USP General Chapter 71: difference between revisions
Diff·revision 8 → 9·09:47, 6 Feb 2025
Difference between revision 8 and revision 9 of USP General Chapter 71. 6 lines changed; the page grew by 681 bytes.
| Revision 8 — 09:29, 21 Jan 2025 StyleSheetSybil (talk) correct the water-content figure — the source reports it on a dry basis 2,254 bytes ±0 | Revision 9 — 09:47, 6 Feb 2025 GlossaryGleb (talk) convert a hard-coded date to the house format 2,935 bytes +681 | ||
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| 5 | | Methods = Membrane filtration; direct inoculation | 5 | | Methods = Membrane filtration; direct inoculation |
| 6 | }} | 6 | }} |
| + | 7 | {{hatnote|For the test and its statistical limits, see [[Sterility testing]].}} | |
| 7 | 8 | ||
| 8 | '''USP General Chapter 71''', titled ''Sterility Tests'', prescribes the media, incubation conditions, sample quantities and method-suitability procedures for demonstrating that a sample yields no microbial growth. It is a mandatory chapter where a monograph or regulatory requirement invokes it.{{r|usp71}} | 9 | '''USP General Chapter 71''', titled ''Sterility Tests'', prescribes the media, incubation conditions, sample quantities and method-suitability procedures for demonstrating that a sample yields no microbial growth. It is a mandatory chapter where a monograph or regulatory requirement invokes it.{{r|usp71}} |
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| 19 | Method suitability, formerly called the bacteriostasis and fungistasis test, requires demonstrating that the sample does not inhibit growth of the challenge organisms under the conditions used. Where the sample is inhibitory, the method must be modified — by filtration and washing, by neutralisation, or by dilution — until recovery is demonstrated.{{r|usp71}} | 20 | Method suitability, formerly called the bacteriostasis and fungistasis test, requires demonstrating that the sample does not inhibit growth of the challenge organisms under the conditions used. Where the sample is inhibitory, the method must be modified — by filtration and washing, by neutralisation, or by dilution — until recovery is demonstrated.{{r|usp71}} |
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| + | 22 | == Membrane filtration and its limits == | |
| + | 23 | Membrane filtration is preferred where applicable because it separates the sample from the growth medium: the organisms are retained on a 0.45 μm membrane, the sample and any inhibitory component pass through, and the washed membrane is incubated.{{r|usp71}} | |
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| + | 25 | The pore size is a compendial convention rather than an absolute cut-off. Organisms smaller than the nominal rating exist, and filtration is a retention process rather than a sieve, so retention is probabilistic. This is one of several reasons the chapter is framed as a test rather than as proof. | |
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| 21 | == References == | 27 | == References == |