Liraglutide — analytical characterisation
Chromatographic conditions, identity, related substances, presentation, reconstitution and in-use stability.
§6Analytical characterisation
§6.1Chromatographic conditions
- Column
- C18, 4.6 × 150 mm, 3.5 µm
- Mobile phase and gradient
- A: phosphate buffer pH 7.4 or 0.1 % trifluoroacetic acid; B: acetonitrile. Gradient 30–55 % B over 25 min
- Detection
- UV 214 nm; 280 nm confirmatory
- Retention
- Elutes earlier than semaglutide under matched conditions because of the shorter, mono-acid lipid
§6.2Identity by mass spectrometry
[M+3H]³⁺ at m/z ≈ 1251.4; deconvoluted average mass 3751.2 ± 2 Da.[3]
§6.3Related substances and degradation
Table 7. Related substances recorded for Liraglutide, with the process or storage route that generates each and its analytical signature.
| Related substance | Origin | Analytical signature |
|---|---|---|
| Non-acylated GLP-1(7-37) Arg34 backbone | Failed palmitoylation | −375 Da approximately; elutes markedly earlier |
| Bis-acylated species | Over-conjugation at a second amine | +375 Da approximately; elutes later |
| Deamidated forms | Storage | +1 Da |
| Palmitic acid | Free fatty acid from hydrolysis | Not UV-active at 214 nm in useful proportion; requires a separate method |
Degradation routes
- Fibrillation is a well-documented risk for liraglutide at low pH or on agitation and is not detected by reverse-phase purity
- Deamidation on prolonged aqueous storage
- Hydrolysis of the γ-glutamate linkage under extremes of pH
§7Presentation, reconstitution and storage
§7.1Presentation and reconstitution
- Presentation
- Aqueous multi-dose pen (approved products); lyophilised powder in research supply
- Reconstitution
- A 5 mg vial with 1.0 mL gives 5 mg/mL; a 0.6 mg starting dose is then 0.12 mL, that is 12 units on a U-100 syringe.
- Storage, lyophilised
- 2–8 °C; −20 °C for extended storage of research material
- Storage, reconstituted
- 2–8 °C, do not freeze
- In-use period
- Approved pens: 30 days at up to 30 °C or 2–8 °C after first use. No in-use claim is published by the Institute for reconstituted research material.
Liraglutide self-associates in solution; this is a designed property, not a defect, but it means dynamic light scattering and size-exclusion results must be interpreted against a reference standard rather than against a generic aggregation limit.
§7.2In-use stability
Applicable standards: CEI-MS-01 · CEI-MS-02 · CEI-MS-03 · CEI-MS-04 · CEI-MS-05 · CEI-MS-06. The full series is at methodological standards.
Working calculators: reconstitution and insulin-unit conversion · purity against peptide content · certificate minimum-data checker.
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.
- United States Pharmacopeial Convention. General Chapter ⟨1225⟩ Validation of Compendial Procedures. United States Pharmacopeia — National Formulary (USP–NF) 2024;USP 2024 Issue 1. identifier not held by the Institute
- International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. ICH Q2(R2) Validation of Analytical Procedures. ICH Harmonised Guideline 2023;Step 4 version, 1 November 2023. identifier not held by the Institute
- International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. ICH Q6B Specifications: Test Procedures and Acceptance Criteria for Biotechnological/Biological Products. ICH Harmonised Tripartite Guideline 1999;Step 4 version. identifier not held by the Institute
- International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. ICH Q1A(R2) Stability Testing of New Drug Substances and Products. ICH Harmonised Tripartite Guideline 2003;Step 4 version. identifier not held by the Institute
- Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharmaceutical Research 2010;27(4):544–575. doi:10.1007/s11095-009-0045-6 · PMID 20143256
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.