Medidental

Multi-dose vial vs single-dose vial: what's the difference on the label?

A multi-dose vial contains more than one dose of sterile medication; a single-dose vial is designed for a single patient as a single injection. FDA and USP define both by intended use and antimicrobial effectiveness testing — not by preservative alone.

Multi-dose vial vs single-dose vial: what's the difference on the label?
Term Antimicrobial effectiveness testing Label statement Volume note
Single-dose "Not required to meet the antimicrobial effectiveness testing requirements." "When space permits, a single-dose container is labeled as such and should include on the label appropriate discard statements." USP <659>: "in no case is more than sufficient to permit the withdrawal and administration of 1 L."
Multiple-dose "Has met antimicrobial effectiveness testing requirements, or is excluded from such testing requirements by FDA regulation." "Multiple-dose containers do not normally have a discard statement"; 28-day beyond-use date for an opened/entered container unless the manufacturer specifies otherwise. FDA/USP Definitions: "generally expected to contain 30 mL or less." USP Injection Packaging: "Unless otherwise specified in the individual monograph, a Multiple-dose container contains a volume of injection sufficient to permit the withdrawal of NMT 30 mL."
Single-patient-use — "Should include on the label appropriate discard statements." —

What is a single-dose vial?

FDA's 2018 guidance defines a single-dose container as "a container of a sterile medication for parenteral administration (injection or infusion) that is not required to meet the antimicrobial effectiveness testing requirements." Examples: vials, ampules, prefilled syringes. That is guidance, not a rule — FDA states that "should" in an agency guidance "means that something is suggested or recommended, but not required."

One footnote answers the most common confusion: "Use of the term 'single-dose' container does not imply the entire contents of the container constitute a single dose." A single-dose vial may hold more drug than one dose, or multiple vials may be needed for one dose. USP <659> defines the same class as a container–closure system, a wording difference from FDA, and allows up to 1 L. Labeling "should typically include the statement 'Discard unused portion,'" and for products with a USP monograph the term "single-dose" is required on the container label when space permits (FD&C Act 502(g)).

What is a multiple-dose vial?

The antimicrobial requirement is the definition. A preservative is how many products meet it, which is why FDA's footnote 14 says the preservative is not the definition. CDC puts it in one word, across its two vial FAQs: multi-dose vials "typically contain an antimicrobial preservative," and single-dose vials "typically lack an antimicrobial preservative" — a labelling-correlated tendency, not the test.

On volume, the two USP sentences differ. USP <659> Definitions: multiple-dose containers are "generally expected to contain 30 mL or less." Its Injection Packaging section is a limit subject to override: "Unless otherwise specified in the individual monograph, a Multiple-dose container contains a volume of injection sufficient to permit the withdrawal of NMT 30 mL." FDA's guidance carried only the soft wording. The beyond-use date for an opened or entered multiple-dose container is 28 days "unless otherwise specified by the manufacturer on the label." Vaccines are carved out: unless labeled otherwise, "vaccines supplied in multiple-dose vials may be used up to the date of expiry of the product" (FDA footnote 18).

What is a single-patient-use container?

FDA retired the term "single-use" and created "single-patient-use" in its place. Examples: patient-controlled analgesia cartridges and certain pens for injection. The reason given: "the term 'single-use' was also inappropriately used as if it were interchangeable with the term 'single-dose'."

The 28-day beyond-use date has no single published derivation

Three publishers attribute it three different ways, and none derives it. FDA's 2018 guidance footnotes the 28-day figure to a Joint Commission standards FAQ. CDC attributes it to USP General Chapter <797>: "If a multi-dose has been opened or accessed (e.g., needle-punctured) the vial should be dated and discarded within 28 days unless the manufacturer specifies a different (shorter or longer) date for that opened vial." USP <659> simply asserts the figure in its own definition. No retrieved source derives the number.

CDC does draw the expiration-date distinction: "The manufacturer's expiration date refers to the date after which an unopened multi-dose vial should not be used. The beyond-use-date refers to the date after which an opened multi-dose vial should not be used. The beyond-use-date should never exceed the manufacturer's original expiration date." CDC adds: "The preservative has no effect on viruses and does not protect against contamination when healthcare personnel fail to follow safe injection practices."

One drug, both container types

Hospira's lidocaine label shows the difference on a single product. Lidocaine HCl 0.5% (250 mg per 50 mL) is listed as both "50 mL single-dose teartop vials" and "50 mL multiple-dose fliptop vials" — same drug, same strength, same fill volume. The differences are the preservative and the closure: "Multiple-dose vials contain 0.1% of methylparaben added as an antiseptic preservative," while the label states "Single-dose products are preservative-free." The single-dose label carries "For single-dose vials and ampuls: Discard unused portion."

The multiple-dose lidocaine label carries no 28-day statement at all, matching FDA's "Multiple-dose containers do not normally have a discard statement." Three of Hospira's five multiple-dose lidocaine presentations are 50 mL, which exceeds both USP's "NMT 30 mL" and FDA's "generally expected to contain 30 mL or less" — and neither the label nor the guidance explains the gap. Hospira's bacteriostatic water label shows the same pattern: two presentations with different preservative concentrations (0.9% and 1.1% benzyl alcohol), and no 28-day statement anywhere. Any 28-day figure for that product comes from the guidance default, not from the manufacturer.

We do not link a retail listing here. Every row above is a prescription drug product identified by an NDC, and the vials offered at retail are empty glass vials carrying no manufacturer catalogue number — they match nothing on this page.

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