Multidose Vial Discard Ledger

Audit remaining vial doses against a caller-provided post-opening discard interval; other storage requirements are not inferred.

Description

Partition each vial’s remaining doses by a supplied post-opening interval and total the doses still inside that time window.

A multidose vial can retain unused doses after opening. An inventory ledger must track both those remaining doses and elapsed time since opening. Product-specific handling also involves storage, expiry, and contamination considerations; an opening-time check covers only one part of suitability.^[1]

This tool applies one caller-supplied discard interval to a set of distinct vial records. Day values are elapsed coordinates on the same time axis, so fractional days can represent hours. A vial reaches the discard boundary when its age equals the interval.

Multidose Vial Discard Ledger reports usable and discarded remaining doses in input order. Here usable means still inside the supplied opening-time window, not independently approved for administration.

When to audit an opening-time inventory ledger

Use the tool after selecting the applicable interval for a compatible group of vials. Record initial doses, used doses, and opening times consistently; different product intervals require separate calculations.

Identify remaining doses that have reached the supplied time boundary.
Total doses still within the chosen opening-time interval.

How to enter vial records and partition remaining doses

Enter nonempty distinct Vial ids and aligned Opened days, Initial doses, and Used doses lists.
Use nonnegative integer dose counts with used no greater than initial, and opening days no later than Evaluation day.
Enter positive Discard after days and nonnegative Evaluation day on the same day axis.
Run the ledger and pair each output entry with its vial ID; inspect Total usable doses.

remaining_i = initialDoses_i − usedDoses_i; age_i = evaluationDay − openedDays_i

If age is strictly less than discardAfterDays, remaining doses enter usableDoses. At equality or later, they enter discardedRemainingDoses. The other category receives zero.

json

{
  "input": {
    "vialIds": [
      "A",
      "B"
    ],
    "openedDays": [
      0,
      2
    ],
    "initialDoses": [
      10,
      10
    ],
    "usedDoses": [
      3,
      2
    ],
    "discardAfterDays": 3,
    "evaluationDay": 4
  },
  "output": {
    "usableDoses": [
      0,
      8
    ],
    "discardedRemainingDoses": [
      7,
      0
    ],
    "totalUsableDoses": 8
  }
}

The tool sums only usable entries. Empty/misaligned lists, duplicate IDs, excessive used counts, future opening days, and invalid numeric domains produce errors. An exhausted vial contributes zero to both dose totals.

Limitations and interpretation

The interval is supplied, not chosen from a vaccine label or a universal opened-vial rule.
No expiry date, temperature history, vial monitor, sterility, reconstitution rule, or product identity is checked.
The discarded output categorizes remaining doses at evaluation time; it does not confirm a physical discard or audit historical withdrawals.
All records use one interval. ID matching is exact, without automatic trimming or alias resolution.

Alternative or Complementary methods

Review temperature excursions separately and retain the product-specific handling instructions with the ledger. Other quality screens use distinct measurements and do not establish that remaining inventory is suitable.

References

WHO policy on the use of opened multi-dose vaccine vials (2014 Revision) — World Health Organization

Similar or alternative tools

Cold Chain Excursion Integral
Sum time outside supplied temperature bounds from interval records.
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Compare lot measurements with a supplied endotoxin concentration limit.