SAXS is a powerful analytical method for determining the dimensional parameters and structure of nanoscale particulates. The method is based on the registration of X-rays scattered by the sample at very low angles with the use of dedicated instruments. The SAXS method is applicable to any particulates exhibiting a contrast of electron density with the surrounding media, such as biopolymers in aqueous dispersions, nanoparticles in a solid or liquid matrix, or nanopores in a solid matrix.
An important area of application for this methodology is the investigation of drug delivery systems based on nanoparticles, micelles, vesicles or liposomes. The analysis of the scattering data can provide details regarding the binding of the carrier with the active pharmaceutical ingredient (API), the position of the API in the system, and the size and shape of the drug-loaded carrier.
Small angle scattering allows for the reconstruction of the size and shape of any particulate, including specific variations of electron density contrast and other different dimensional invariants. This method is used to determine the dimensional parameters of core-shells, lamellas and sphere-, rod- or disc-type particles. It may also be useful for characterization of the nanoscale morphology of the API and excipients, particularly in nanoscale amorphous domains.
SAXS is a powerful non-destructive method for accessing the distribution of nanoparticles or nanopores by size. Particle size distribution and specific surface parameters (total surface per unit of volume) are the process parameters influencing the processability, reactivity, solubility and bioavailability of the drug substance.
More information is available on the nanoparticles page.