Pharmacology · Formulation chemistry

About the Formulation chemistry category

Pharmacology › Formulation chemistry bacteriostatic water sterile water cloudy or discoloured solution

Pinned Wiki

hana.satoTL4 Moderator17 Dec 2024#1

Community wiki post. Any member at trust level 3 or above can edit this post; every edit is recorded. Last edited by hana.sato on 21 Jun 2025.

9 Jan 2025 — hana.sato: Corrected an arithmetic slip in the second example.
11 Mar 2025 — mira.patel: Plain-language pass on the opening paragraph.
21 Jun 2025 — hana.sato: Restructured into sections so the outline is navigable.

Editors: hana.sato, mira.patel, hana.sato

Staff post. Actions described here are recorded in the public moderation log and may be challenged in Meta.

Buffers, pH, isotonicity, preservatives, lyophilisation and excipient function.

This post is a community wiki: any member at trust level 3 or above can edit it, and every edit is recorded with its author and a note. If the scope described here has drifted from what actually gets posted, edit it rather than starting a topic about it.

What belongs here

Questions specific to formulation chemistry, with the units and the context stated.
Reports and datasets, with the collection method stated.
Disagreement about the substance, conducted in public.

What belongs elsewhere

Anything urgent belongs in Safety, immediately, and not here.
Anything about how this site works belongs in Meta.
Requests for a maintained page belong in Wiki requests.

Before posting, it is worth checking the documentation commons and this category's tag pages. A great deal of what gets asked here has a maintained answer with a review date on it, which is more reliable than a two-year-old reply.

0 likes 19mo

bench_notesTL4 Moderator2 Jan 2025#2

Staff post. Actions described here are recorded in the public moderation log and may be challenged in Meta.

Moderation notes for this category, so that nothing about how it is run is a surprise.

Topics get moved into and out of here regularly. A move is not a judgement — the category tree is not obvious from outside and putting a question in the wrong place is expected. When I move something I say so in the topic and the action appears in the public log with the guideline cited.

The two guidelines that come up most often in this category are R2, on supplying a source when asked, and R7, on category placement. Neither is used punitively.

3 likes 19mo

ka.batistaTL2 Moderator13 Jan 2025#3

As a member rather than staff: the most useful thing I did when I started reading this category was to work through the tag pages rather than the topic list. The topic list shows you what is recent. The tags show you what is settled.

11 likes 18mo

vial_tableTL2Member23 Jan 2025#4

Suggestion for the wiki post above: it would be worth linking the two or three most-referenced topics in this category directly, since new members reliably ask for exactly those. Happy to make the edit myself if nobody objects, with a revision note.

24 likes 18mo

ro.friskTL2 Moderator2 Feb 2025#5

bench_notes, post #2: Moderation notes for this category, so that nothing about how it is run is a surprise. Topics get moved into and out of here regularly. A move is not a judgement — the category tree is not obvious from outside and putting a question in the wrong place is expected. When I move something I say so in the topic and the action appears in the… Go to post

Fill volume and headspace: the amount of solution in a vial and the air above it affect how much the solution is exposed to oxygen during storage. Less headspace means less oxygen exposure.

1 like in reply to #2 18mo

This topic was referenced in

Excipient function in a licensed injectablePharmacology › Formulation chemistry · 7 replies

Suggested topics

Topic	Participants	Replies	Views	Activity
Follow-up: Lyophilisation and why the cake looks the way it does Pharmacology › Formulation chemistry bacteriostatic water cloudy or discoloured solution sterile water Solved Lyophilisation and why the cake looks the way it does Writing it up because I had to work it out twice and would rather nobody else did. I would like to understand what this number means before I repeat it…	+10	14	11k	3mo
Excipient function in a licensed injectable — the long version Pharmacology › Formulation chemistry sterile water storage bacteriostatic water Posting this under the heading it deserves: Excipient function in a licensed injectable — the long version Everything below is what sits behind that. Working through the identity arithmetic and I would like…		2	100	15mo
Isotonicity and what happens when you get it wrong Pharmacology › Formulation chemistry sterile water counter-ion content storage On the subject in the title: Isotonicity and what happens when you get it wrong Working notes rather than a conclusion. Posting the method first, because I know what the first three replies will otherwise be.…	+27	31	11k	18mo
Coming back to: Adsorption to container surfaces and to plastics Pharmacology › Formulation chemistry bacteriostatic water counter-ion content storage sterile water Adsorption to container surfaces and to plastics — setting out what I have, and where I think it stops being reliable. Posting the method first, because I know what the first three replies will otherwise be.…		2	459	17mo
Preservatives: function, testing, and limits Pharmacology › Formulation chemistry counter-ion content storage bacteriostatic water sterile water Preservatives: function, testing, and limits — setting out what I have, and where I think it stops being reliable. Working through the identity arithmetic and I would like it checked. tirzepatide has a…	+23	27	3.7k	16mo

Related topics — sharing the tags bacteriostatic water, sterile water, cloudy or discoloured solution

Topic	Participants	Replies	Views	Activity
Follow-up: A parcel that arrived warm: a decision process, not a verdict Practice › Storage & stability temperature excursion cloudy or discoloured solution beyond-use date Posting this under the heading it deserves: A parcel that arrived warm: a decision process, not a verdict Everything below is what sits behind that. A question about technique rather than about dose. I have…	+49	59	1.2k	2mo
Converting between mg/mL and units per dose, both directions Practice › Reconstitution concentration maths dead volume bacteriostatic water Solved Posting this under the heading it deserves: Converting between mg/mL and units per dose, both directions Everything below is what sits behind that. Practical question with the units stated, because I have…	+106	142	9.5k	19mo
Follow-up: The decimal-point error, and the habit that catches it Practice › Reconstitution concentration maths bacteriostatic water dead volume reconstitution Closed On the subject in the title: The decimal-point error, and the habit that catches it Working notes rather than a conclusion. I have read the maintained page on this and I still have a gap, so I am asking…	+118	131	50k	7mo
Lyophilisation and why the cake looks the way it does Pharmacology › Formulation chemistry sterile water bacteriostatic water storage cloudy or discoloured solution Posting this under the heading it deserves: Lyophilisation and why the cake looks the way it does Everything below is what sits behind that. I would like to understand what this number means before I repeat…	+33	37	60k	6mo
Revisiting: Power cut for eleven hours: how I assessed it afterwards Practice › Storage & stability storage freeze-thaw beyond-use date cloudy or discoloured solution Revisiting: Power cut for eleven hours: how I assessed it afterwards — setting out what I have, and where I think it stops being reliable. A question about technique rather than about dose. I have been doing…		4	195	9mo

Sponsored Sigma-Aldrich — certified reference materialsReference standards, analytical reagents and certified materials for method calibration. If you are validating a method, this is where the standard comes from.Reference standards →