SAXS for Drug Delivery Systems
Nanoscale structural characterization of liposomes, lipid nanoparticles (LNPs), nanoemulsions, and advanced delivery carriers using small‑angle X‑ray scattering.
Lipid‑Based Nanoparticles Evaluated with SAXS
For various drug delivery systems — such as liposomes, nanoemulsions, solid lipid nanoparticles, and nanostructured lipid carriers — SAXS (Small‑Angle X‑ray Scattering) is a valuable tool to reconstruct the nanoscale structure of the carrier, either in its unloaded form or when loaded with a drug.
The structural information obtained can include the type of lipid phase (e.g., lamellar, hexagonal, or disordered), periodicity, electron density distribution, and the spatial arrangement of different components within the nanoparticle.
Understanding how these structural properties depend on factors such as temperature, pH, and concentration is crucial for optimizing and designing effective drug delivery carriers.
SAXS Applications for Drug Delivery
Liposomal Formulations
Characterization of lipid bilayer thickness and density, PEG corona dimensions, and nanocrystalline drug loading within liposomes.
Lipid Nanoparticles (LNPs)
Structural analysis of mRNA‑LNP assemblies, lipid organization, and particle morphology for gene therapy and vaccine applications.
Micelle Structure
Determination of micelle size, shape, and internal structure for surfactant‑based delivery systems.
Nanoemulsions
Size distribution and interfacial properties of oil‑in‑water and water‑in‑oil nanoemulsions.
Solid Lipid Nanoparticles
Crystalline structure of lipid matrix and drug distribution within solid lipid nanoparticles (SLN).
Nanostructured Lipid Carriers
Mixed lipid phase characterization and drug encapsulation efficiency in NLC systems.
mRNA & siRNA Lipid Nanoparticle Characterization
SAXS provides critical structural insights for nucleic acid-loaded lipid nanoparticles used in mRNA vaccines, siRNA therapeutics, and gene therapy applications.
From early formulation development through cGMP batch release, SAXS reveals the internal organization that determines delivery efficiency and stability.
Ionizable Lipid Systems
Characterization of LNPs containing ionizable lipids (SM-102, ALC-0315, MC3/DLin-MC3-DMA) — the key components enabling endosomal escape and cytoplasmic delivery.
mRNA Encapsulation
Structural analysis of mRNA organization within the LNP core, lipid phase behavior, and electron density distribution affecting payload protection.
siRNA-LNP Assemblies
Characterization of siRNA lipid nanoparticles for RNAi therapeutics, including those similar to approved products like Onpattro (patisiran).
Multilamellar LNPs (MLNPs)
Analysis of multi-layered lipid nanoparticles offering enhanced payload capacity and sustained release profiles for nucleic acid delivery.
Key Parameters for mRNA/siRNA-LNP Development
Lipid Phase
Lamellar, hexagonal, or disordered organization
Core Structure
Electron density profiles and RNA localization
Size & PDI
Particle distribution for regulatory compliance
Thermal Stability
Structure under storage and stress conditions
Oncology Drug Delivery Applications
Lipid nanoparticles and liposomes are at the forefront of cancer therapeutics — from established chemotherapy reformulations to next-generation mRNA cancer vaccines and targeted delivery systems.
mRNA Cancer Vaccines
Structural characterization of personalized neoantigen vaccines and cancer immunotherapy formulations delivered via LNPs.
Liposomal Chemotherapy
SAXS analysis for Doxil-like pegylated liposomal formulations, encapsulation verification, and bilayer characterization.
Targeted Delivery Systems
Characterization of actively-targeted LNPs with surface ligands for tumor-specific accumulation and EPR-optimized particle sizes.
Combination Therapy Carriers
Multi-drug co-loaded nanoparticles for synergistic cancer treatment — structural analysis of multi-component systems.
Stimuli-Responsive LNPs
pH-sensitive, temperature-responsive, and enzyme-triggered delivery systems for tumor microenvironment-activated release.
In Vivo Gene Therapy
LNP carriers for CAR-T mRNA delivery and CRISPR-based oncology applications requiring precise structural control.
Aerosols for Lung & Nasal Delivery Routes
The lung and nasal delivery routes are commonly used for aerosols. This is a promising delivery route, yet accurate and repeatable dosing remains a technological challenge.
Once a pressurized dose of an aerosol is delivered to the sampling surface, the most important factors to control using XRPD are:
- Polymorphic content of the API
- Quantity of the API within one dose
- Dose repeatability
Drug carriers (i.e., microspheres, liposomes, nanoparticles) may be assessed using SAXS and complementary methods when entering the fluid phase.
Ophthalmic & Otic Delivery Routes
The characterization of liquid formulations is similar to that used for the characterization of drugs with an injection delivery route, and are performed using the SAXS methodology.
Characterization of liquid‑crystal‑based formulations is performed using a combination of SAXS and XRPD techniques.
Liquid Formulations
SAXS characterization of nanoparticles, vesicles, and colloidal structures in ophthalmic and otic solutions.
Liquid‑Crystal Systems
Combined SAXS/XRPD analysis of lyotropic liquid crystals for controlled release applications.
In‑Situ Gel Systems
Structural transitions and gel formation monitoring under physiological conditions.
Transdermal Delivery Route
For transdermal delivery systems including patches and topical formulations, XRPD provides critical information about API solid state and distribution within matrices.
Key Structural Parameters
SAXS analysis of drug delivery systems provides quantitative structural parameters:
Lipid Phase Type
Identification of lamellar, hexagonal, cubic, or disordered lipid phases.
Bilayer Dimensions
Thickness, repeat spacing, and electron density profiles of lipid bilayers.
Particle Size & Shape
Radius of gyration (Rg), particle size distribution, and morphology determination.
PEGylation
Characterization of PEG corona thickness and density in stealth liposomes.
Drug Loading
Detection and localization of crystalline or amorphous drug within carriers.
Temperature Dependence
Phase transitions and structural stability as a function of temperature, pH, and ionic strength.
DANNALAB Capabilities
cGMP SAXS Testing
cGMP‑compliant SAXS characterization with 21 CFR Part 11 traceable data and QA‑approved deliverables.
Method Development
Collaborative development of fit‑for‑purpose SAXS methods for novel delivery systems.
Temperature Control
In‑situ SAXS with precise temperature control for phase transition and stability studies.
Model Fitting
Advanced modeling including core‑shell, bilayer, and multi‑component systems.
Small Sample Volumes
Analysis possible with minimal sample quantities in native formulation buffers.
Combined SAXS/XRPD
Integrated characterization using both techniques for comprehensive structural understanding.
Regulatory & Development Support
DANNALAB provides SAXS characterization data suitable for regulatory submissions across multiple pathways — from IND-enabling studies through commercial batch release.
505(b)(2) Applications
Structural characterization supporting new formulations of approved drugs, including LNP-based reformulations of existing therapeutics.
IND-Enabling Studies
CMC characterization data packages for Investigational New Drug applications with cGMP-compliant documentation.
Batch Release Testing
Routine SAXS testing for manufacturing consistency and critical quality attribute verification.
Comparability Studies
Structural comparison between batches, manufacturing sites, or process changes to demonstrate product consistency.
Related Services
SAXS Method Information
Detailed technical information about our SAXS methods and capabilities.
Nanoparticles
Characterization of inorganic and organic nanoparticles for pharmaceutical applications.
Biopharmaceuticals
SAXS for proteins, peptides, and biologics in native environments.
Discuss Your Drug Delivery Project
Contact our technical team to discuss your drug delivery system characterization needs, request a quote, or get expert advice on SAXS method development.