The reasons drugs get recalled, counted from FDA's own records

Of the 18,076 drug recall records in FDA's enforcement database, 5,343 carry the same five words in the reason field: "Lack of Assurance of Sterility." That is close to three in every 10 drug products recalled since June 2012, according to a GxRadar count of the openFDA drug enforcement feed¹ as last updated on Oct. 28, 2026. All but 10 of those 5,343 records were classed as Class II.

Sterility tops the list, but it has company. The openFDA field reference² describes the reason field only as information on how a product is defective and violates the law. In practice FDA staff fill it with a fairly stable set of stock phrases, and because the same wording recurs, the reasons can be grouped and counted.

Counted that way, a small number of failure types account for most drug recalls, and they split along product lines. Sterility problems and stray particles cluster in injectables and eye drops. Dissolution and potency failures cluster in tablets and capsules. Manufacturing lapses and impurities cut across both. The split matters because a recall notice describes one lot from one maker; it says much less about the molecule than a headline might suggest.

How the count works

Each record in the feed is one product, so one recall event can produce dozens or hundreds of records. When a compounding pharmacy or outsourcing facility pulls its whole sterile line after an inspection, the event can add hundreds of entries at once. GxRadar counted distinct recall events next to product records to correct for that. A single record can also cite more than one reason, so the rows below overlap and do not sum to the total.

Year-by-year totals and recent records are on GxRadar's recall tracker, built from the same feed.

Sterility and particles in injectables

"Lack of Assurance of Sterility" means the maker cannot show that a product meant to be sterile was made under conditions that guarantee it. It does not by itself mean contamination was found. The usual products are injectables, IV fluids and eye drops, where a lapse would give microbes a direct route into the body.

The gap between 5,343 records and 445 events is the compounding effect at work. The class split points the same way. Class II, in FDA's definitions⁴, covers products that may cause temporary or medically reversible harm, or where the chance of serious harm is remote; a missing sterility assurance usually lands there unless contamination is confirmed.

Particulate matter is the close cousin: visible or sub-visible bits of glass, fiber or undissolved drug in an injectable. In the feed it turns up most often in sodium chloride injection, propofol and ketorolac. GxRadar's piece on why sterile injectables dominate shortage lists covers the same manufacturing fragility from the supply side.

Manufacturing lapses filed as CGMP deviations

Current good manufacturing practice, the rules set out in 21 CFR Part 211⁶, sets minimum standards for how finished drugs are made, tested and documented. "CGMP Deviations" is the broadest reason in the data and has the most distinct events, 654. It covers failures that call quality into question without a single failed test: inadequate cleaning, unvalidated processes, missing records, data integrity problems.

Many of these follow an inspection. When investigators leave a list of observations and the company or FDA concludes product already shipped may be affected, a recall can follow; the sequence is laid out in GxRadar's explainer on inspections, Form 483s and warning letters, and the rules themselves in CGMP explained.

CGMP was also the label FDA used for many nitrosamine recalls, which is why losartan, valsartan and metformin sit high in this category.

Impurities, and the nitrosamine years

Every drug has limits on impurities and degradation products. A recall for failed impurities or degradation specifications means a batch tested above one of those limits, at release or during stability testing over its shelf life.

Nitrosamines are the best-known case of the past decade. In summer 2018 FDA reported that some generic angiotensin receptor blockers (valsartan, then losartan and irbesartan) contained NDMA, NDEA or NMBA. On its ARB recall page⁷, FDA calls NDMA and NDEA probable human carcinogens and says the impurities can form when specific chemicals and reaction conditions are present in making the active ingredient, or can come from reused materials such as solvents. It also says not every product, and not every lot from an affected maker, was recalled.

Ranitidine went further than the others. FDA's April 2020 announcement⁸ said the impurity in some ranitidine products increases over time and when stored at higher than room temperatures, so a lot that passed at release might not stay within limits. That is why the agency asked for the whole molecule to come off the market rather than specific lots. For metformin, FDA's running updates⁹ tracked recalls of extended-release products only.

FDA's nitrosamine guidance, revised in September 2024¹⁰, sets acceptable intake limits so that the added cancer risk stays at about one additional case in 100,000 people, based on a conservative assumption of daily exposure over a lifetime of 70 years. The longer history, including newer limits for nitrosamines that form from the drug molecule itself, is in GxRadar's article on nitrosamine impurities.

Pills that dissolve wrong or test weak

A dissolution test measures how much drug comes out of a tablet or capsule in a lab vessel over a set time, as a stand-in for how it will release in the body. A failed result means a batch released drug faster or slower than its specification allows.

Release rate is the whole point of a modified-release product, so those dominate this category. Diltiazem, divalproex and metoprolol succinate appear repeatedly, along with doxycycline hyclate and potassium chloride. There are 346 such records across 266 events, a ratio close to one, which suggests these are usually single-product recalls.

Potency problems are counted in two directions. Subpotent means a batch tested below its labeled strength, superpotent means above, and the first is far more common: 693 records against 199. Subpotency can surface at release or later in stability testing if a product loses strength faster than expected. Levothyroxine has more subpotency records than any other molecule in the feed, 74 tagged with its generic name, followed by a combination of amlodipine and atorvastatin.

Labels, mix-ups and recall classes

Labeling reasons run from minor to serious. A missing or wrong expiration date is usually Class III, which FDA defines⁴ as a situation not likely to cause adverse health consequences. A label mix-up, where the wrong drug or strength is in the package, can be Class I, the tier reserved for a reasonable probability of serious harm or death, because a patient may take the wrong medicine.

Mix-ups are rare as events. Records citing a label mix-up number 442, but they come from only 13 events, so a few large incidents produced most of them. The classification itself is FDA's call: the agency's Enforcement Report definitions³ and the recall rules in 21 CFR Part 7⁵ describe how it weighs health hazard, and GxRadar's guide to how recalls work walks through the process from a company's first notice to termination.

Every record carries a lot number and the name of the recalling firm, which is how a pharmacist can tell whether a dispensed bottle is part of a recall. GxRadar's guide to reading an FDA recall notice shows where those fields sit, and the openFDA feed adds new records each week.