Peptide process and degradation impurities
Deletion, truncation, oxidation and racemization variants isolated or synthesized to support peptide impurity qualification, method development and regulatory filing narratives under ICH Q3A/Q3B and peptide-specific expectations.
4
impurity classes
≥95%
typical purity band
LC-MS
identity on COA
RP-HPLC
assay method
Q3B
qualification context
Why peptide impurities differ from small molecules
Solid-phase synthesis and downstream handling introduce a predictable set of variants: truncated chains from incomplete coupling or cleavage, deletion peptides missing one residue, oxidized Met/Trp/Cys forms, and epimerized positions from racemization during activation or deprotection.
Parent-drug-relative reporting (area % vs API) is common in peptide files. Standards are often supplied at a purity tier suitable for spiking and bracketing in RP-HPLC or LC-MS methods; exact limits remain drug- and region-specific.
Impurity classes we routinely supply
Each lot is characterized for identity and nominal purity; impurity profile of the standard itself is disclosed on the certificate of analysis.
Deletion & truncation
- Single-residue deletion peptides along the sequence
- N- and C-terminal truncated sequences
- Des-amino (pyro-Glu) and related N-term variants where applicable
Oxidation
- Met sulfoxide and Met sulfone
- Trp oxidation products
- Disulfide scrambling / mismatched cysteine pairing
Racemization
- D-isomer content at labile positions (e.g. Asp, His, Cys)
- Diastereomeric mixtures where epimerization occurred at a single site
Other
- Aspartimide and β-aspartyl motifs in Asp-Gly sequences
- Deamidation (Asn/Gln) where stability data support shelf life
Indicative control and qualification posture
Figures are indicative industry-typical values. Lot- and project-specific data appear on the quotation and certificate of analysis.
| Impurity type | Typical origin | Analytical handle |
|---|---|---|
| Deletion / truncation | SPPS coupling failure, partial cleavage | RP-HPLC UV; LC-MS confirms mass offset |
| Oxidation | Storage, downstream contact with peroxides | Separate peaks in HPLC; MS +16 / +32 Da |
| Racemization | Activation bases, His/Asp adjacent motifs | Chiral HPLC or chiral LC-MS where developed |
| Des-amido / deamidation | pH and time in solution | Mass shift −17 / +1 Da patterns |
Figures are indicative industry-typical values. Lot- and project-specific data appear on the quotation and certificate of analysis.
Typical certificate of analysis contents
Binding specifications appear on the quotation and lot COA.
Identity
LC-MS (m/z)
Expected vs observed mass
Assay (purity)
≥95–≥98%
RP-HPLC area % at 220 nm typical
Water
KF or LOD
As required for storage class
Residual solvents
ICH Q3C screen
When applicable to isolation route
Storage
−20 °C or 2–8 °C
Sequence- and form-dependent
Related substances in standard
Reported
Peaks >0.1% area typically listed
Figures are indicative industry-typical values. Lot- and project-specific data appear on the quotation and certificate of analysis.
Indicative method development workflow
Laboratories often bracket deletion and oxidation standards around the parent peptide retentions.
- 01
Define target list from forced degradation and batch history (deletion, truncation, oxidized forms).
- 02
Source or synthesize standards at a stated purity band; verify identity by LC-MS.
- 03
Optimize RP-HPLC gradient to resolve critical pairs (especially truncation vs deletion).
- 04
Establish response factors if non-UV-equivalent; document in validation protocol.
- 05
Update filing limits as manufacturing process knowledge improves.
What you receive
- Material with lot number and retest or expiry guidance
- COA: identity, assay, related substances in the standard
- Safety and storage information (SDS on request)
- Traceability statement to synthesis or isolation batch record
- Quote tied to CAS (where assigned), sequence and scale
Frequently asked questions
Parent API reference can be quoted separately. Many teams already hold in-house API and only need the isolated or synthesized impurity peak.
Related
Chiral Impurities
Enantiomers and diastereomers as traceable standards for chiral HPLC, chiral LC-MS and ICH Q6A/Q11-related impurity control — with stated enantiomeric or diastereomeric excess on the certificate of analysis.
View detailsCustom Impurity Synthesis
When catalogue search does not return your peak, we design a synthesis or isolation route for deletion peptides, genotoxic alerts, nitrosamines, metabolites and chiral variants — with a documented package for qualification.
View detailsWorking Standards
Secondary working standards traceable to primary or certified reference materials — qualified under ISO/IEC 17025-style laboratory practice for daily HPLC, GC and titre use without consuming CRM inventory.
View detailsStable-Isotope Standards
Deuterated and 13C-labeled impurities, metabolites and APIs for isotope dilution quantitation — minimizing matrix suppression effects in bioanalysis and nitrosamine confirmatory methods.
View detailsReady to specify this for your program?
Share sequence, scale and documentation needs. We reply with indicative specs and a project-specific quotation.