Peptide CMC: Structural Characterisation by XRPD and SAXS

XRPD and SAXS for peptide therapeutics across injectable, oral, and lipid-carrier formulations.

DANNALAB provides XRPD and SAXS structural characterisation for peptide therapeutics, covering injectable, oral, and carrier-delivered formulations. These methods address structural questions that routine purity, identity, and release testing leave open. cGMP documentation is available for selected validated methods.

Peptide CMC Services

Peptide Aggregation & Higher-Order Structure

SAXS in native solution. Detect oligomers, aggregation pathways, and conformational change before bioassays or purity methods show effects.

  • Radius of gyration, oligomeric state, shape
  • Aggregation kinetics and pathway
  • Reversible self-association

Antibody & Fusion-Protein HOS

SAXS envelope reconstruction for antibodies, fusion proteins, and biosimilar comparability work in native solution.

  • Ab-initio envelope reconstruction
  • Rg, Dmax, molecular mass
  • Biosimilar HOS comparability

Lipid Carrier Characterisation for Peptide Payloads

Combined SAXS and WAXS for lipid mesophase, polymorph identification, and drug crystallinity in SLN, NLC, liposomes, and lipid capsules.

See lipid carrier section below →

Peptide API Solid-State Characterisation

XRPD on the drug substance. Confirm amorphicity of lyophilisates, detect residual crystallinity, identify polymorphs and salt forms.

  • Amorphous fingerprinting
  • Residual crystalline phase detection
  • Salt and hydrate identification

Stability Monitoring

SAXS or XRPD at scheduled time points across stress and real-time conditions, with trended structural data for stability narratives.

  • Thermal, mechanical, and freeze-thaw stress
  • Structural trending across time points
  • Stability-indicating parameter design

CMC Structural Comparability

XRPD and SAXS side-by-side comparison of batches, processes, sites, and formulations against predefined acceptance logic.

  • Batch and lot consistency
  • Process and site-transfer comparability
  • Out-of-spec investigation support

Lipid-Based Peptide Delivery

Lipid nanoparticles (SLN, NLC), liposomes, lipid capsules, and self-emulsifying systems (S-SEDDS) are increasingly important for peptide therapeutics. They protect the peptide against degradation, control release, and open delivery routes that injection-only formulations cannot reach.

DANNALAB's combined SAXS and WAXS workflow gives simultaneous information at two structural scales. This is the standard framework for lipid-nanoparticle characterisation established in the canonical review by Bunjes & Unruh (Adv Drug Deliv Rev 59, 2007, 379–402).

Nanoscale (SAXS, 30–700 Å)

  • Lamellar repeat spacing
  • Particle size and shape
  • Electron-density profile
  • Lipid mesophase: lamellar, hexagonal, cubic

Reveals carrier organisation, payload localisation, and phase transitions.

Subcell (WAXS, 3–5 Å)

  • Lipid polymorph: α, β′, β
  • Storage-driven polymorph transitions
  • Drug crystallinity within the matrix
  • Crystalline-vs-amorphous payload fraction

Flags formulations at risk of drug expulsion driven by α → β′ → β transitions.

Method Development with Sponsors

For specialised questions that fall outside our validated workflows, DANNALAB develops fit-for-purpose methods in partnership with sponsors. Each engagement has defined milestones, feasibility gates, and deliverables.

Lipid-Based Oral Peptide Formulations

Structural characterisation of SLN, NLC, and lipid capsules used in oral peptide delivery routes.

Permeation-Enhancer Solid-State

Form characterisation of permeation enhancers (such as SNAC, sodium caprate, and bile-salt solids) used in oral peptide products.

Intact Oral Peptide Tablet XRPD

Methodology for handling excipient-dominated diffractograms and resolving API phase in low-content peptide tablets.

Biorelevant Dissolution + X-ray Residue

Coupled FaSSIF / FeSSIF dissolution with SAXS on supernatant and XRPD on residue.

Research directions under active exploration include pH-stat lipolysis with time-resolved SAXS and other GI-relevant stress simulations. Learn more about DANNALAB Research →

Evidence and Case Studies

Published application notes that demonstrate DANNALAB methods on peptide and protein systems.

Liraglutide in Solution

SAXS structural characterisation of a GLP-1 analogue peptide therapeutic. Tertiary structure determination in formulation.

Read the application note →

Insulin Characterisation

SAXS analysis of insulin: oligomeric equilibrium, structural fingerprinting in pharmaceutical formulation.

Read the application note →

Alpha-Synuclein Aggregation

SAXS study of the aggregation pathway from monomer through oligomers to mature fibrils. Model amyloidogenic peptide system.

Read the application note →

HIV Fusion Inhibitor

SAXS reconstruction of a peptide tertiary structure, validated against the high-resolution crystallographic reference.

Read the application note →

Liposome-Based Drug Product

SAXS characterisation of a lipid carrier system. Lamellar structure, drug loading, and formulation comparison.

Read the application note →

IgG1 Envelope Reconstruction

Solution-state envelope structure of a monoclonal antibody, validated against the high-resolution PDB structure.

Read the application note →

Standards, GMP, and Sample Requirements

Pharmacopeial and Regulatory Standards

  • USP <941> X-Ray Diffraction (harmonised)
  • Ph. Eur. 2.9.33 Characterisation of Crystalline Solids by XRPD
  • ICH Q6A solid-state guidance
  • 21 CFR Part 11 compliant data management

GMP and Quality

  • cGMP available for selected validated methods
  • QA-approved CoA
  • Fast turnaround on committed timelines
  • One of the few EU labs offering SAXS under GMP

View accreditations →

Typical Sample Requirements

  • SAXS in solution: 100 µL at 1–10 mg/mL
  • XRPD on solids: typically 100 mg
  • Combined SAXS and WAXS on lipid carriers: 100 µL of dispersion
  • Lower amounts possible on request

Confidentiality and Shipping

  • NDA available before sample submission
  • Cold-chain shipping accepted
  • Sample retention per project agreement
  • Method development under defined work packages

Discuss Your Peptide Project

Tell us what you need. We respond within 24 hours with a technical assessment and quote, or with a feasibility plan for method development.

Request a Technical Quote Request a Feasibility Review

Biopharmaceuticals · Drug Delivery · Protein Aggregation Testing · SAXS · XRPD