Draft standard CEI-MS-12: Residual solvent determination by… — submissions
The 15 submissions received, published in full with declared interests and secretariat responses.
§2Submissions and responses
15 submissions were received. Each is published in full below with its declared interest, the secretariat response and the disposition. The Institute publishes submissions it did not accept in the same form as those it did.
Quantitative claims are reproduced without the method that produced them
Several figures in the draft are quoted from sources that determined them by different methods. A figure obtained by one determination and a figure obtained by another are not comparable, and the draft places them in the same sentence without distinguishing them.
The respondent, an analytical chemist, proposes that every quantitative claim carry the method that produced it at the point of use rather than in the reference.
The secretariat accepts this submission. Placing two figures side by side is an implicit claim that they are the same kind of quantity, and in the cases identified they were not.
Every quantitative claim now carries the determination that produced it at the point of use, and figures obtained by non-comparable methods are no longer presented in the same row or sentence.
The limitations section states what the method cannot do but not what a reader will wrongly conclude
The limitations section is accurate and abstract. The respondent states that the misreadings this standard should prevent are specific and predictable, and that naming them would be more use than a general statement of scope.
The respondent proposes that the limitations section list the specific inferences a conformant result does not support.
The secretariat accepts this submission. A limitation stated abstractly is a limitation a reader will not apply to the case in front of them.
The limitations section now lists the specific conclusions a conformant determination does not support, each stated as a sentence a reader could otherwise have written, and the list is placed before the references rather than in an annex.
Terms are used in senses that differ from established pharmacopoeial usage
The respondent, employed by a national competent authority and writing in a personal capacity, identifies three terms used in the draft in senses that differ from their established pharmacopoeial meanings.
The respondent proposes that established usage be followed or that the departure be stated explicitly at first use.
The secretariat accepts this submission. A term used in a private sense inside a document that will be read alongside compendial texts is a source of avoidable error.
The three terms now follow established pharmacopoeial usage, the glossary records the definition and its source, and where the Institute uses a term in a narrower sense the departure is stated at first use in the standard.
Nothing requires the report to state who performed the determination
The respondent states that certificates in circulation frequently reproduce results generated by a third party without identifying it, and that a reader cannot tell whether the releasing party performed the work.
The respondent proposes that the performing laboratory be a required field.
The secretariat accepts this submission. Attribution of a determination is a precondition of assessing it.
The report now requires the identity of the laboratory that performed the determination, its accreditation status where claimed, and a statement of whether the releasing party is the performing party, with the fields classified as critical.
A single method cannot support the conclusion the standard permits
The respondent states that species invisible to this determination will not appear in the result, and that a conclusion about the material as a whole requires an orthogonal method.
The respondent proposes that an orthogonal determination be mandatory.
The secretariat accepts this submission in part. An orthogonal determination is required where a conclusion about the material as a whole is to be drawn. It is not required where the standard is used to report the quantity it measures.
The standard now distinguishes a determination of the measured quantity, which stands alone, from a conclusion about the material, which requires a named orthogonal determination, and states that the second claim made on the strength of the first alone is not conformant.
The standard does not state that a determination on one unit says nothing about the batch
The respondent states that determinations under this standard are generally performed on a single unit and that certificates then travel with every unit of a batch, so that a single-unit result is routinely read as a batch result.
The respondent proposes that the standard require a sampling statement on the face of every determination.
The secretariat accepts this submission. The inference from unit to batch is the most consequential unstated assumption in supply documentation.
Every determination made under this standard now carries a sampling statement recording how many units were sampled, from what population and by what plan, and the standard states that a determination on a single unit supports no inference about any other unit.
A field classified as critical is not one a reading turns on
The respondent examines the fields classified as critical and states that two of them are administrative rather than interpretive, so that a certificate could be rendered uninterpretable by an omission that changes no reading.
The respondent proposes that a field be classified critical only where its absence changes what the figure means.
The secretariat accepts this submission in part. One field is reclassified as recommended on the test the respondent proposes. The second is retained as critical because its absence prevents the determination being attributed to a batch.
The classification test is now stated in the standard: a field is critical where its absence changes the meaning of a reported figure or prevents attribution to a batch. One field has been reclassified under that test and the reasoning recorded.
A determination does not record the version of the standard it was made under
The respondent states that the standard will be revised and that results reported under different versions will circulate together, indistinguishable from one another.
The respondent proposes that the standard identifier and version be carried on the face of every determination.
The secretariat accepts this submission. A conformance claim against an unspecified version is not a conformance claim.
