Beyond-use date: difference between revisions
Diff·revision 18 → 19·22:14, 11 Jun 2025
Difference between revision 18 and revision 19 of Beyond-use date. 9 lines changed; the page grew by 1,696 bytes.
| Revision 18 — 08:43, 26 May 2025 SyringeSybille (talk) add the shelf life after first puncture, attributed 13,672 bytes ±0 | Revision 19 — 22:14, 11 Jun 2025 StubSorterBot (talk) bot: add stub category 15,368 bytes +1,696 | ||
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| 95 | Reconstitution of a lyophilised product is the case most relevant to this wiki. Where the manufacturer has established a period for the reconstituted product, that period appears in the labelling and governs. Where no such period exists — the situation for essentially all peptides distributed for research use — no compendial default is directly applicable either, because the default tables in <797> govern preparations compounded under the chapter's conditions and not preparations made outside any such framework.{{r|usp797,ppbud}} | 95 | Reconstitution of a lyophilised product is the case most relevant to this wiki. Where the manufacturer has established a period for the reconstituted product, that period appears in the labelling and governs. Where no such period exists — the situation for essentially all peptides distributed for research use — no compendial default is directly applicable either, because the default tables in <797> govern preparations compounded under the chapter's conditions and not preparations made outside any such framework.{{r|usp797,ppbud}} |
| 96 | 96 | ||
| + | 97 | What is left is analogy. Community practice generally assigns about 28 days to a vial reconstituted with a preserved diluent and a much shorter period to one reconstituted with an unpreserved diluent, both refrigerated. The shape of that practice matches the compendial framework, and its numerical values are borrowed from it rather than derived. Its weakness is not the borrowing, which is reasonable, but the absence of any check: no sterility testing, no preservative-effectiveness testing and no assay of the reconstituted solution have been published for such preparations, so a beyond-use date so assigned is untested at both ends.{{r|ppbud}} | |
| + | 98 | ||
| + | 99 | == Assignment in the absence of data == | |
| + | 100 | Where a preparation-specific stability study is unavailable — the usual case — the compendial approach is to apply a conservative default and to shorten it where any consideration suggests it should be shorter. The considerations enumerated in <795> and <1191> include the nature of the active substance and its degradation mechanism, the container and its potential for sorption or permeation, the storage condition, the expected duration of use, and the presence of water.{{r|usp795,usp1191}} | |
| + | 101 | ||
| + | 102 | Date arithmetic is simple and worth stating explicitly, because errors in it are common and consequential. | |
| + | 103 | ||
| + | 104 | A lyophilised vial is reconstituted on 12 March and stored refrigerated. A 28-day period gives a beyond-use date of 9 April: the count runs from the day of preparation, and the beyond-use date is the last day on which the preparation may be used, not the first on which it may not — a convention on which sources differ, so that a stated date without a stated convention is ambiguous by a day. | |
| + | 105 | ||
| 97 | == References == | 106 | == References == |
| 98 | {{reflist}} | 107 | {{reflist}} |