How are eye drop expiration dates set?

Eye drop expiration dates come from stability testing. Under the FDA’s drug manufacturing rules in 21 CFR 211.137, a drug’s expiration date must be determined by appropriate stability testing, described in 21 CFR 211.166, so the product meets its standards at the time of use. The date also assumes the storage conditions on the label, which is why storage matters.

What the federal rule says

The rules for manufacturing finished drugs in the United States are in Title 21 of the Code of Federal Regulations, Part 211. Section 211.137 covers expiration dating. As published on govinfo.gov, it says a drug product should bear an expiration date determined by appropriate stability testing, so that it meets applicable standards of identity, strength, quality and purity at the time of use.

Two details in that section matter for anyone holding a bottle. First, the date is tied to the product meeting its standards when you use it, not just when it leaves the factory. Second, section 211.137 says expiration dates must be related to the storage conditions stated on the labeling. The date assumes the product has been kept the way the label says.

How stability testing works

Section 211.166 describes the stability testing program that sets the date. According to the regulation, a manufacturer needs a written program that includes:

• Sample sizes and test intervals based on statistical criteria for each attribute being measured.
• Specified storage conditions for the samples being tested.
• Test methods that are reliable, meaningful and specific.
• Testing of the drug in the same container-closure system it’s sold in.

In plain terms, the product is stored under defined conditions and checked at intervals to see how long it keeps meeting its specifications in its actual bottle. The expiration date reflects those results.

Why the container is part of the test

The requirement to test in the marketed container-closure system is easy to skim past, but it explains a lot. The bottle, its tip and its cap are part of what keeps the product stable. A drug that holds up well in one kind of container might not in another, so the date on your bottle reflects that specific package. It’s also one reason not to pour drops into a different container for travel or to refill a bottle. Once the product leaves the package it was tested in, the date no longer describes it. Putting the cap back on after each use keeps the bottle closed the way it’s sold.

A note on over-the-counter products

Section 211.137 includes a narrow provision for some over-the-counter drugs: its expiration dating requirements aren’t enforced for OTC products whose labeling has no dosage limitations and that are stable for at least three years, supported by stability data. That provision doesn’t mean an OTC product lacks a date. Many, including Quell, carry one. Check your own carton and bottle.

Where to find the date on your bottle

Expiration dates are usually printed on the carton and on the bottle label, often near the lot number. The format varies by manufacturer. Our guide on where to find the expiration date on eye drops walks through how to read it and what to do if it’s hard to find.

If a bottle arrives from us with a date that has already passed, contact us through the contact page or at 615.465.6041, M–F 9AM–5PM CST, and don’t use that bottle in the meantime.

Why storage matters for the date

Because the date is linked to the storage conditions on the label, keeping the bottle in range is part of what makes the date meaningful. Quell’s storage line reads: Store between 15° to 30°C (59° to 86°F). A bottle left on a hot dashboard in July or in a freezing car in January has been kept outside the conditions the date assumes.

• Keep the bottle in a drawer or cabinet at room temperature.
• Avoid sunny windowsills, bathrooms that get steamy and hot, and cars.
• Before using a bottle that has been somewhere hot or cold, look at it. The label’s “Do not use” line reads: If this product changes color.
• Know what normal looks like: The eye drops have a naturally milky-brown appearance. This is normal and does not indicate a problem with the product.

Expiration date vs. after opening

The expiration date applies to the product as packaged. Quell’s label doesn’t set a separate discard period after opening, such as a number of days. That’s a different question from expiration, and our guide on how long eye drops last after opening covers it. Whatever the dates say, handle the bottle as the label directs: Do not touch tip of bottle to any surface to avoid contamination.

What to do with an expired bottle

Once the date has passed, the stability testing no longer supports the product meeting its standards. Don’t use it. Throw it away according to local guidance for medicines, and start a new bottle. If you’re unsure, a pharmacist can help. The full Quell label is on our Drug Facts page.