GHRP-6 — 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: 0.1 % trifluoroacetic acid in water; B: acetonitrile. Gradient 12–40 % B over 20 min
- Detection
- UV 214 nm; 280 nm very strong (two Trp)
- Retention
- Late for a hexapeptide
§6.2Identity by mass spectrometry
[M+H]⁺ at m/z 874.4[3]
§6.3Related substances and degradation
Table 7. Related substances recorded for GHRP-6, with the process or storage route that generates each and its analytical signature.
| Related substance | Origin | Analytical signature |
|---|---|---|
| Tryptophan oxidation products | Oxidation and light | +16 and +32 Da; two Trp residues make this the dominant family |
| L-Trp at position 2 | Incorrect building block | Isobaric; chiral analysis required |
| C-terminal free acid | Incomplete amidation | +0.98 Da |
| Counter-ion | Purification | Proportionally large on an 873 Da peptide |
Degradation routes
- Tryptophan oxidation and photolysis
- C-terminal amide hydrolysis
- Diketopiperazine formation
§7Presentation, reconstitution and storage
§7.1Presentation and reconstitution
- Presentation
- Lyophilised powder in vial (research supply only)
- Reconstitution
- A 5 mg vial with 2.5 mL gives 2 mg/mL; 100 µg is 0.05 mL, that is 5 units on a U-100 syringe.
- Storage, lyophilised
- −20 °C, desiccated, protected from light
- Storage, reconstituted
- 2–8 °C protected from light; no in-use claim
- In-use period
- No supported claim
Light protection is essential. A double-tryptophan hexapeptide left in clear glass on a bench loses measurable purity within days.
§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.