the 'bottom line' or 'take home' message? From the foregoing discussion, it is evident that expired
medicines are, by and large, not harmful
and retain their potency close to 90 percent of
the original potency at the time of manufacture. Therefore, under normal
circumstances, i.e. for mundane symptoms such as
headaches, muscle pain, sprains, stomach cramps, constipation and others,
expired medicines may be taken as none of these conditions are life-threatening.
However, for conditions on which your life is at stake, and for which 100
percent potency is desirable, it is best to go for new medicines and
discard the expired ones. After all, "It's better to be safe than sorry".
- Sandford-Smith J. Outdated Drugs May be Useful. Br Med J. 2003; 326(7379): 51.
- Simons FE, Gu X, Simons KJ. Outdated EpiPen and EpiPen Jr Autoinjectors: Past Their Prime? J Allergy Clin Immunol. 2000; 105(5): 1025-30.
- Cantrell L, Suchard JR, Wu A, Gerona RR. Stability of Active Ingredients in Long-expired Prescription Medications. Arch Intern Med. 2012; 172(21): 1685-7.
- Courtney B, Easton J, Inglesby TV, SooHoo C. Maximizing State and Local Medical Countermeasure Stockpile Investments Through the Shelf-Life Extension Program. Biosecur Bioterror. 2009; 7(1): 101-7.
- Lyon RC, Taylor JS, Porter DA, Prasanna HR, Hussain AS. Stability Profiles of Drug Products Extended Beyond Labeled Expiration Dates. J Pharm Sci. 2006; 95(7): 1549-60.
- Khan SR, Kona R, Faustino PJ, Gupta A, Taylor JS, Porter DA, Khan M. United States Food and Drug Administration and Department of Defense Shelf-Life Extension Program of Pharmaceutical Products: Progress and Promise. J Pharm Sci. 2014; 103(5): 1331-6.
- Frimpter GW, Timpanelli AE, Eisenmenger WJ, Stein HS, Ehrlich LI. Reversible "Fanconi syndrome" caused by degraded tetracycline. JAMA. 1963; 184(2): 111-3.