Poloxamer-Driven Drug Delivery System for Anti-Inflammatory Drugs Using Small-Angle Neutron Scattering Approach

Poloxamer-based drug delivery systems are widely used in the pharmaceutical sector. The structural characterization of these systems is crucial for the development of new drug delivery systems and for the optimization of their properties. In this study, we utilized small-angle neutron scattering (SANS) to investigate the structures of poloxamer-based drug delivery systems. The samples were measured using the SANS technique on the VSANS-V16 instrument at Helmholtz-Zentrum Berlin (HZB), Germany. The samples contained 20% poloxamer (P407) and 0.2% of a drug (ibuprofen, ketoprofen, diclofenac) in deuterated water (D₂O) for SANS. The samples varied in terms of temperature analysis (25 °C, common storage temperature; 37 °C, human body temperature; 40 °C, fever temperature). The data analysis involved modeling the data using a Python-based routine. The model used consisted of an isotropic solution of polydisperse spherical micelles. The intensity as a function of the scattering vector was modeled as the product of the form factor and the interparticle structure factor, with the latter described within the local monodisperse approximation regime. Additionally, a scattering contribution was observed, which was associated with the presence of crystalline superstructures formed by micelles that organized into a cubic structure. The data analysis provided important information about the system, such as the average radius, the size distribution, and the thickness of the layer surrounding the micellar core. The results will contribute to the development and optimization of new drug delivery systems that are more effective and safer for medical applications.