Talk:Lyophilisation

Requested move. Propose moving this article to Lyophilization with a zed. The overwhelming majority of the primary literature cited in the article is published in American journals and uses that spelling, and the compendial chapters that govern the topic are USP chapters. Search volume also favours the zed spelling by a wide margin. — — MoveRequestMio (talk) 09:40, 11 February 2025 (UTC)

Oppose. Project:Manual of style settled this: the wiki uses British spelling throughout, and it does so consistently — we write lyophilised, characterised, sulfur (which is IUPAC, not American), and colour. Moving one article to American orthography would make us internally inconsistent in exchange for nothing. The redirect from the zed spelling already exists and already works. — — StyleSheetSybil (talk) 11:22, 11 February 2025 (UTC)

Oppose per Sybil. Note also that the argument from source spelling proves too much: by that logic Karl Fischer titration would move to a German title. What matters is house style, and house style is settled. — — HyphenHarriet (talk) 08:05, 12 February 2025 (UTC)

The German comparison is not quite fair — that is a proper noun, not orthography. But I take the internal-consistency point, which is the strongest argument here. — — MoveRequestMio (talk) 13:47, 12 February 2025 (UTC)

Weak support for a narrower change: keep the title but add a note in the lead that the zed spelling is the dominant form in the literature, so a reader searching the sources is not confused. That gets the practical benefit without the style churn. — — LyophilLena (talk) 10:14, 13 February 2025 (UTC)

Closing as not moved. Consensus is clear against, on house-style grounds. Lena's suggestion is uncontroversial and does not need a move discussion — someone should just add it. — — Ref_Desk_Ron (talk) 09:33, 18 February 2025 (UTC)

§Freezing defines Tg′ and §Primary drying defines Tc, and the article says Tc is conventionally 1–3 °C above Tg′ — but in two other places it slides between them as if they were one quantity. They are measured differently: Tg′ by differential scanning calorimetry, Tc by freeze-drying microscopy. The gap between them is also formulation-dependent and has been reported as larger than 3 °C for some systems. — — StabilityStig (talk) 11:07, 19 September 2025 (UTC)

Agreed on the measurement distinction. On the size of the gap, I have seen figures up to 5 °C quoted for amorphous small-molecule systems but I cannot put my hand on the paper. If we cannot source a range we should say only that Tc lies above Tg′ and that the difference is formulation-specific. — — LyophilLena (talk) 15:31, 19 September 2025 (UTC)

That is the right conservative wording. The 1–3 °C figure is defensible as a typical value for the systems in Tang and Pikal, so it can stay if it is attributed to that source rather than stated flatly. — — AnalyticalAnnie (talk) 09:55, 21 September 2025 (UTC)

Attributed it. Leaving the thread open because the two remaining loose uses in §Formulation still need tidying and I have run out of evening. — — StabilityStig (talk) 08:20, 22 September 2025 (UTC)

§Secondary drying says the moisture-degradation relationship is not monotonic and that over-dried preparations have shown reduced stability. Both cited sources are protein reviews. The article is read mostly by people interested in short synthetic peptides, where I am not aware of any demonstration of an over-drying penalty. The claim may be true and simply untested for peptides, but as written it reads as though it applies to the subject of this wiki. — — CitationChaser (talk) 10:26, 14 January 2026 (UTC)

That is a fair distinction and it applies to a lot of what we import from the protein-formulation literature. Suggest the sentence is scoped explicitly to proteins, with a clause saying the equivalent question for short synthetic peptides appears not to have been addressed in the published literature. Saying so is more useful than either asserting or omitting it. — — Peptide_Pete (talk) 13:09, 14 January 2026 (UTC)

Support scoping it. The mechanism argued in the protein literature is conformational — a hydration monolayer maintaining tertiary structure — and a twelve-residue peptide with no tertiary structure to maintain has no obvious reason to behave the same way. Which is itself an inference, so it should not go in the article. — — KarlFischerKit (talk) 08:41, 16 January 2026 (UTC)

Agreed on all counts including that the mechanism argument stays on this page. I will scope the sentence this week. — — CitationChaser (talk) 09:58, 16 January 2026 (UTC)

The 0.16 g per hour figure is per vial, and the article says so, but it then converts straight to 12.5 hours for a 2 mL fill without noting that batch behaviour is what a reader would care about. A reader could come away thinking a dryer holding 3,000 vials removes 0.16 g per hour. — — PlainNumbersPip (talk) 12:15, 2 March 2026 (UTC)

The per-vial duration is the right thing to compute, because vials dry in parallel and the cycle length is set by the slowest vial, not by total mass. But you are right that the text does not say so. I have added a clause. Total batch mass flow matters only for the condenser and duct limits, which are in §Scale-up. — — ColdChainCleo (talk) 14:52, 2 March 2026 (UTC)

Checked the arithmetic independently: 0.126 W divided by 2.83 MJ per kg is 4.45 × 10⁻⁸ kg/s, which is 0.160 g/h. 2.0 g at that rate is 12.5 h. Consistent. — — UnitAuditUwe (talk) 09:11, 3 March 2026 (UTC)

Clause added, arithmetic independently checked, nothing outstanding. Closing. ✓ Done — — Ref_Desk_Ron (talk) 10:40, 5 March 2026 (UTC)

§Why lyophilised material tolerates ambient shipping is good material but it duplicates ground covered at Cold chain and Temperature excursion, and it is the only section in a process-chemistry article that talks about parcels. Would it be better as two sentences plus a main-article pointer? — — ScopeSeverin (talk) 15:30, 21 April 2026 (UTC)

I would keep it. The physical explanation for why the practice is defensible is a solid-state argument, and this is the article where the solid state is explained. Cold chain covers the logistics; it should not have to re-derive glass-transition behaviour. — — FreightFenna (talk) 08:47, 22 April 2026 (UTC)

That is a reasonable division of labour. I will leave it and instead check that the two articles are not contradicting each other on the glass-transition figures. — — ScopeSeverin (talk) 11:05, 24 April 2026 (UTC)