CEI-MS-05 — procedure

§4Procedure

The procedure below is written in the second person, which is the only place in the Institute's document set where that register is used. A procedure is an instruction and is written as one.

1. Calculate the endotoxin limit. For a parenteral other than intrathecal, the limit is 5.0 EU per kilogram of body mass per hour. For a 70 kg subject and a maximum hourly dose M in milligrams, the limit in EU per milligram is 350 ÷ M.
2. Determine the maximum valid dilution as the endotoxin limit multiplied by the sample concentration and divided by the labelled lysate sensitivity.
3. Reconstitute the sample in lysate reagent water. Confirm the pH falls within 6.0–8.0; adjust with pyrogen-free buffer if not.
4. Prepare a standard curve of not fewer than four concentrations spanning the labelled sensitivity, in duplicate.
5. Prepare the sample at a dilution not exceeding the maximum valid dilution, and a positive product control spiked at a concentration in the middle of the standard curve.
6. Incubate and acquire. Determine onset times or absorbance change as appropriate to the technique.
7. Assess interference from the positive product control recovery. Where recovery falls outside 50–200 %, the sample interferes and must be further diluted, treated, or analysed by an alternative technique.
8. Report endotoxin concentration in EU per milligram of peptide, the dilution used, the positive product control recovery, and the calculated limit for the stated intended dose.

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.

1. United States Pharmacopeial Convention. General Chapter ⟨85⟩ Bacterial Endotoxins Test. United States Pharmacopeia — National Formulary (USP–NF) 2024;USP 2024 Issue 1. 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.