Radar charts based on particle sizing as an approach to establish the fingerprints of polymeric nanoparticles in aqueous formulations

Abstract

Pre-formulation studies are conducted each time new nanoparticulate formulations are in development to the selection of a satisfactory drug delivery system. We hypothesized that laser diffraction technique could be used as an initial screening, being an excellent tool to save time and reduce the number of necessary tests to select formulations. We built radar charts based on laser diffraction data as a new approach to determine the fingerprints of nanocarrier formulations in order to select promising drug delivery systems. To validate our approach different lipophilic dispersions of poly(epsilon-caprolactone) and polysorbate 80, combined with 4 solid materials: sorbitan monostearate (I), cetyl palmitate (II), stearic acid (III) or cholesterol (IV), and 4 oils: capric/caprylic triglycerides (A), mineral oil (B), octyl methoxycinnamate (C) or oleic acid (D), were prepared. Formulations were analyzed by laser diffraction, as well as considering the visual appearance, pH, organic phase viscosity, hydrodynamic diameter, polydispersity index, zeta potential and in vitro drug release. Specific fingerprints were determined for formulations having unimodal particle size distributions with low polydispersity. On the other hand, formulations showing multimodal particle size distributions were rapidly identified in the radar charts and classified as noncompliance products.