Process intermediates and fine chemicals
Isolated intermediates, starting materials and fine chemicals that double as impurity references when carryover must be tracked in API specifications — each with identity data suitable for registration and supplier qualification.
GMP
grade optional
ICH Q7
alignment
COA
full identity
ppm
carryover limits
Custom
route match
Intermediates as specified impurities
When a synthesis step leaves a characteristic structural remnant, the isolated intermediate may become the official reference for limit testing even if it is not present at high levels in the final API.
Fine chemicals used as reagents (e.g. coupling agents, chiral auxiliaries) can appear as trace impurities if not washed out — having an authentic standard speeds method development.
Typical supply specifications
Identity
NMR, IR, MS
Structure matches route drawing
Assay
≥95–99%
Figures are indicative industry-typical values. Lot- and project-specific data appear on the quotation and certificate of analysis.
Related substances
HPLC
Downstream impurity precursors noted
Residual metals
ICP-MS if catalyst route
As per customer spec
Documentation
COA + optional DMF support letter
Project-dependent
Figures are indicative industry-typical values. Lot- and project-specific data appear on the quotation and certificate of analysis.
Supplier and impurity qualification flow
Map route
List all isolated intermediates and likely carryover structures from each step.
Source standard
Match or synthesize each structure for HPLC spiking.
Set limits
Apply ICH Q3A thresholds or justify lower based on toxicity.
Control in release
Include in API specification if carried forward per purge calculations.
Deliverables
- Material with route-relevant purity tier
- COA and SDS
- Pack size from gram to kilogram scale
- Stability and storage recommendation
- Custom synthesis when commercial supply is unavailable
Frequently asked questions
Overlapping chemistry, but impurity use emphasizes authenticated structure for analytical methods rather than bulk manufacture.
Related
Custom 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 detailsCertified Reference Materials
Impurities and API-related CRMs with certified property values, measurement uncertainty and metrological traceability — produced or distributed under principles aligned with ISO 17034 for method validation and lab accreditation.
View detailsChiral 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 detailsReady to specify this for your program?
Share sequence, scale and documentation needs. We reply with indicative specs and a project-specific quotation.