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.
As an example; for the case of drug loaded in liposomes, we are able to obtain information about the thickness and density of lipid bi-layers, the PEG corona and the dimensions of a nanocrystalline loaded drug. You can find a full test case here.
An application note with an example of a SAXS analysis of the sodium dedecyl sulfate (SDS) micelle is available
here.
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 the polymorphic contents of the API, the quantity of the API within one dose and the dose repeatability.
Drug carriers (i.e., microspheres, liposomes, nanoparticles) may be accessed using SAXS and complementary methods when entering the fluid phase.
The characterization of liquid formulations is similar to that used for the characterisation 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.
Please follow this link Devices and materials for more information.
