The Nanotechnology Characterization Laboratory will evaluate drug release from a nanoparticulate formulation in vitro in human plasma, using a novel stable isotope tracer ultrafiltration assay (SITUA) developed at the laboratory. The SITUA is a method to fractionate encapsulated and unencapsulated drug (active pharmaceutical ingredient) administered as a nanoparticulate formulation in plasma matrix. Advantages of the method include increased accuracy and precision in comparison to other available methods of assessing nanomedicine release. The evaluation of formulation stability and drug release in biological matrix is a key step in the early development of nanomedicine formulations, and it can also be used as a bioassay for product lot release.
The nanoparticulate formulation will be incubated in human plasma, and aliquots of the incubate will be prepared at predetermined time points using the SITUA method and analyzed using an established bioanalytical method. The Nanotechnology Characterization Laboratory will calculate drug concentrations for the various nanomedicine fractions, including (a) nanomedicine-encapsulated, (b) unencapsulated free-unbound, and (c) unencapsulated protein-bound. The data will be analyzed to determine an in vitro drug release profile. Sufficient basic consultation with Stephan Stern, Ph.D., senior principal scientist and head of pharmacology and toxicology at the Nanotechnology Characterization Laboratory is included as part of the service to address technical questions regarding the method and results, and to assist with data interpretation.
More details on the SITUA can be found in the following publications:
- Skoczen S, McNeil SE, Stern ST. Stable isotope method to measure drug release from nanomedicines. J Control Release, 2015;220(Pt A):169–174.
- Skoczen SL, Stern ST. Improved ultrafiltration method to measure drug release from nanomedicines utilizing a stable isotope tracer. Methods Mol Biol., 2018;1682:223–239.