Every determination reported under this standard now carries the standard identifier and version on its face, and a claim of conformance that does not identify the version is recorded by the Institute as not conformant.
References should carry a persistent identifier for every cited source
Several references in the draft carry a journal, a year and a volume but no persistent identifier. The respondent, who works in a library setting, states that retrieval of such a reference is materially slower and that identifiers should be supplied throughout.
The respondent asks in the alternative that where an identifier exists but is not carried, the omission be explained rather than left as a gap the reader must interpret.
The secretariat accepts the second limb of this submission and declines the first. Identifiers are supplied wherever the Institute holds one. Where the Institute does not hold an identifier it will not supply one, because a reconstructed identifier that resolves to the wrong record is a worse defect than an absent one.
Every reference without a persistent identifier now carries an explicit statement that the identifier is not held by the Institute, so that its absence is a recorded fact rather than an apparent oversight.
The standard should state a pass limit
The respondent states that a standard which reports a figure without a limit leaves the reader without a criterion, and that suppliers will set their own.
The respondent proposes a universal acceptance limit for the determination.
The secretariat does not accept this submission. An appropriate limit depends on the compound, the presentation and the intended route, none of which the standard fixes.
The standard states performance and reports the figure as determined. Setting a universal limit would attach a pass or fail to materials whose acceptable ranges genuinely differ, which would be a stronger claim than the Institute can support. The submission remains published in full and the point is recorded in the limitations.
Results are reported without an estimate of measurement uncertainty
The respondent, an analytical chemist, states that a figure reported to one decimal place implies an uncertainty the standard nowhere estimates, and that two determinations differing within the uncertainty will be read as a difference.
The respondent proposes that an uncertainty budget be required for every determination.
The secretariat accepts this submission in part. A repeatability figure and a stated reporting precision are required. A full uncertainty budget is not, because the standard is written to be usable by laboratories that do not maintain one and the requirement would exclude them without improving the reading.
Every determination now reports the repeatability observed in the run, the reporting precision, and a statement that two results differing by less than the stated repeatability are not distinguishable by this method.
Nothing requires a laboratory to demonstrate ongoing performance
The respondent states that suitability criteria assessed within a run demonstrate that the run worked and not that the laboratory performs consistently over time.
The respondent proposes participation in a proficiency scheme as a condition of conformance.
The secretariat accepts this submission in part. A trend requirement on system suitability data is added. Proficiency scheme participation is not made a condition of conformance, for the same reason competence requirements are not.
The standard now requires that system suitability results be trended across runs and that a determination report whether the trend was within the laboratory's stated limits, which places the demonstration inside the document the Institute can read.
Rounding conventions are not stated and change the reported result
The respondent states that the draft reports figures to varying precision and does not specify when rounding occurs in the calculation chain, which can move a result across an acceptance limit.
The respondent proposes that rounding occur only at the reporting step and that the convention be stated.
The secretariat accepts this submission. Intermediate rounding is a silent source of disagreement between laboratories analysing the same material.
The standard now requires that no rounding be applied before the reporting step, states the reporting precision for each quantity, and states the rounding convention used at that step.
The standard would be applied more consistently with a worked example
The respondent states that the requirement most often misapplied in practice is the one the draft states most briefly, and that a worked calculation would settle it.
The respondent proposes a worked example showing the same data treated correctly and incorrectly, with both results stated.
The secretariat accepts this submission. An example showing only the correct treatment does not show the reader what they are doing wrong.
A worked example is added showing the same primary data treated two ways, with both resulting figures stated and the difference between them quantified, so that the consequence of the misapplication is visible rather than described.
The standard should require documented operator competence
The respondent states that the determination described requires judgement, particularly at the integration step, and that a competence requirement would improve consistency more than any change to the criteria.
The respondent proposes that conformance be conditional on documented operator training.
The secretariat does not accept this submission. Operator competence is a quality-system matter governed by accreditation requirements the Institute does not administer and cannot verify.
The standard states performance and remains silent on competence. Where judgement affects the result, as at the integration step, the standard requires the judgement to be recorded rather than the operator to be qualified, which is the part the Institute can check from a report. The submission remains published in full.
References cited on this page
References are numbered in order of first citation in this document. Each superscript in the text links to its entry below.
- International Organization for Standardization. ISO/IEC 17025:2017 General Requirements for the Competence of Testing and Calibration Laboratories. ISO/IEC Standard 2017;3rd edition. identifier not held by the Institute
Identifiers are reproduced only where the Institute holds them. Where a digital object identifier or PubMed identifier is not shown, the Institute has recorded the journal and year and has not constructed an identifier.